Yeehow Central

Owyhee Figs. 2 and 1...Last post of these, I promise.

2011-02-02T11:19:00.001-08:00

Posted for co-author review...interloper review also accepted, but maybe not taken as seriously.

And it continues...

2011-02-01T16:09:00.001-08:00

Sure I love making geologic maps, but this is becoming ridiculous. Just a few hours left on the Hole in the Ground map before I move way on.

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Best guess Owyhee River path pre-West Crater lava (70 ka)

2011-02-01T15:11:00.001-08:00

In the first attached image, I have drawn the pre West Crater lava flow course of the river. I based this on the presence of Tsv rocks in section along the western edge of the flow as well as the thickness of lava over Tsv, paleo Ryegrass Creek remnant, the big kipuka, Augerville...the big flat area bounded by large inflationary structures, the weird pressue plateaus with craters, the fact that landslides most often bound the margin of the river, and other space constraints.

Recall how I always point out that the desecrated mud stack seems to sit too low to mark the flanks of a pre-West Crater valley? Well, I accept it and used an estimate of the basal elevation to build a contour to see what other familiar areas the paleovalley floor could possible relate to...some of these areas include:

The prominent flat surface just below the northern exposure of the Saddle Butte lava...why have I never stepped down on that thing?

The boulder line...the conspicuous line of basalt boulders that may relate to pre-Qbw degradation of the edge of the Qbs flow.

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Owyhee Figure iteration 9076b-44m

2011-02-01T10:17:00.001-08:00

Why is it that everyone finds something wrong with this except for me?

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Back to being my own graphics department

2011-01-31T16:39:00.003-08:00

Oh well. Take the good with the bad.

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Psychedelic rendition of the NV-OR-ID borderland

2011-01-31T16:39:00.001-08:00

Repeating color ramps are not only seriously awesome, they are also amazingly instructive about regional geology and geomorphology. Made this number with Globalmapper. The Owyhee River watershed is the conspicuous one.

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Lava-paving and long profile development

2010-12-29T09:30:00.001-08:00

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New and improved with scale and slopeshaded base

2010-12-22T07:25:00.001-08:00

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The West Crater Lava Dam figure. Draft.

2010-12-21T16:19:00.001-08:00

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Owyhee Map Draft 994a-2c

2010-12-20T10:32:00.001-08:00

The never-ending map continues to never end. I call this good enough for manuscript review, don't you?

PS. Really missing graphic / cartographic support staff. Yikes.

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Lava v. River, the case of the the Owyhee River

2010-12-17T15:30:00.001-08:00

Seems like it took >1.8 My to make this damn thing.

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Second draft of Owyhee River and lava profile

2010-12-17T14:38:00.001-08:00

Thanks to JEO'C for his input. Here is the latest version. Still draft, but much better.

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Let the monkeys and pigs fly from where they may

2010-12-16T15:00:00.001-08:00

I have finally compiled a freaking diagram of longitudinal profile data extracted from the geologic map, the LiDAR data, and my field observations. I will never reveal truly how long this took. Still...only a draft. Shoot me anytime.

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Intracanyon lavas: 1m contours from LiDAR

2010-12-16T11:07:00.001-08:00

AM-PM campsite on the Owyhee River for those in the know. Made with GlobalMapper.

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Second draft, Owyhee Map

2010-12-02T15:25:00.001-08:00

A few hours and a few suggestions later.

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Draft Owyhee lava figure

2010-12-02T09:50:00.001-08:00

A tedious work in progress.

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Some Owyhee River landslide images with contours

2010-11-12T09:49:00.001-08:00

Made with Global Mapper in order to evaluate topography related to landslide damming and overflow.

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Heavy Landscape Visualization: Owyhee River area

2010-11-10T15:46:00.001-08:00

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Owyhee River lava paleomag sites

2010-11-10T15:43:00.001-08:00

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Owyhee River Map going global

2010-09-02T13:35:00.001-07:00

Sent via Android.

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2010 UNR Geology Field Camp Maps

2010-06-21T08:54:00.001-07:00

A particularly good year in a very complicated area. Collage includes the NAIP image and my map...now to grade them and all the related items by the end of the day.

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Field tour

2010-06-19T09:30:00.001-07:00

This year's field camp made the full trip around the Owyhee map
area...in spite of unfounded concerns by some local officials that the
vans just couldn't make it. We made it. Not a single issue with the
vans...so there.

See the full gallery on posterous

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Another year, another field camp.

2010-06-19T08:38:00.001-07:00

A week of crazy weather, rattlesnakes, and extreme geology and
geomorphology has come to an end. This year's field camp was
exceptionally good. Managed to get 24 students well up to speed on
intracanyon lava flows, immense and numerous landslides, and
catastrophic flood deposits in a matter of days. Most of the students
will agree that they got nearly a semester's worth of education in one
week.

This year we mapped part of the Hole in the Ground along the Owyhee
River and camped at Birch Creek. A brilliant plan.

See the full gallery on posterous

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Attabad spillway video

2010-06-10T12:23:00.000-07:00

This is from Dave's Landslide Blog:

Attabad spillway video: "Thanks to a number of people for drawing my attention to the Hunzaonline video on youtube that shows the spillway in action. The caption indicates that this was collected on the 8th June:

Three observations about this video:

It shows that the major restriction on flow is still the large boulder at the saddle of the spillway;
A second boulder has formed substantive constriction downstream as well, but this is not controlling the overall flow
There is still considerable scour occurring, especially on the downstream side of the boulder, upstream of the boulder towards the neck of the channel, and elsewhere on the banks of the channel.

Meanwhile, the Pamir Times reports that 'An international expert reportedly suggested the government to blow two large boulders present in the spillway but the government has decided to act against the suggestion'.

In case anyone was wondering, that expert is not me! Whilst I wouldn't completely rule out the possibility of a controlled blast, this would need to be undertaken with extreme care, and only after a full analysis of the consequences had been undertaken. I would in particular want to see an evaluation of the likely flood that the blast might trigger, and the potential for triggering further slides on the sides of the valley. However, this is not an excuse for inaction - NDMA really need to move quickly now to evaluate the range of options, and to communicate the pros and cons more widely.

As per my post yesterday, I will use the Hunza Monitoring Site to host updates on the situation at Attabad, and this site to provide a commentary. I will put a new set of data on the monitoring blog later this morning.

Owyhee Map at 1:50,000

2010-06-09T16:33:00.001-07:00

Almost there...this is the version to support the Field Camp tour next weekend. It shows the various vents, etc.

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Oh right...the Owyhee Map...almost forgot about it.

2010-06-08T21:32:00.001-07:00

For various reasons, I have dropped the Clark County mega-mega map for a day to work on the very nearly complete Owyhee River area map. In real life, this map is 40 inches by 40 inches at 1:36,000. Although I have compiled the mapping in the river corridor down to about 1:4500 in most places. Heading out to teach field camp there in a couple of days. Learned some handy new tricks in ArcGIS that really have improved map data management and symbolization. Will share them when my cloning experiment is successful.

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The Jackson Creek lava delta and the 'two' Bogus lavas

2010-04-28T22:35:00.000-07:00

The upper photo is a slightly less common shot (for our group at least) of the Jackson Creek lava delta. We usually see this from the river and look mainly at the south-facing exposure. This is the north-facing exposure. Since I took this picture a while back, I have actually walked out on that outcrop to get a gigapan image of Jackson Hole. In so doing, I found that the two conspicuous lava flows are separated by the lacustrine silt package indicated in the previous post. No surprise given that the outcrop is right across the trib canyon from the much better exposure shown in that post. The difference in quality of exposure of the lacustrine silts is controlled by the presence of a thick lag of Bogus Rim lava mantling the surface.

The photo below is the 'classic' view of this outcrop (taken almost exactly two(!) years ago). The lava delta is associated with the lower Bogus lava unit. You can't see the intervening lacustrine silt package, but the Bogus Rim lava at the top is obvious.

Lacustrine sediment between Bogus Rim lava and older Bogus lava

2010-04-28T22:22:00.000-07:00

The photo below is looking north across Jackson Creek Canyon on river left. The upper lava is good ol' Bogus Rim, the white stuff is probably lacustrine silt. The little wedge of lava upon which the silt lies is what I call the lower Bogus...but may correspond to the Bogus Point lava (?).

Click on the image to enlarge. The wedge that sits conspicuously below the silt has a couple of companion wedges on the canyon wall below where I am standing. It is clearly inset into the older rocks. Note that the higher wedge that is perched on the silts is a small landslide block of the Bogus Rim lava.

Note also how the lacustrine silt grades abruptly upward into bedded gravel. As the image below attests, some of the light colored fines are interbedded with the trib gravels. The Bogus Rim lava is also capped by the gravels in this outcrop.

Upstream-most remnant of West Crater Lava on river-left

2010-04-28T22:01:00.000-07:00

I don't think I ever shared photos from our trip last May. My, how time flies. This is the tiny wedge of lava that survives across the river from the bulk of the flow upstream from Dogleg Bar.

Three distinct basalt flows below Bogus Rim?

2010-04-28T21:55:00.000-07:00

This first photo is looking west into a basalt-choked tributary valley just downstream from Iron Point. I recall inferring three major intracanyon flow units here divided by conspicuous breaks. Just throwing it out there for all to consider.

This photo is looking upstream from west side of the river (near Rinehart Mesa) toward and beyond Jackson Hole. The intracanyon flow sequence here is very thick. Possibly three units here as well? The lower shelf right above the talus slope has the 'hackly' texture that we see at the base of the section near Rinehart Creek as well.

Young Basalts in Yeehow-ville: Even more ruminations from Duane!

2010-04-28T21:34:00.000-07:00

[all...once I clone myself, I will add annotated images to these discussions...Kyle]

The Junction of Crooked Creek, and the Owyhee River

The air photos help to see more details in the vicinity of where Crooked Creek joins the Owyhee River. This is an area that Kyle, Cooper, and I have briefly mused over. I think I see three (3) different young basalt flows in this area. There is an odd “comet-shaped” lobe of lava which enters Sect. 31, T30S, R41E located in the SW corner of the Owyhee Butte quad from the SSW. There it has an omni-directional scarp which rolls over at about 3640’, which is lower than adjacent surfaces to the N and SE of the lobe. This lobe seems to be a northerly extension of the lower of the double outcrop that Bill Hart argon dated just N of the State Wayside Park, at 1.25 ± 0.28 Ma. The younger of the two E-facing scarps that Hart dated at 0.91 ± 0.36Ma, is located just a half mile to the W of this odd shaped outcrop, and forms a surface that rolls over at the higher elevation of 3720’. A third surface which enters this same immediate area from the E, coming from Little Owyhee Butte across the present course of the Owyhee River, seems to directly overlie the odd shaped lobe, and rolls over at a higher elevation of just lower than 3700’, and is separated from it by thin, light colored sediments.

So what do we have here? I think the odd shaped lobe is stratigraphically oldest, probably the Little Owyhee Butte lavas from the E are next, and that the E-facing scarp and surface to the W is the youngest. There is an odd meander in the course of the Owyhee in Sect. 32, T30S, R41E, rather square in map view, that is created by the eastward continuation of the lava flows of the odd shaped lobe, passing underneath the Little Owyhee River lava flows. I have a paleomagnetic site, in what I thought was Little Owyhee Butte lava flowsjust N of this area, that doesn’t fit so well with the other sites. I now wonder that it samples not Little Owyhee Butte, but the lava flows which come into the area from the W at the highest level. More sites on both sides of the Owyhee River will help decide this. Although surface degradation is the general process of this area through the last 4 Ma, these 3 units stack during a period of aggradation. I wonder how long it lasted? The NE projection of the oldest odd shaped lobe, and the W projection of the Little Owyhee Butte lava flows I believe is telling us about the location of the junction between Crooked Creek and the Owyhee River at the time of these eruptions. Not really that far from the current junction, located just to the SE.

Lastly, another curiosity for investigation to the south. In the area just N and E of where Crooked Creek crosses Hwy 95, the creek flows in a fairly sharp canyon for about 3 miles. The E and W rims of the canyon are at very comparable elevations, and we know that Bill Hart sampled the W rim from basalt flow outcrops for his argon age experiment. So I guess the E rim will probably be basalt lava flow outcrop too. But, that dark surface and dark layer passes laterally to the E all the way to the Cliffs of Rome, where I believe Caitlin showed me the odd erosional sediment columns of that area. I half remember the dark layer, but I remember it as a coarse fragmental layer, and not as any kind of lava flow. Can we see the transition of one of these basalt flows becoming deltaic, then fragmental, proceeding to a cemented black basaltic sand layer pro-delta? Is the transition from flow to fragmental about where a N-S canyon has be cut through the layer just SSE from Crooked Creek Ranch? The Rome 7.5’ quad shows quarries in this layer. What are they quarrying? Broken basaltic fragments just the perfect size for road metal? I can’t wait for the roads to dry out!

Area East of Saddle Butte

The air photos have clarified my thinking about “young” vents E and N of Saddle Butte. I believe the W-E “breadloaf”of lava located just S of Wrangle Butte is in fact a badly eroded isthmus between a lava flow field from vent 4373’ in the extreme NE corner of the Saddle Butte 7.5’ quad, and a S-sloping lava flow field bounded by Bull Creek Canyon, the Owyhee River, and a S-facing scarp located just N of Ryegrass Creek. Some field inspection S of Wrangle Butte near Top Hat Reservoir is required. The S margin of the flow field from vent 4373’W of this constriction is either Bull Creek, or a parallel drainage just to its south. Near Ryegrass Creek the lowest scarp from this flow rolls over at about 3780’ which is low, but not as low as other “young” scarps. Therefore, rather young, but perhaps not as young as 2 Ma. This lava flow field looms over Chalk Basin, and projects eastward forming the Basin’s S boundary in the Lambert Rocks 7.5’ quad. The last basalt flow outcrops appear again at about 3780’ in this area, but E and forward of those outcrops are broad, smooth patches of strongly oxidized sediment(?) that I wonder are palagonitized fragmental basalt and basalt sand. Is this another place where we can inspect the transition from subaerial basalt flow to lake sediments?

The photos have helped me decide that there is a basalt shield at the E base of Saddle Butte, with a vent at 4302’, that forms a lava flow field to the E and S, which rims the prominent SE-facing scarp that dominates the Wrangle Butte 7.5’ quad. This scarp breaks over at 4120’, is thus rather high and probably not all that “young”. As if I actually know what that means! The N end of this scarp is at Chanis Rock, which is the last place to actually see the rim basalt flow clearly. The N boundary of this flow field extends W from Chanis Rock, and is an important part of my reasoning that these flows come from vent 4302’, and not from Saddle Butte itself. There is thus a fat septum between this flow field, and the one described in the previous paragraph composed of rolling topography sloping E off Saddle Butte. This must be even older ground.

Lastly, the photos helped me note that S of Ryegrass Creek, in and amongst the terminating lobes of the 144 ka Saddle Butte lava field, is a low E-facing scarp. The 144 ka flow dump over this scarp, and mask it to some extent, but it extends all the way to the Owyhee River, and forms the walls of the unnamed canyon which contains Sand Spring, and a minor lobe of the 144 ka flows. Anyway,,,, off to the SW I lost view of a NE directed lobe of lava from the 4257’ vent in the Palomino Lake 7.5’ quad, because it was covered by the lava flow field of the 144 ka event. Is this scarp the terminus of the older flow lobe? This scarp rolls over at about 3700’, or perhaps a little lower. The lower elevation outcrops are softer, rounder, and subdued, making me wonder that again we can witness the transition from sharp, blocky subaerial basalt flow, to lava delta, to fragmental layer, to glassy, basalt sand fringe. Easy to get there and take a look. Other scarps associated with vent 4257’ lava lobes, roll over at elevation quite a bit higher than 3800’, so perhaps it is incorrect to associate these lower elevation scarps with that vent. Start the drill! Let’s see what correlates.

Sacramento Butte

High ground 2 mi east of Sacramento Butte, that I am calling vent 4411’, seems to be the source of basalt flows with high elevation margins. Consequently, it may be rather old. Lava flows from it embay Sacramento Butte from the E, and pass both S and N of Sacramento Butte flowing W. An easily identifiable lobe is directly S of Sacramento Butte in the SE corner of the Sacramento Butte 7.5’ quad, and ends at a scarp rolling over at 4220’. Lower and Upper Clark Reservoirs are in the drainage that separates this lobe from Sacramento Butte. The vent 4411’ lava flows loom over, and form the W rim of Sand Basin and are found at variable elevations near 4300’. This scarp is erosional, and has to have retreated westward at least to some extent. Again, these flows are way up in the air, and may be 4 Ma old. The square shaped high mesa that looms over Rinehart Ranch on the W, may be a continuation of this flow field. My one-time belief that that mesa is just some “old stuff” up in the air is now gone. We will sample the square mesa, and tie it to one of these pre-Bogus rim flows.

So what to make of Sacramento Butte itself? Topography associated with it dominate about 6 sections that slope SW and end at Clark Ranch. A subsidiary knob at 4341’, on Sacramento Butte’s N flank, may be another different basalt vent. If that is the case then the Butte is even smaller aerially! This combined with George Walker’s Oregon state map data that Sacramento Butte is actually not a basalt, but somewhat evolved, makes me wonder that it is an old, masked volcanic center, and not anything of interest to our post-4 Ma geomorphic concerns.

The “Gooseneck” of Jordan Creek

It looks on the air photos that the lava flows from Owyhee Butte loop SE and behind Little Owyhee Butte, and may well make it all the way to the N side of Jordan Creek canyon, to the SW of Hidden Valley. When Kevin and I took the 3 paleomagnetic sites in the area, we just missed stumbling into this awareness, by only a couple hundred meters in one case. So we will go back and put a site into these flows and see what’s what. An odd flat bench, on the SE side of Jordan Creek, may be a continuation of these Owyhee Butte lava flows. They collectively have a SW slope, which does not make much sense for Little Owyhee Butte, but may for Owyhee Butte. An alternative possibility is that these are older flows, related to the NW sloping topography on the SE side of the creek. Doesn’t look hard to get there.

Diamond Butte area – Downstream from Birch Creek pullout

I note something on the photos of this area, which I’m sure Kyle probably already knows. He knows everything first! [check these lavas out in one of my (Kyle) gigapans: http://gigapan.org/gigapans/24823/] About a mile and a half downstream from the meadow at Birch Creek Ranch at which we pull out, are some very interesting outcrops on the E side of the Owyhee River. They are best expressed in the W half of Sect. 5, T27S, R43E. They are a doublet of basalt ledges, the upper one of which extends N almost 3 miles. One of them has to be Bogus Rim, but who is the other one? Better still, farther N on the extension of the upper ledge in Sect. 28, T26S, R43E is a knob with spot elevation of 3235’ that looks HIGHER than the upper ledge in the photos. Could we have three (3) ledges here?

I think we can walk to these outcrops, but it may not be easy. There are two reaches of the Owyhee River that are cliffs plunging right into the water. A jeep trail would get us part way N, but we will have to walk. We can pick up the water late, only at the end of the walk, and carry it uphill to the ledges. Paleomagnetic work here, combined with magnetic work on the ledges W and directly above Birch Creek Ranch, should make quite a package.

vent 4569’ – SE Deer Butte Rim – backside of Bogus Bench

This vent was featured to some extent in Bondre’s recent dissertation. It is in the NE corner of the Bogus Bench 7.5’ map. You can drive right past this vent on the way to Greeley Bar vent and hardly notice it on the ground. But, it has a wonderful, and I think youthful, expression in the 7.5’ topography, breached to the W. No basalt lava flow field to any easy witness, just the cone. The Miami University folks (I don’t remember who now) have a 40/39 age on this at about 5.5 Ma. My guts say no way! I believe that I have UTM coordinates where the sample comes from. I believe that I have loosely played with those coordinates, and that the sample site is W of the cone (which appears in photos to have NO outcrops) from the rim area to its W. If this is true, then the dating sample comes from a potentially scary place. The rim there is a continuation of the rim S of Deer Butte, and looms above Mud Creek at its SW base. Recent age dating puts Deer Butte at about 4 Ma, not 5.5 Ma. Possible that the age experiments are a bit screwed up. But it is also possible that the 5.5 Ma age sample comes from a lower ledge W of the 4569’ cone. S of the 4569’ cone the rim is the lower flow, N of the cone the rim is the Deer Butte flow field. Shannon and I sampled that rim very near Deer Butte Reservoir #2. I will plot the age sample location and see what I see. The lesson here: NEVER let your petrologist collect your stratigraphic and age samples! KEEP THEM IN THE LABORATORY generating data on 40 elements to two decimal places of precision. We will visit this cone this summer(?) and try to sample it. Inspection of the air photos does not lead to optimism.

SW corner of Bogus Bench Mesa

Cooper has called attention to an odd “cascade” appearance to the SW corner of Bogus Bench Mesa. It looks like the Bogus Rim lavas(?) have dumped down over and subdued the sharpness of the rim there. The source of these flows would be knob 4432’, perched right above the edge. But that ridge really is a continuation of vent 4487’ a half mile to the NE. In my “mapping” of Bogus Bench, I separated vent 4487’ from the rest of the rumply relief which seems to be the vent area for the Bogus Rim lava flows. Those vents/flows seem to embay vent 4487’, and are thus younger. At the foot of Bogus Bench is a bench of lava flows that, with a equal grade mirror bench to the S, pinches the Bogus Creek drainage near Bogus Lake. One could entertain the idea that the cascade down from vent 4487(?) makes these benches, which roll over at about 4100’. This places then 150’ higher than the Bogus Rim outcrop that Cooper and I sampled in 2006 at Bogus Falls. OK, higher bench,, older flows,,, vent 4487’,,,, older than Bogus Rim vent!!!!!

ONLY PROBLEM is that the bench S of Bogus Lake is a continuation of topography extending 3 miles E that has been buried by Clarks Butte, Forgotten Butte, and finally West Crater lava flows. The bench really appears to have come from the E, and thus can’t have arisen from any cascade over the SW rim of Bogus Bench. If it comes from the E, it might come from the relatively young Threemile Hill vent, or possibly from the “other” Saddle Butte. I suppose the Arock summit vent is also a choice, by a somewhat convoluted flow path. I also suppose they could correlate to the Bogus Point lava flow, but their higher elevation here would have to be explained away, by a dramatic slope to the W of the topography of that time.

Older topography in this area scares me a bit, as we know that significant down to the N faulting occurs just to our S from this area. Is the old topography in place, or foundered in big blocks to some extent? Tough to know. The air photos give no hint that the bench closest to the SW corner of Bogus Bench is part of the stratigraphy UNDER that bench. I think it is perched against that rim from the S, and thus substantially younger.

I have lost track of the full count of all the possibilities up to this point. TOO MANY CHOICES. What I plan to do is sample the N bench at the Bogus Creek pinch point, and sample the the S bench of the pinch point where the road S to Arock summit crosses the younger, overlapping lava flows. A quarter mile walk W puts me on that topography. We’ll see if they seem to be the same, and what they might compare to. Then, we need to get up on the extreme SW corner of Bogus Bench to take a couple of sites. I am hoping that the road to Bogus Bench Reservoir has been extended since the 7.5’ map was put together in 1972, and that we will only have a short walk. Spot elevation 4371’ looks to me to be a place where we can sample the Bogus Bench which is older, and NOT Bogus Rim lava flows. Just across the ephemeral creek to the N is the foot of the topography from vent 4487’, and maybe we can find an outcrop there. If not, there seems to be a S-facing ledge just W of vent 4487’ that looks like a possibility. So many plans!!
Arock shield – Bogus Point lava field

I have looked hard at both sets of air photos, and for the life of me I can’t see how the Arock summit shield merges with the underlying Bogus Point lava flows. There are a couple of linear gashes to the E of Bogus Creek well, which offer the chance of getting into the flows. But, they seem to be continuations of the W to E faulting that crosses the NW flank of Owyhee Butte, and may be inappropriate places to sample. Kevin and I drove the entire W flank of the Arock shield, and while we saw piles of rocks, we did not have outcrops jumping in front of the truck. We will snoop around, but do not have any concrete plan of action at this point.

Now with lava!

2010-04-16T17:03:00.001-07:00

This reach of the river (looking downstream, btw) provides THE perspective on the role of lava flows in displacing the river and instigating massive slope failure.

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Very cool landslide visualizations: Owyhee River, Oregon

2010-04-16T16:41:00.001-07:00

Using Google Earth pro, a tiled slopeshade map from LiDAR, and an exported and slightly generalized shapefile from my geologic map.

That's right...I chose mint green.

See the full gallery on posterous

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This one is making the rounds in the geoblogosphere...for good reason.

2010-04-16T12:01:00.001-07:00

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Vents-a-plenty

2010-04-15T12:55:00.000-07:00

This unadorned image of the middle Owyhee provides a nice backdrop to recent discussions that illuminate just how many volcanic vents are within our collective field area. This rendition is the slopeshaded 10-m DEM with a stretched color ramp overlay. This one is worth a long look. Note the topographic evidence for lava dams where we know they are, and then ponder where they also may have been. I hope to field check these for pillow complexes early this summer.

The latest iteration of the Owyhee Map...

2010-04-12T18:47:00.001-07:00

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Nearing the end...The Owyhee Map

2010-04-10T12:04:00.001-07:00

I have spent many hours (while on family medical leave, no less) doing
the penultimate pass through the Owyhee map. Not only through the
detailed section but also out into the larger region from which the
lava flows originated.

Theses aren't the most beautiful snippets, but after one more pass,
the map will be nearly ready for external review. There is a chance
that Duane, Cooper, and I will do some additional fine-tuning of some
of the 'other' lava flows out there...you know, the ones we have
largely ignored, but are hugely important in the evolution of the
Owyhee system.

See the full gallery on posterous

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Interesting Ramblings from Duane (with maps from Kyle)

2010-04-08T22:32:00.001-07:00

Young Basalt Fields in and near the Rome Basin

A continuation of the Owyhee River Project, into a somewhat older time domain, offers an opportunity to use the same mix of riverene hydrology, geologic mapping, sedimentology and slope stability, volcanic geology, chronology, and lastly paleomagnetism studies, that were used in a rather younger timeframe. Understanding of the evolution of the Owyhee River system from some network draining a Miocene volcanic upland toward a large freshwater lake in SW Idaho, to an entrenched stream following the Snake River toward the Columbia would be the target we would be after. Lava flows and landsliding, perhaps at an initial “monumental” scale could have impounded lakes along the course of the Owyhee River that might have persisted for some time. I am interested in this work just to figure out the number of separate volcanic events that may be involved. Their separate directions of magnetization are of use to me. Hopefully, you will also find reason(s) to wish to pursue this work.

I have Kyle’s air photos now, and am looking into various “situations” I describe below. I will have additional comments within a couple of weeks to add to those below. So get your 7.5’ maps out, and follow along with my thoughts.

I will discuss these “young” lava fields, as they seem to group/align spatially (and probably temporally as well!) from the NW toward the SE.

NW of Saddle Mountain

There is a SW to NE alignment of young basalt shield volcanoes, to the W and N of Saddle Butte that morphologically seem quite young. The pressure ridges and original topography of the flow field are still evident, and remind me of the general appearance of the Greeley Bar flow field. There are 4 different vents named (in the absence of any real geography) vent 4528’, vent 4556’, vent 4521’, and vent 4373’. They appear in the SE corner of the Turnbull Peak quad, across the Saddle Butte quad, the S half of Mustang Butte quad, and the SW quarter of the Sacramento Butte quad. Their lava flows collectively move S and E to form the N margin of the 144 ka Saddle Butte lava field, embay Saddle Butte proper, and flow off to the NW and NE making the SE margin of “Barren Valley”. I believe they embay an older Mustang Butte, but I need to look at the air photos to be sure. Brennan Jordan argon dated one of these flows along the road to Rinehart Ranch, before you even get as far in as Crowley. He obtained an age of 1.40 ± 0.04 Ma from BGC. Pretty damn young!

Why should you care? – How these flows “finish” to the E is not clear to me. They may have interacted with “lake(s)”of the Owyhee River in the Wrangle Butte quad area. One flow tries to sneak S of Saddle Butte, but seems be be pinched off by Saddle Butte topography W of Rattlesnake Cave.

Another flow clearly is moving SE past the SW of Wrangle Butte, but what happens to it in the Bull Creek drainage is again unclear. The topography between Wrangle Butte and Chanis Rock also seems odd. It is kind of an E facing scarp, and a continuation of the more pronounced E facing scarp to the E of Saddle Butte. I wonder that an W-E “bread loaf” of topography between Top Hat Reservoir and Bull Creek is an eastward continuation of these “young” lava flows. Farther E a platform of flows, now S of Bull Creek canyon, form the W and SW margin of Chalk Basin. This platform is asymmetric across Bull Creek canyon, with the S bank breaking over at about 3940’, and the N bank breaking over rather higher at 4060’. Is the end of the “younger” flows pinned to a lower(younger) base level? The platform slopes to the S another 4 miles, ending in a S-facing scarp just N of Ryegrass Creek. There these lava flows are asymmetric across Ryegrass Creek, with the 144ka Saddle Butte lava flows on the lower S side. These flows also shoal against a SW-NE ridge of older topography located just N of Ryegrass Creek, and just W opposite Lambert Rocks.

Lastly, the topography just SE of Saddle Butte catches my eye. Are these Saddle Butte flows forming the prominent SE-facing scarp N of the Saddle Butte lava field? Or, is there a younger shield, broadly centered in the SW corner of Sect. 17, T29S, R40E. I hope the air photos will help me decide, because in Google or Bing satellite images it is not clear. I believe that Saddle Butte is composed of somewhat evolved lava flows and not actually basaltic. Perhaps we can tell just from hand specimen where these flows come from.

Sacramento Butte

The topography of this butte also catches my eye. It forms a prominent W-facing scarp, framing the E side of the Barren Valley. We drive partly over its surface on the way to Rinehart Ranch. It did not strike me as particularly young, but it did not seem as old as Deer Butte either. While its source vent is clear, the topography N and E of that vent suggests either significant erosion, or that another unnamed vent area is 2 miles ENE of the vent. Are these “two” vents allied in time? That “vent” forms scarps with breakovers at and above 4300’. While high, this is still lower in elevation than Deer Butte, which is only 4Ma old. Is this vent younger? Sacramento Butte’s W-facing scarp breaks over about 4160’; does this mean it’s younger, or was this just the sort of relief on the “upland” surface? I am curious about these volcanoes. They are probably older, but perhaps by not that much.

W of Iron Mountain

Several shield volcanoes in the vicinity of Iron Mountain may be rather young. Farthest W is vent 4838’ which is located at the W side of the kipuka within the 144 ka Saddle Butte lava flows that we cross on Hwy 78. Bill Hart may have an argon experiment on these lava flows. These flows move SE and end in the area of Palomino Lake. The relief of this flow field surface strikes me as rather young.

Another vent, called vent 4257’ in the SE corner of the Palomino Lake quad, is perhaps a major source of “young” lava flows. It passes N of Iron Mountain, and bifurcates into two E directed arms around some old topography. The northern arm seems to end on a broad E slope to the S of a minor flow projecting E out of the Saddle Butte lava field. The southern arm continues E well past Iron Mountain, into the Owyhee Butte quad where I fear it hides under thin sediments, possibly all the way to the present course of the river. This southern arm has N-facing and E-facing scarps that break over at about 3840’ that both seem to die out as they pass into the Owyhee Butte quad. Again, are they masked by sediments, or do the flows pinch out?

Another arm of flows from vent 4257’ passes W and S of Iron Mountain, with Palomino Creek probably forming its SW margin, going all the way to Burns Junction. This arm bifurcates around Scott Butte, passing eastward between Scott Butte and Iron Mountain, ending at an E-facing scarp the breaks over at about 3840’. Isn’t that interesting? SE of Burns Junction, the flows go some distance down Drought Creek, and pass E past Burns Junction, probably ending in some odd topography where Palomino Creek dumps over a broad E-facing scarp. Some maps put a N-S fault through this topography. In any case, vent 4257’ is a bit of a brute.

Iron Mountain itself, may be a relatively young basalt shield, though it seems clearly stratigraphically older than the vent 4257’ lava flows. Lava flows from the vent move SE, and end at an E-facing scarp that breaks over at the same elevation as the vent 4257’ lava flows N and S of it have. Can you say “Graded to the same level?” Perhaps Iron Mountain and vent 4257’ are part of a single time episode, with two vents; first Iron Mountain, then vent 4257’.

A vent called “Dome”, in the Palomino Lake quad, which is almost nested within the Saddle Butte lava field, may or may not be a young vent. It probably bears some inspection on the ground, and at least a single paleomagnetic site. Hart also believes that Scott Butte is about 1Ma in age. Morphologically, I can believe this, but I want to see the air photos, and eyeball it from the ground also.

In the Rome quad, Bill Hart has generated two K-Ar ages on flows on the W bank of Crooked Creek. I thought these were within the State Wayside Park, but they are actually several miles N of there. He found an age of 0.91 ± 0.36 Ma on the “rim HAOT” and an age of 1.25 ± 0.28 Ma on the “lowest exposed flow” about 30m lower in elevation. Although both these experiments need to be replaced with 40/39 work, these experiments say these scarps are 1-2 Ma in age, and NOT 3-4 Ma in age. The upper date seems to be in flows from vent 4257’. Lower age is less clear. Some topography, E of Scott Butte, may be a local basaltic vent. It seems to be embayed by the vent 4257’ lava flows, but could be the source of the lower ledge. DRILL THEM ALL! And let God sort them out!

Why should you care? – We evidently have at least two young flow fields moving eastward and ending in E-facing scarps, possibly interacting with the Owyhee River. We should frame them stratigraphically, get better ages, and look at the stratigraphy they hold down and hold up. Might they have a pillowed margin, or some fragmental character? “Young” very clearly comes from the W and gets to, or gets near the Owyhee River.

S of Hwy 95

There are a couple of basalt lava fields to the S of Hwy 95 that catch my eye, but the flows from Jackies Butte, may be the only lavas that have interacted with “lakes” in the Rome basin. A smaller, and probably older vent, SE of Burns Junction may also be of interest. These flows are just E of Anderson Reservoir, so I call them the Anderson Reservoir vent. Crooked Creek is W of these flows, Rattlesnake Creek is E of them, and Drought Creek flows SSE before joining Crooked Creek and flowing NE through a funny little canyon cut across older terrain. George Walker mapped the young flows from vent 4257’ as flowing SE, down Drought Creek almost to its join with Crooked Creek. I am going to check if this is correct. Perhaps the vent 4257’ flows are the reason that Drought Creek turns abruptly S, from a former course to the NE, perhaps joining Palomino Creek S of Scott Butte.

The Anderson Reservoir flows seem heavily mantled by sediments, possibly suggesting greater age. And, no “vent” construct is easily visable either. But, I recall that Crooked Creek has glacial breakout floods from the Steens country, and perhaps they have carried enough sediment to prematurely age these flows. The eastern scarp of this flow field, where it can be seen, breaks over at about 3840’, and perhaps that means something to us.

The Jackies Butte flows have been K-Ar dated by Bill Hart at 0.36 ± 0.13 Ma at a site farther SE along Rattlesnake Creek. The age strikes me as a tad young, but again, it is not a 3 or 4 Ma flow field. If it is this young it should have normal polarity. Jackies Butte lava flows form a prominent N-facing scarp at the S end of the Rome basin. It breaks over at about 3890’, but may be relatively thin flow on a more than 100’ scarp mostly in sediments. We should inspect this margin to look for evidences of water-lava interaction. The scarp ends to the E in the vicinity of Rockhouse Reservoir.

Lastly, the basalt shield of Water Hole Butte may be of interest. It may be as old as Deer Butte, or even older. It backs SE onto even older topography, and abuts Jackies Butte over a more than 6 mile saddle between them. Its western flank is faulted rather severely which may be telling us something about its age. One of the fault traces cuts across the contact with Jackies Butte and breaks those lavas too. It is unlikely that this flow field interacts with the Owyhee River, and it may be one of the “upland” basalt volcanoes that preceed the downcutting witnessed over the past 4 Ma.

Why should you care? – I think clearly that Jackies Butte, and possibly the Anderson Reservoir vent have something to tell us about Owyhee downcutting and how Crooked Creek has adjusted to that arena. One of Kyle’s shoreline maps laps against the N scarp of Jackies Butte.

SE of Rome

A young flow field, on the E side of the Owyhee River may also help us understand the River’s history. The surface of the rim behind where we put into the Owyhee River is covered by flows from Round Mountain, which is about 5 miles off to the SE. Bill Hart has a K-Ar age of 1.49 ± 0.18 Ma on an outcrop of this lava flow field. This age needs to be replaced, but again these flows are no older than 2 Ma, from the age work in hand. These flows shoal northward against some older terrain (4 Ma (?)), that I think I sampled at the top of the grade before you drop down to the Owyhee bridge on Hwy 95. They also infill block-faulted terrain to the SE, having an edge that is difficult to pick up from Google or Bing. The elevation of the W rim of this flow field does not seem very constant. It is as low as 3700’ above the put-in, and climbs southeastward to almost 3900’ up river. It evidently is mantling sloping topography, and doesn’t seem to be “lake bound” in any easy way.

Why should you care? – The edge of this young flow field determines the course of the Owyhee River over a distance of 8 to 9 miles. Parts of this flow field are on the SW side of the river, meaning that this flow might have filled and buried the former canyon of the Owyhee River. Should we be looking for a filled channel in the eastern wall of the Owyhee S of the put-in park? Will we find evidences of lava-water interactions along its western margin? We should investigate this young flow.

You want lava, landslides, inverted topography, lava-water interaction, and more?

2010-04-07T17:36:00.000-07:00

Maybe a trip to this part of southern Argentina is in order. Check this out:

Visit this area here: http://www.flashearth.com/?lat=-48.224343&lon=-70.821068&z=11.6&r=0&src=msa

Draft version: Major volcanic vents in the Owyhee field area (east sector)

2010-03-31T09:17:00.001-07:00

Here is a map for the research group to review. This includes several sites mentioned in the paleomag update recently posted on Yeehow Central. Review it for naming conventions, placement, etc. Note also the addition of Danner Butte...an informal name for a likely vent associated with a youngish flow. Previously the lava related to that vent was grouped with that from Rocky/Lava Butte, but this was not feasible as it required a lot of lava to flow a long way uphill. The boundary between the two is not shown on this map, but I am working on it (Note: N. Bondre identified this vent as SH, but I have forgotten why...looking into that too). Now I know: Skinner Hill.

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Summer, 2009 Paleomagnetic Studies

2010-03-30T14:22:00.000-07:00

During the summer of 2009 we made some progress using paleomagnetic field studies to better illustrate what volcanic units and events we have in the Owyhee River country, and which ones should have better (or any for that matter!) age control. I will describe the volcanic units in order of increasing age, each followed by thoughts on what I might sample this next summer. Feedback from you all re: what I should, or should not do, are welcome. The equal area plot that Kyle put up earlier can be viewed while reading what’s below.

West Crater lava field – from previous years we already had 6 sites, but we added one more taken near Lava Sink Reservoir, on the upper W flank of the flow field. We never really had a site that was undeniably “in” West Crater flows, and this site solves that small aspect. It averages with the previous sites quite adequately.

What’s Next? – adding a site to the NW, in the SW corner of Sect. 33 where Kyle and Cooper tell me that West Crater flows thin against what was originally the W side of the Owyhee.

Saddle Butte lava field – we didn’t add any new sites. Never got on that side of the river.

What’s Next? – in the averaging of the 6 sites we have in this unit, I leave out the two sites we did on the river trip at Sand Springs Camp (in “old” Saddle Butte), and at river km 38.75. For different reasons I fear they are not my best work. I want to replace these two sites by driving and walking over to the river from the W. I also want to add a site in E Granite Creek to better sample “old” Saddle Butte, to see if it has discernibly different magnetic directions than “young” Saddle Butte.

Forgotten Butte (vent 4526’) – this was one time thought to be a rootless vent of Clarks Butte. We added three sites that make it clear now that it is different in magnetic direction, and younger stratigraphically. A site located just N of Bogus Lake, and another located between where the young West Crater lavas and Lava Butte (sometimes known as Rocky Butte) lavas almost touch agree with sites in Forgotten Butte, and not with Clarks Butte. Because the center of Bogus Creek valley is a patch of higher standing older flows this means Clarks Butte is covered by these flows in the area. Forgotten Crater is therefore younger. We know Clarks Butte flows go W through this valley, because we have the terraces downriver. We have no evidence in hand that Forgotten Crater makes it to the Owyhee River, but we should keep our eyes open.

What’s Next? – adding a site along a W to E road which ends at Dry Lake Reservoir, to the NW of Lava Butte. I have a N-S contact drawn on the topo map separating Forgotten and Clarks Buttes, and it ends at about Dry Lake Reservoir. I want to prove it out.

Clarks Butte lava field – we added a new site along the N part of the field, just S from the Jordan Craters flows. It was rather badly struck by lightning, and didn’t clean up very well. Alas! We have 4 sites in good agreement with one another.

What’s Next? – adding a site along the S margin of the field near Dry Lake Reservoir as described above. Also, sampling the rectolinear “uplifted” outcrop, parallel to and directly below Bogus Point. I’m betting this is Clarks Butte. There are several “old” bulgey outcrops which protrude up from the floor of Bogus Creek valley. Are these Clarks Butte, or just West Crater flows with a bit of inflated “attitude”? Or are they Forgotten Butte?Also, we have an argon age experiment in play for this unit. Age by June!!

Greeley Bar lava field – we added two more sites to this unit. They average together pretty well with earlier work, and while the mean remanent direction is similar to Deer Park they are arguably slightly different.

What’s Next? – adding one more site up top to the NW near Riley Horn Reservoir where Greeley Bar overlaps the old shield volcano which has collapsed northward into the Hole in the Ground. Also, getting down onto the Greeley Bar bench and sampling whatever units we can find there, that we can sample (I mean actually stand next to and drill), and get the sun to shine on the sun compass. Not too much to ask, is it? We have an argon experiment in play for this unit, data by June, we hope.

Deer Park vent – we took our first two sites in this unit. An ordinary sort of reversed direction is found, that is similar, but perhaps not the same as Greeley Bar. The two units can be petrographically differentiated in the field; Greeley Bar is quite phyric in plagioclase, while Deer Park is more aphanitic. Deer Park underlies Greeley Bar; it made a dam across the Owyhee River first, perhaps numerous decades earlier. Does anything we have seen from above, or from river level confirm that Greeley Bar flows into a lake not of its own making?

What’s Next? – adding another site at the N base of the Deer Park lava cascade, just above where it turns into a cliff. Will it have the same petrography? Will it have the same direction?

Owyhee Butte – we took our first three sites in this unit. We found normal polarity, so these flows cannot correlate to Bogus Point, as originally mapped. The 1.86± argon age is within the Olduvai Normal Polarity Subchron so our age work seems valid. Owyhee Butte flows W forming a lava delta seen from the rim and from river level. The topographic continuation of the transition between subaerial lava, and subaqueous pillows and fragmental basalt seems to be just below 3800’ elevations. You can follow it SE to Eiguren Reservoir #2, and NE to near the bend in White Rock Creek. To the W Owyhee Butte seems to overlie reversed polarity Bogus Point lava flows, and reversed polarity Little Owyhee Butte lava flows. There is a fair possibility that yet another (older?) basalt underlies Owyhee Butte between Bogus Point and Little Owyhee Butte. It would be the E rim of the Owyhee canyon from about the falls of While Rock Creek to the latitude of Eiguren Reservoir #1. Owyhee Butte crowds S onto Little Owyhee Butte and deflects W and SE from that topography, and possibly makes it all the way to the N side of Jordan Creek W of Arock. Where Owyhee Butte lavas rim the W side of Hidden Valley they form a scarp not dissimilar in elevation to the scarp formed to the W. I don’t know if any of this margin has pillows and fragmental outcrops, but does this possibly mean that Owyhee Butte was flowing eastward into standing water also? Or just across relatively dry mud flats?

What’s Next? – adding two sites on the E side of Owyhee Butte, NE and SE and investigating the nature of the eastern rim above Hidden Valley. Any evidence of water interaction? Also add a site just E of the main N-S road, and E of Eiguren Reservoir #2. SW margin of Owyhee Butte loses simple topographic expression; do flows make it to the Owyhee River Rim?

Arock summit volcano – we took a site at the summit of the Arock shield. I had loudly trumpeted last Spring that it was the vent for the Bogus Point lava flows. WRONG!!!! It has ordinary normal polarity, and thus can’t correlate. I loosely imagine these flows to be Olduvai in age, but without much conviction; they could be much older. I believe the Bogus Point lavas come out from under this shield. The Arock lavas seem to encroaching southward onto an older vent I am calling the Juniper Tree Reservoir vent, which is just N of the Merrill Springs Rim. It is this vent that is my current best guess as the source of Bogus Point flows. But we already know how good my guesses are!

What’s Next? – finding where the margins of this volcano are. I will take on site on its NW margin in the ephemeral drainage next to West Crater, probably at about the 3900 to 4000’ elevation level. I will also take a site up NE from the road through White Rock Creek valley, probably again at about the 4000’ elevation level. Lastly, I will take a site or 2 E and SE of Bogus Creek Well. Only a poor, possible topographic signature of the W edge of Arock lavas exists. Do those flow lap onto the gravels at and N of Bogus Creek Well, or are they more likely lapped by the gravels?

Little Owyhee Butte – we took 6 sites from lava flows from this vent. It has an ordinary reversed polarity magnetization. They group adequately, but better when I exclude the site done on the main road coming up from the bridge (possibly rotated southward at edge of rim), and a site done NW of Eiguren Reservoir #1, that may be in a different, older(?) unit. The K/Ar age for this vent is near identical to Owyhee Butte at 1.87± Ma, and must be too young, and at least 1.94 Ma in age, the age of the onset of the Olduvai Subchron. At a site we did above the rim of Jordan Creek that I call the “gooseneck” we saw a glorious expanse of subaerial lava flows over a southward directed pillow sequence. The transition of subaerial to subaqueous is at or below 3700’ there. Cooper says pillows exist at the SW margin of Little Owyhee Butte flows where they rim the Owyhee River opposite where Crooked Creek joins the Owyhee. They would also seem to transition, at or below 3700’. We need to get some real measurements of these elevations!

What’s Next? – we already have a good population of sites. I will add one at the small “vent” located where the main road splits from the road to Owyhee Butte. I am guessing it is a Little Owyhee Butte “rootless” vent, but I am (0 for 1) on those guesses. I will also investigate the W side of this flow field, as it rims the Owyhee River. Is it lapping onto another reversed polarity flow from another source?

Threemile Hill lava field – we have one site in this shield, and didn’t add any last summer. Its’ argon age of 1.86± Ma again has to be incorrect, and probably too young because the flow has reversed polarity. This volcano seems a long way from the river. But, it is relatively young and may be part of an episode of volcanism that includes other shields which do interact with the Owyhee River and “lake”.

What’s Next? – adding a site at the far N end of this shield volcano.

Bogus Rim lava field – we added 4 sites within this field, and they average together fairly well. The argon age for this flow at 1.92± is nearly correct, considering the uncertainty level. Our final new site was at the rim in Rinehart Ranch, so we have paleomagnetic confirmation the flows go at least that far. Bogus Rim seems to be the nth player of a sequence of big flows, and we need to know how much time they all take. Restated, the Owyhee River had done a fair job of downcutting by (??) Ma, and a sequence of basalt flows and sediments, ending with Bogus Rim, lifted the rivers base level and said “please start again!”. How long did that take?

What’s Next? – adding numerous new sites including; S side of river opposite Rinehart Ranch mesa, drilling whatever can be reached on the NE side of Jackson Hole (top flow must be Bogus Rim), near Cave Reservoir in Mud Creek, near lower Fort Creek Reservoir, just W of the “other” Cave Reservoir in the middle of Bogus Rim, and finally the outcrops perched above Birch Creek Ranch. We should submit our own argon sample for this unit; it is too important stratigraphically to us to leave our age understanding where it is now.

Middle “gray” flow @ Rinehart Ranch – we took a site in the so called “middle” flow of the rim at Rinehart Ranch. In the gigapan that Kyle posted of that outcrop you can see Kevin Geipel, my field assistant, and I leaving that site. It has an ordinary reversed magnetic polarity, that turns out to be quite similar to the overlying Bogus Rim direction. I could interpret the directional proximity to mean time proximity of only a few decades or so. But, we believe the direction similarity is a coincidence, as the colluvial wedge, with capping soil that separates them must have taken 1000’s of years or more to form, plenty of time for the geomagnetic field to go wherever it wanted to go (maybe several times!), and then come back. But it does mean that an earlier stratigraphic unit than the Bogus Rim lava, has a magnetic direction difficult to tell it from. The “gray” aspect of that flow arises from the profusion of plagioclase in the basalt; hopefully that aspect will stay systematic and assist differentiation.

What’s Next? – when we are on the NE side of Jackson Hole, I hope to run into this plag-phyric flow under the Bogus Rim lava flows there. At Iron Point, Kyle and I could look down to a lighter gray outcrop, with rounded corners bounding joint surfaces, that I think might be the middle “gray” flow. Also, on the W side of the Owyhee River are outcrops of Bogus Rim, underlain by something else. Kyle was showing Cooper and I pictures from the upper parts of Jackson Creek of these two units. Sites could be located in these units if the logistics of getting there isn’t too adverse. We have an argon experiment in play for this unit. By inference it will suggest what a good age for Bogus Rim should be also.

shield volcano under Arock – Bogus Point lava flows – we added three sites to this unit. They average together well, having yet another ordinary direction of reversed polarity. I estimate the age of this unit to be 2.1±0.2 Ma, but without a lot of conviction; it could be rather older. A unit just to the E, that Ninad Bondre called “Bernie’s Bench”has an age of 2.8Ma, and that might be the appropriate age frame to be thinking of. This unit is in for an argon age date, and that is very important. We need to figure out from which vent this unit comes from.

What’s Next? – numerous additional sites to be taken. An area I am calling the Juniper Tree Reservoir vent, may be the source of the Bogus Point lava flows. It seems to be under the Arock shield. Also to their S, the Merrill Springs Rim may be Bogus Point in character. We also want to sample the unit under Owyhee Butte lava flows 2 mi NW of Eiguren Reservoir #2 to see if they are still Bogus Point, or some other unit. Lastly, we want to sample the basalt ledge on the N side of Bogus Creek, under the white sediments, under Bogus Rim. These almost have to still be Bogus Point lava flows, but we want to make absolutely sure.

“Tertiary” basalt above Rome – we took a single site along Hwy 95, just E of the Owyhee River, where the road begins its steep descent to cross the bridge over the river. The rock was coarsely diktytaxitic, oxidized, and looked more than a bit tired, so I am guessing an age of about 4 Ma for it. It has a rather odd reversed polarity magnetic direction, but needs other sites to confirm this is not an outcrop stability issue. This all may be important with regard to several vents in the Rome basin area, which have 30-year-old K-Ar ages between 1 and 2 Ma that Bill Hart and others generated. These experiments all need to be replaced, but they still likely provide quality age inferences. These “young” basalts may well have interacted with the Owyhee “lake” post-Bogus Rim time, possibly for numerous 100,000’s of years. I will be sending another letter regarding this idea/opportunity. To the E and SE of Rome is one of these “young” basalts which seems to vent from Round Mountain, in the Scott Reservoir quad. These flows are really topographically above the Rome basin, but the present course of the Owyhee River is determined largely by the southern and western margin of this flow field. The western rim of this field above the Owyhee River seems to be relatively horizontal and just below 3700’, which is within the basin.

What’s Next? – adding sites to confirm that the site I took IS in older basalt flows, and that “young” Round Mountain flows lap northward against them before being deflected NE toward Dry Creek, and W toward the area just S of the Owyhee River bridge. And, some sort of inspection of the edge of Round Mountain flows should be conducted. Can we see evidence of flowing into standing water? Interaction with flowing water? Did these lava flows fill the preexisting canyon of the Owyhee, and move it S and W? By its’ morphology, Round Mountain is a fairly young volcano, so its’ impact on the Owyhee River is really quite recent. More on this topic later.

Is there anybody out there?

2010-03-24T20:41:00.000-07:00

Wow. It seems like the Owyhee enthusiasm has really waned since we are not planning a river trip. However, please note that I have been doing a final pass through the map to fine-tune the mapping and ensure that every line and poly are attributed. I will also be working on the one-pager and the long profile in the near future. Made major progress a few weeks back, but my other maps intervened. Stay tuned.

Paleomagic Results

2010-03-08T18:20:00.000-08:00

Duane has been working as hard as ever on the paleomag samples collected in our general study area during the last field season. As he notes, this intriguing plot is notable for:

Clarks Butte and Forgotten Crater difference
West Crater and Saddle Butte still not the same
Bogus Rim and Middle Gray flow similarity
Greeley Bar and Deer Park similar, but possibly differentiable.

Also of interest is which flows are reversed and which are not. Duane has also uncovered some intriguing dates from nearby that have been reported in a variety of studies. More on that later.

The 1160 m spillway of the Bogus Rim lava dam.

2010-03-08T13:22:00.001-08:00

The 1160 m elevation is a plausible call for the 1.8 Ma Bogus Rim lava
dam on the Owyhee River, OR. Consider these points:

1. It does not generate a lake that laps on to western margin of the
subaerial part of the Bogus Rim lava flow upstream.

2. It coincides with the downstream edge of the upstream-most couplet
of Bogus Rim lava remnants on both sides of the gorge below Iron
Point.

3. It is the elevation of the first unequivocal gravel outcrop on the
surface of the Bogus Rim lava flow in the gorge.

Issue: The highest pea gravel clast(s) I can find on the outer edge of
the Bogus Rim flow occur at 1205 m. An exceedingly sparse array of pea
gravel admittedly, but pea gravel nonetheless.

Posted via email from Fresh Geologic Froth

More on the recent landslide in Italy. (2 additional minutes)

2010-02-16T15:06:00.001-08:00

Fa-freaking-nomenal

2010-02-16T14:49:00.001-08:00

Cool Rio Grande Landslide Paper

2010-02-12T14:21:00.000-08:00

Alright, bear with me. This is my first post to the blog, but I found this awesome paper on landslide dams on the Rio Grande River.
I had not come across it yet in all my searching for every lava and landslide dam on the planet. Some of you may have seen it and

some of you may have not, but all should enjoy!

Here is the link: The paper

Familiar Places?

2010-01-25T11:30:00.000-08:00

I was checking out the coverage in Google Street View the other day and happened upon these.

Continuing concerns about the landslide dam at Attabad in Hunza, Pakistan

2010-01-25T09:53:00.000-08:00

Note: This is from Dave's Landslide Blog.

Continuing concerns about the landslide dam at Attabad in Hunza, Pakistan: "The Pamir Times continues to provide excellent coverage of the state of the landslide dam at Attabad in Hunza, N. Pakistan (see earlier posts here, here, here and here). First, they have posted another remarkable image of the landslide in action:

Second they have provided various reports on the state of the efforts to mitigate the rising water level and to reopen the highway. It is clear that the road remains blocked, which must be creating incredible hardship in the valley upstream of the slide. It appears that the Chinese engineers who are planning to reopen the road have only just arrived on site. Promisingly, the report states that another group of Chinese engineers have arrived to attempt to drain the lake, presumably working with the Pakistan Army. One can only hope that these are the same group that performed extraordinary Tangjiashan barrier lake drainage operation.

The magnitude of the task is well-illustrated by this report, also from the Pamir Times. The lake is now 8.9 metres long and is filling at a rate of about 3.6 feet (1.1 metres) per day. The Pakistan Army has promised to release the water within 45 days. The images show the nature of the problem even more clearly. This image, taken from a helicopter, shows the landslide dam deposit:

It is clear that the the lake is now rising quite rapidly towards the natural spillway. This image shows the size of the lake itself:

It is clear that the water is now starting to encroach onto farmland in a serious way. Finally, this image shows the state of the lake on the ground:

If you are one of the few that view my Geologic Frothings Blog. Please note that the newest manifestation resides at http://geofroth.org.

2010-01-21T10:28:00.001-08:00

Posted via web from Fresh Geologic Froth

Owyhee River LiDAR drape on low-res Google Earth images

2009-12-09T14:43:00.001-08:00

Ok. So Google is apparently never going to upload the high-res NAIP
imagery of the Owyhee River study area. Here is a work-around. Draping
the LiDAR on the bad imagery. Looks pretty damn good. Now we are very
proficient at doing this. On our way to developing some more elaborate
geologic projects in Google Earth. Should probably start with adding the hi-res imagery ourselves....

Thanks to Heather...she made it to the LiDAR class in San Diego last week!

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Killer Owyhee Pic of the Week #2

2009-11-22T21:10:00.000-08:00

A nice oblique shot of the Saddle Butte and West Crater lava convergence zone. Lots of important features are clear in this one. Look for your favorite!

New and Improved Profile figure and other...

2009-11-13T17:33:00.000-08:00

Ignore the mixed units and bask in the glory of a better long-profile:

Today, I learned some very cool techniques for extracting key data from the LiDAR as well as for analyzing and displaying the results in Arc. I had never experimented with the graphing tools in Arc, but Natalia showed me some really interesting applications of them while we rode the train from Portland to Eugene.

I suspect that some of you may be in the know, but I put together an explanation of sorts that includes some interesting data from the Owyhee here:

http://geologicfroth.wordpress.com/2009/11/13/turns-out-that-graphs-in-arcgis-are-pretty-damn-handy/

I didn't finish the lava profiles, but got a good start today. In the field all next week down in Vegas worrying about a different project. Back on Owyhee when I return.

Lyell was a closeted catastrophist?

2009-11-13T09:23:00.001-08:00

A recent (re?)-discovery by fellow Yeehow JEO:

Not so fresh geofroth, but insightful nevertheless:

Our historical figure states thusly...

"The power which running water may exert, in the lapse of ages, in widening and deepening a valley, does not so much depend on the volume and velocity of the stream usually flowing in it, as on the number and magnitude of the obstructions which have, at different periods, opposed its free passage."

which follows upon...

"It is evident, therefore, that when we are speculating on the excavating force which running water may have exerted in a particular valley, the most important question is not the volume of the existing stream, nor the present levels of the river-channel, nor the size of the gravel, but the probability of a a succession of floods, at some period since the time when some of the land in question may have been first elevated..."

Who is our extrafluvial catastrophist?

None other than Charles Lyell!

Lyell, C., 1830, The Principles of Geology, vol. i. John Murray, London.
The first quote is from page 192, and refers directly to floods resulting from breached obstructions as key to forming valleys. The second quote is from page 188.

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Sweet Owyhee Pic of the Week

2009-11-12T17:41:00.000-08:00

A nearly complete shot of the East Spring (Greeley) landslide. Yowza.

Short clip of the Owyhee fly-over...

2009-11-05T22:59:00.001-08:00

Worth a look. Gives a good impression of what the flight was like. Certainly quicker than a raft.

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Slide Show from Today's Owyhee Fly-over

2009-11-04T20:46:00.000-08:00

As promised, here are the pictures. If you would rather seem them on the Picasa site, you can go there with this link:

http://picasaweb.google.com/drjerque/OwyheeFlyOver?feat=directlink

Once there, choose view on map, or grab the kml link for a better overall experience. Note however, that the geotagging is locally off...I wasn't totally prepared to deal with a tracklog derived from a trip in a vehicle that was usually moving more than 150 mph or so. In that case, the clocks need to be tightly calibrated (to the second) and the track precision needs to be high. I will manually fix the egregious ones using the new and nifty interactive geotagging interface in Picasa.

An amazing day in the field...

2009-11-04T20:10:00.000-08:00

Today, I had the opportunity to fly over our field area in a spiffy little experimental aircraft with my UNR colleague, Greg Arehart. Greg built the plane and is an accomplished pilot. It was an excellent time. From Reno, it takes less than two hours to reach the Owyhee in his plane. Once there, we followed an improvised flight plan driven largely by my whims and Greg's skills at maneuvering an aircraft. The map below shows the path:

It was mind-bending to be able to see the field area from this vantage. I took around 200 photos from the cockpit. Below is a very nice example. Note that it was a beautiful day to be in the field.

Best of all is the underwing camera that Greg installed on the plane. It is controlled by a laptop computer in the cockpit and takes absolutely amazing vertical air photos with overlap adequate for stereo viewing. The image below should suffice to prove that. I took 190 of these photos.

All of the photos will be posted or otherwise made available soon!

Will be visiting the field area tomorrow...in a plane!

2009-11-03T20:58:00.001-08:00

Tomorrow I get a chance to fly over the field area in a small plane
fitted with an underwing camera. This was part of the deal that got me
to agree to teach field camp this last summer...and it is finally
coming through. Greg Arehart, my UNR colleague, has offered to fly me
over the area and snap many, many photos with his spiffy camera. These
will be ideal for creating large scale stereopairs of key areas
(failed blockages, landslide dams, etc) and also many great oblique
shots.

Below are some photos Greg took while flying over the field camp site in June.

See the full gallery on posterous

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Flash Earth and Geohacks...Who knew? Not me.

2009-11-03T05:43:00.001-08:00

Just happened upon a sweet and simple geobrowser called Flash Earth...very smooth and easy to understand. Added bonus for me is that it links to high-res images of my favorite field area that are available only in Yahoo and Bing Maps:

Seems my pals at Google still just don't care about SE Oregon. Anyway, I found the site by perusing the details in an exif header in one of my geotagged photos. Was checking that out in Irfan View, a program I was aware of but hadn't tried yet. Turns out, it is well worth a look:

Which led me to the GeoHack wiki:

The internets are amazing, no? Totally cool.

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Croall et al. Poster from GSA

2009-10-28T11:40:00.000-07:00

SR 410 Nile Valley Landslide (west of Naches)

2009-10-28T11:13:00.001-07:00

SR 410 Nile Valley Landslide (west of Naches), originally uploaded by Washington State Dept of Transportation.

An excellent view of the landslide...nicely done.

SR 410 Nile Valley Landslide (west of Naches)

2009-10-28T11:06:00.001-07:00

SR 410 Nile Valley Landslide (west of Naches), originally uploaded by Washington State Dept of Transportation.

Check out the great photoset of the recent landslide near Naches, Washington.

http://www.flickr.com/photos/wsdot/sets/72157622438776353/

Impressive lava-river interaction in Argentina

2009-10-24T18:11:00.001-07:00

Some images from Google Earth and Google Maps of an area of significant lava and river interaction in Argentina. Field Trip! The center of the image is approximately 36.40 S, 69.42 W.

This site was discussed in the following talk:

GEOMORPHIC HISTORY OF RIVERS DRAINING THE EASTERN ANDEAN CORDILLERA (34–37°S) CONSTRAINED BY TEPHROCHRONOLOGY, U-SERIES DATING OF PEDOGENIC CARBONATE AND COSMOGENIC ³HE DATING OF BASALT FLOWS

HYNEK, Scott A., Geology and Geophysics, University of Utah, 115 S 1460 E, Salt Lake City, UT 84112-0119, scott.hynek@utah.edu, MARCHETTI, David W., Geology Program, Western State College of Colorado, 600 N. Adams St, Gunnison, CO 81231, FERNANDEZ, Diego P., Geology and Geophysics, University of Utah, 115 S. 1460 E. Rm 383, Salt Lake City, UT 84112, and CERLING, Thure E., Department of Geology and Geophysics, University of Utah, Salt Lake City, UT 84112Alluvial deposits and associated geomorphic features are dated by their relation with volcanic rocks. The age range and geologic setting requires a broad approach to constraining the history of rivers draining the Cordillera. Maximum age estimates are provided by identification of the ~ 450 ka Diamante Tuff in fill terraces. Along the Río Diamante this ash bed is observed >100 m above modern river level. In the Río Papagayos and Río Atuel drainages, the Diamante Tuff is associated with alluvial surfaces much closer to modern river level. Coarse Diamante pumice in the Río Atuel implies significant changes to the headwater drainage system since 450 ka. The maximum age constraint implied by occurrence of the Diamante Tuff in fill terraces has been successfully combined with minimum age estimates from cosmogenic ¹⁰Be approaching 350 ka (Baker et al., 2009). The relatively old age of alluvial surfaces in the region is additionally supported by U-series age estimates derived from pedogenic carbonate in volcanic soils. A minimum age in excess of 100 ka is conservative. The dated surface is underlain by a pumice/lapilli tephra deposit and basalt flows both of which have the potential to provide maximum age estimates for the surface. Conversely, the U-series data implies that the basaltic volcanism is older than 100 ka. Our age estimates of flows in several drainages are much younger. Cosmogenic ³He concentrations in hornblende from basaltic-andesites erupted along the Río Salado indicate exposure, and therefore eruption, ages younger than ~ 6 ka. These flows temporarily dammed the Río Salado in one location and bedrock incision below the level of the flows has occurred since. ³He concentrations in olivine from basaltic rocks at northeastern Volcán Payún Matru indicate a shield-building phase at ~ 40 ka. Recent basaltic aa flows from multiple vents are morphologically quite young and ³He exposure ages are forthcoming for one of them. The Río Grande has incised the older flows, and provides an average incision rate over a full glacial cycle. Combination of geochronological data from the region indicates provides accurate, if not tightly constrained, ages for alluvial surfaces and identifies spatially variable geomorphic rates influenced, in part, by contemporaneous volcanism.

See the full gallery on posterous

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Lava v. River example from British Columbia

2009-10-24T16:11:00.001-07:00

Kathy C. turned me on to this example yesterday. I had no idea. Lava flow is only about 250 yrs old. It is in the Stikine Volcanic Field. There is a related, somewhat brief, paper:

Roberts, M.C. and McCuaig, S.J., 2001, Geomorphic responses to the sudden blocking of a fluvial system: Aiyansh lava flow, northwest British Columbia. The Canadian Geographer, v. 45, n. 2, p. 319-323.

The vent is located at 55.11 N, 128.89 W.

Field trip!

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Submerged tree in Clear Lake, Oregon

2009-10-22T23:11:00.001-07:00

This underwater picture shows a lone submerged tree in Clear Lake, OR.
There are many more than this. One (maybe most) date to about 2700 yrs
bp when a lava dam blocked the McKenzie River. Freezing water,
exceptionally clear.

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Intracanyon lava flows: Does the river give a dam?

2009-10-21T12:45:00.001-07:00

Check out this SlideShare Presentation:

Intracanyon lava flows: Does the river give a dam?

View more presentations from Kyle House.

Owyhee lava and river profiles: location

2009-10-16T14:34:00.001-07:00

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Owyhee lava and river profile figure...draft

2009-10-16T14:24:00.001-07:00

Finally devised a way to confidently and easily extract profile data from the LiDAR data set in GlobalMapper. Surface profiles are simple. Basal profiles shown here are estimates based on some point measurements. Will vastly improve the basal profiles when GSA is over. Needed this figure, however, so spent too much time devising the method.

Only issue now is to develop a technique for efficiently normalizing all the profiles to a reference thalweg of some sort. Already have data in xyz, so a quasi 3-D diagram would be the most realistic.

Need to talk about this with the group.

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Nice renditions of the Owyhee River area map

2009-10-14T16:23:00.001-07:00

Preparing for my GSA lava talk and came up with these new versions of
the map of the Owyhee River study area. The second one is just the lava.

See the full gallery on posterous

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The lava flow-landslide link laid bare

2009-10-14T16:22:00.001-07:00

This one supports the tenet:

'Intracanyon lava flows, the gifts that keep on giving'.

A garishly colored map that underscores the tight linkage between
landslides and lava flows on the Owyhee. If it is not the margin of
the lava flow that is failing, then it is the canyon wall that the
lava flow forced the river against that is failing (or both).
Certainly a tight coupling in this reach, no?

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Two pleasing renditions of the map

2009-10-14T16:15:00.001-07:00

Preparing for my GSA lava talk and came up with these new versions of
the map. The second one is just the lava.

See the full gallery on posterous

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Bogus Rim Lava / Iron Point Dam...beginner's edition

2009-10-14T14:19:00.001-07:00

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Bogus Rim Lava / Iron Point Dam

2009-10-14T13:47:00.001-07:00

An obvious, but overlooked addition to the Oywhee River lava-dammed lake story. This is the approximate extent of the early Pleistocene lake caused by a Bogus Rim lava dam crest of 1210 m at Iron Point.

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West Crater and Saddle Butte lava faceoff at Ryegrass Creek

2009-10-12T14:17:00.001-07:00

This upstream-looking 3-D block rendition of the Ryegrass Creek area on the Owyhee is intriguing. The color ramp works well here because the strata are flat-lying. Note the boulder-covered and very flat surface below the Qbsy and above Ryegrass Creek...I suspect it relates to the pre-Saddle Butte lava Owyhee or Ryegrass Ck channel in some way, but I have never actually stood on it. Also, look at the morphology of the eastern edge of the Qbsy where the lacustrine seds sit...distinct linear trace there was map as fault by Ferns et al., but isn't it just the contact between the paleovalley wall and the lava? What about that abrupt wall in the Qbsy flow just beyond there? Looks like it is heading down a narrow valley.

See the full gallery on posterous

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Some intriguing LiDAR-based block models from the Owyhee

2009-10-08T16:34:00.001-07:00

These images of the Owyhee River LiDAR data were made using Surfer 9. They are amazing.

See the full gallery on posterous

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State of the Owyhee Map: 10/01/09

2009-10-01T14:27:00.001-07:00

These images each depict a part of the Owyhee River map area at 1:50000. The various fluvial units are generalized somewhat because it is too hard to resolve them at this scale. I began working on the map in earnest back in August 2007 and it has come an extremely long way since then. A preliminary version was already complete by the time we got the LiDAR data in March of 2008. Since then, I have probably put more time in on revising the map in light of (pun, get it?) of the LiDAR data. I do not even want to tally the 100s of hours I have spent in the field and in the office working on this thing.

What is left:

1. I need to do a full pass through the entire map and fix the topology and the line attribution and final fine-tuning. I have already started this in the Hole in the Ground area.
2. Unit descriptions need to be written up using Cooper's thesis as a base. This part will require input from all principal members of the research team
3. Accompanying text to the map. This will be a detailed accounting of the geologic history implied / required by the geologic map.
4. Send the whole package out for review. Likely, we will do this through DOGAMI who have agreed to publish the map if we can cover most / all of the costs.

Now, back to the lower Walker River map due in 15 days.

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Geologic Map of the central Hole in the Ground area, Owyhee River, OR

2009-09-30T11:17:00.001-07:00

Screenshot that shows the current status of my mapping in a key area. Landslides are green and broken into three relative ages (brighter=younger). Red lines have not been attributed yet. Map is coming along nicely.

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Owyhee Mapping Project: All traverses by your pal, Kyle.

2009-09-29T22:06:00.001-07:00

Ok, so maybe I spent enough time out there in 2007, 2008, and 2009. Yikes. As expected, the parts of the map that are the hardest to compile in the office are those areas I never hit on the ground.

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My 2009 field traverses in the Owyhee River study area

2009-09-29T21:52:00.001-07:00

Yes. I am a little late on getting my NSF annual report done...why these are due 3 months before the end of the year in question is beyond me. Most annual reports are due within 3 months of the end of the contract year. I suspect that someone made a mistake in the original paperwork and simply won't own up to it.

Anyway, getting the report together has given me a chance to organize my field data more completely. Here are the traverses from this year. This includes the group trip in late May, my field camp stint in early June, and a solo trip in August.

The utterly obvious concept of making a traverse map is made very simple with a Garmin 60csx, the DNR Garmin (free) software, and ArcGIS. But, hey, you already knew that because you record all of your field traverses that way, right?

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LiDAR-derived contours are useful, too.

2009-09-29T17:45:00.001-07:00

Sure, I have gone on and on about the amazing visualizations you can get with some tweaking of LiDAR data; however, it turns out that a pretty basic representation is also quite useful...contours. Yes, contours. Sometimes smaller scale features remain somewhat ambiguous in hillshades or slopeshades, but high-res, short interval contours from the LiDAR data can eliminate most of the ambiguity. In this case, it is a tiny area that I have struggled with on the Owyhee River. Here, a large landslide entered from the north, shoved the river channel to the south, and the river eventually worked its way back to the north to some extent. The array of surficial deposits in the void that comprises the right hand side of the image south of the river record this sequence of events as well as subsequent sedimentation by tributary fans. The contours really highlight the fans, and in conjunction with discernible drainage patterns evident in the LiDAR, it is clear what is fan and what is river, right?

2-m Contours were generated in GlobalMapper and exported as shapefile to view in Arc.

Note, Ian Madin (at DOGAMI) gave me the tip on contours especially as they relate to resolving fan features. He was right...it works!

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Extent of lake caused by the Greeley Bar lava dam

2009-09-29T16:46:00.001-07:00

I created this lake by generating a contour from the LiDAR dataset at an elevation of 1046 m. GlobalMapper does this in about 1.5 minutes. Then, exported the vector as a shapefile, cut out the parts of the line that occur downstream from the dam, stitch the remaining loose ends, build a poly from the line and there it is.

This lake has an interesting topographic correspondence with the old landslides on the south side of the Hole in the Ground as well as the ancient fan remnants that come in from the north side. Don't forget that much of the topography you can see through the lake didn't exist at the time of the lava dam. The valley floor was probably formed on the Bogus Rim lava which forms the flat-topped features that flank the left and right banks of the river near the eastern end of the lake. The top of the Bogus Rim lava is only about 25 m below the surface of this lake. Thus, the link between this lake and the landslides is dubious as there was nowhere for the landslides to slide.

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Plausible extents of landslide-dammed lakes in The Hole in the Ground

2009-09-29T16:26:00.001-07:00

I have developed polygons showing likely extents of lakes related to both lobes of the Doublespring Landslide Complex on the Owyhee River. Using a combination of LiDAR data, ArcGIS, and GlobalMapper in conjunction with the highest plausible geomorphic evidence of fluvial overtopping the following lakes result:

East Spring Landslide: 878 m lake elevation.

West Spring Landslide: 868 m lake elevation.

(it is possible that both are a few meters low...need some field data)

The correspondence / lack of correspondence of these lakes with various upstream landforms and deposits is surprising.

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Two New Gigapans, More on the Way

2009-08-19T21:55:00.001-07:00

Our Owyhee River field area is very amenable to the gigapan. On my last trip I took the time to acquire several new GP images. Some are huge and still churning. But for now, check these out:

http://gigapan.org/viewGigapan.php?id=30647

http://gigapan.org/viewGigapan.php?id=30814

See the full gallery on posterous

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Yes. There is a sediment lens trapped between two flows in the West Crater Lava

2009-08-12T22:14:00.001-07:00

It is at Dogleg Bar. You can see it as a squinty-eyes shaped discontinuity in the lava stack to the right/east of the terrace sequence. I got out there today to find out that the lens is comprised of weakly cross-stratified, moderately sorted, pea to pebble gravel composed entirely of cinders and fragmented vesicular basalt with a glassy outer rind. Fairly clear evidence for the river dealing directly with hot lava. I suspect that there are more examples of this. I tried to get to the big face in Qbw where the prominent fracture is located between Bogus Falls and Dogleg. Too steep and dangerous to peer over the edge far enough. The photo I have of that area from last May, however, is suggestive of a sediment lens akin to the one I visited today.

See the full gallery on posterous

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Dogleg Bar figure with hillshade and profile

2009-08-02T15:14:00.001-07:00

These were made in surfer and grapher. For further editing, the emf file can be modified in illustrator. Said file will be placed in shared folder.

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Distilling LiDAR data with ArcGIS

2009-08-02T13:53:00.001-07:00

Turns out that ArcMap has some very useful tools buried in the toolbox for evaluating the basic characteristics of LiDAR data. For example, using the 3D analyst extension, it is possible to collate the basic parameters of *.LAS tile sets. For example, the following steps:

3d analyst > conversion > from file > point file information

will generate a polygon shape file of the data tiles and will atrribute each tile set with measures of point count, point spacing, max z, min z, etc. This is useful because it is nice to have a simple polygon file that shows the extent of the data and some of the metrics in the attribute table are important to have for applying other types of processing to the data. In the figure above, the tiles are labeled according to object id (OID) rather than filename because the filenames are exceedingly cumbersome.

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Example of Map for GSA Figure

2009-08-01T18:38:00.001-07:00

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Profile smoothed with running average...does it matter?

2009-08-01T15:33:00.001-07:00

Basically, this smooths out the sagebrush and rabbitbrush.

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Generalized geology added at 80% transparency

2009-08-01T15:19:00.001-07:00

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By popular demand: Alternate Dogleg Bar profile

2009-08-01T15:18:00.001-07:00

I will load these data and smooth with a moving averge.

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Same Concept, 42% transparency

2009-08-01T15:01:00.001-07:00

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West Crater Dam Area, Owyhee River, OR

2009-08-01T14:56:00.001-07:00

This figure uses the hillshaded LiDAR and high-res Naip imagery at 60% transparency.

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Dogleg Bar, Profile Example 2

2009-07-22T22:31:00.001-07:00

Made with Global Mapper. Same conditions apply as previous. Note that I do know how to correct the no-data areas in the LiDAR with ArcGIS...learned at the Users Conference in San Diego last week. Just have not yet had a chance to apply the correction.

Once the missing data are smoothed/averaged, it will be easier to draw a profile. The final one should also be smoothed with a moving average function to eliminate the effect of bushes, etc.

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Dogleg Bar, Profile Example 1

2009-07-22T22:26:00.001-07:00

This was made with Global Mapper. Couldn't block out the no-data areas, but will use hillshade from prior post. It was made in Arc.

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Dogleg Figure example 1

2009-07-22T22:06:00.001-07:00

This is a straightfoward shaded relief image of the Dogleg Bar area using the 1-m LiDAR DEM.

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Draft cross section example using LiDAR

2009-07-07T13:25:00.001-07:00

From near Bogus point across the kipuka, etc. Shockingly simple to extract in GlobalMaper or ArcGIS. Smoothed in Grapher. Mocked-up in Illustrator. Will work on another that brings in other members of the family.

Fresh New Insights from the LiDAR

2009-06-26T06:17:00.000-07:00

Hey y'all. I spent three days at the AASG Annual meeting in Park City, UT this week. Gave a presentation in front of approx 30 versions of my boss about 'Simple Digital Geology for Typical Analog Geologists'...went very well and was a lot of fun. Had a chance to talk with Ian Madin of DOGAMI about LiDAR visualization. In 2 seconds he convinced me that using a combination of slope shading and elevation color ramping produces the best results in almost every setting. I do recall that, on our last trip, Natalia asked me why I didn't use this method on the maps I handed out. Good question. Now I do.

Here are some images of a familiar area:

The slope-shading method looks a bit less 'real' but provides an amazing enhancement of slope contrasts that reflect important contact relations. Try it out on the data yourself and you will be amazed at the new array of relations that will jump out at you. For example, look at the young landslide nested in a larger slide along the Saddle Butte lava flow in the lower left corner. Pretty obvious now, no? Probably blocked the channel. During field camp, I found one of these in the Artillery Rim complex that is nested in the older slide complex. It too flanks a notably narrow reach of the river and may be associated with a young blockage.

Yes. Some additional map details will be added soon.

Also, while at the meeting I spoke with Vicki McConnell (State Geologist of Oregon) about publishing the map. She is all for it as long as I (we) can help defray the cost of production. I suspect the NSF grant can help cover this. I will do the lion's share of the work, so shouldn't be too much.

West Crater-Dogleg area looking good.

2009-06-17T15:26:00.000-07:00

Mapping update. Things are cranking along. Still have some aberrant unattributed polys...

The Penultimate List of Map Units

2009-06-15T21:39:00.000-07:00

It is crunch time on the map. I have so many other maps to work on that I need to begin seriously riding the asymptote to the completion of this one. After many years of solo and collective field observations and various consultations, arguments, and friendly exchanges with most of the Yeehows, I have settled on this list. If you have grave concerns please, please, oh please let me know sooner rather than later. I will throw the correlation diagram up soon.

Hillslope Deposits

Qcf Undivided colluvium and alluvial fan deposits, Holocene to Pleistocene

Qc Colluvium, undivided, Holocene to Pleistocene

Eolian Deposits

Qe Eolian sediments, Holocene to late Pleistocene(?)

Deposits of the Owyhee River

Qra Active channel and floodplain alluvium, Recent to late Holocene

Qry Young fluvial sediments, Holocene

Qrty Young floodplain terraces, Holocene

Qrt1-n Fluvial terrace gravels, Pleistocene (numbered in local depositional order where appropriate)

Qrg Fluvial gravel, undivided, Pleistocene

Qgb Fluvial boulder bars, Pleistocene

Qgw Fluvial gravel of West Crater lava, late Pleistocene

Qrgo Older fluvial gravel, Pleistocene

Qgbr Fluvial gravels of Bogus Rim lava, early Pleistocene

QTgl Ancient, inter-lava flow fluvial gravel, early Pleistocene to Pliocene

QTga Fluvial gravel of Artillery rim, early Pleistocene to Pliocene(?)

Lacustrine deposits of the Owyhee River corridor

Qfl Fluvio-lacustrine sediments, undivided, late Pleistocene

Qflw Fluvio-lacustrine sediments of West Crater lava dam, late Pleistocene

Qfls Fluvio-lacustrine sediments of Saddle Butte lava dam, late Pleistocene

QTfa Fluvio-lacustrine sediments of Artillery Rim, early Pleistocene to Pliocene

Landslide Deposits

Qls Landslide deposits, undivided, Holocene to early(?) Pleistocene

Qlsy Young landslide deposits, Holocene to late Pleistocene

Qlsby Young landslide deposits composed dominantly of coarse basalt breccia, Holocene to late Pleistocene

Qlsi Intermediate age landslide deposits, late Pleistocene

Qlso Old landslide deposits, middle to early (?) Pleistocene

Alluvium of Owyhee River tributaries and local drainages

Qa Alluvium of tributary washes and alluvial fans, undivided, Holocene to Pleistocene

Qas Alluvium and related sediments of active springs, Holocene to late Pleistocene

Qad Alluvium of closed depressions and sags, Holocene to late Pleistocene

Qay Young alluvium of tributary washes and alluvial fans, Recent to Holocene

Qai Intermediate age alluvium of tributary washes and alluvial fans, late Pleistocene

Qao Old alluvium of tributary washes and alluvial fans, middle to early Pleistocene

QTa Ancient alluvium of tributary washes and alluvial fans, early Pleistocene to Pliocene

Basalt lavas of the Owyhee River corridor and surrounding areas

Qbcp Basalt of Coffee Pot Crater, Holocene*

Qbrb Basalt of Rocky Butte, Holocene (?) to late Pleistocene*

Qbw Basalt of West Crater, Pleistocene

Qbs Basalt of Saddle Butte

Qbsy Younger basalt of Saddle Butte

Qbso Older basalt of Saddle Butte

Qbc Basalt of Clarks Butte

Qbg Basalt of Greely bar, early Pleistocene

Qbr Basalt of Bogus Rim, early Pleistocene

QTbc Basalt of Bogus cliffs, early Pleistocene to Pliocene

QTb Basalt, undivided, early Pleistocene to Pliocene

Tb Undivided basalt lavas, Pliocene to Miocene (?)

Tbs Undivided basalt lavas and interbedded sediments, Miocene to Pliocene

*These lavas only on regional map, not in river corridor

Rhyolite lavas and sedimentary rocks

Tsv Interbedded volcanic, volcaniclastic, and other sedimentary rocks, Miocene

Tr Undifferentiated rhyolite lavas, Miocene

Yeehow Central

Owyhee Figs. 2 and 1...Last post of these, I promise.

And it continues...

Best guess Owyhee River path pre-West Crater lava (70 ka)

Owyhee Figure iteration 9076b-44m

Back to being my own graphics department

Psychedelic rendition of the NV-OR-ID borderland

Lava-paving and long profile development

New and improved with scale and slopeshaded base

The West Crater Lava Dam figure. Draft.

Owyhee Map Draft 994a-2c

Lava v. River, the case of the the Owyhee River

Second draft of Owyhee River and lava profile

Let the monkeys and pigs fly from where they may

Intracanyon lavas: 1m contours from LiDAR

Second draft, Owyhee Map

Draft Owyhee lava figure

Some Owyhee River landslide images with contours

Heavy Landscape Visualization: Owyhee River area

Owyhee River lava paleomag sites

Owyhee River Map going global

2010 UNR Geology Field Camp Maps

Field tour

Another year, another field camp.

Attabad spillway video

Owyhee Map at 1:50,000

Oh right...the Owyhee Map...almost forgot about it.

The Jackson Creek lava delta and the 'two' Bogus lavas

Lacustrine sediment between Bogus Rim lava and older Bogus lava

Upstream-most remnant of West Crater Lava on river-left

Three distinct basalt flows below Bogus Rim?

Young Basalts in Yeehow-ville: Even more ruminations from Duane!

Now with lava!

Very cool landslide visualizations: Owyhee River, Oregon

This one is making the rounds in the geoblogosphere...for good reason.

Vents-a-plenty

The latest iteration of the Owyhee Map...

Nearing the end...The Owyhee Map

Interesting Ramblings from Duane (with maps from Kyle)

NW of Saddle Mountain

Sacramento Butte

S of Hwy 95

SE of Rome

You want lava, landslides, inverted topography, lava-water interaction, and more?

Draft version: Major volcanic vents in the Owyhee field area (east sector)

Summer, 2009 Paleomagnetic Studies

Is there anybody out there?

Paleomagic Results

The 1160 m spillway of the Bogus Rim lava dam.

More on the recent landslide in Italy. (2 additional minutes)

Fa-freaking-nomenal

Cool Rio Grande Landslide Paper

Familiar Places?

Continuing concerns about the landslide dam at Attabad in Hunza, Pakistan

If you are one of the few that view my Geologic Frothings Blog. Please note that the newest manifestation resides at http://geofroth.org.

Owyhee River LiDAR drape on low-res Google Earth images

Killer Owyhee Pic of the Week #2

New and Improved Profile figure and other...

Lyell was a closeted catastrophist?

Sweet Owyhee Pic of the Week

Short clip of the Owyhee fly-over...

Slide Show from Today's Owyhee Fly-over

An amazing day in the field...

Will be visiting the field area tomorrow...in a plane!

Flash Earth and Geohacks...Who knew? Not me.

Croall et al. Poster from GSA

SR 410 Nile Valley Landslide (west of Naches)

SR 410 Nile Valley Landslide (west of Naches)

Impressive lava-river interaction in Argentina

GEOMORPHIC HISTORY OF RIVERS DRAINING THE EASTERN ANDEAN CORDILLERA (34–37°S) CONSTRAINED BY TEPHROCHRONOLOGY, U-SERIES DATING OF PEDOGENIC CARBONATE AND COSMOGENIC 3HE DATING OF BASALT FLOWS

Lava v. River example from British Columbia

Submerged tree in Clear Lake, Oregon

Intracanyon lava flows: Does the river give a dam?

Owyhee lava and river profiles: location

Owyhee lava and river profile figure...draft

Nice renditions of the Owyhee River area map

The lava flow-landslide link laid bare

Two pleasing renditions of the map

Bogus Rim Lava / Iron Point Dam...beginner's edition

Bogus Rim Lava / Iron Point Dam

GEOMORPHIC HISTORY OF RIVERS DRAINING THE EASTERN ANDEAN CORDILLERA (34–37°S) CONSTRAINED BY TEPHROCHRONOLOGY, U-SERIES DATING OF PEDOGENIC CARBONATE AND COSMOGENIC ³HE DATING OF BASALT FLOWS