Saturday, December 22, 2007

Holiday Greetings Yeehows!

Against my better judgment, I am lugging the family back to Oklahoma for the Holidays. The payoff? Some incredible geology shots from the airplane! This is the most relevant sampling for this research group. Consider them my presents to you. To reciprocate, please send relevant field observations and associated GPS coordinates from the Owyhee River!!

Killer view of lava cascades into Western Grand Canyon!

Large landslides along the Rio Grande, north of Albuquerque!

Wednesday, December 19, 2007

Lava Butte in Google Earth

Today, I noticed an announcement that Google Earth had again updated some imagery in Oregon. Now, the Bend and Lava Butte areas are looking good (see screen snag above). The rapids formed at each lava-river interface are easily detected.

Still no improvement in the Malheur County area coverage in Google Earth. Note that at AGU I had a chance to actually interact with some Google People, and made a point out of complaining (in a friendly way) about the SE Oregon problem. No promises, but some expressions of mild concern. I did score one of those cool Google light-up balls, however. No job offer.

Cosmic Mineral Separation Directive

As Stated by Cassie Fenton:

Mineral Separate Preparation for 3He Cosmogenic samples:

STEP 1: Remove only top 4 cm of the rock (for cosmogenic samples). (If you only use the top 3 cm or top 1 cm, etc., make a note of this. It affects correction of the 3He content in the rocks.) Break the top 4 cm of the rock sample into pieces small enough to fit the crusher (generally the size of a golfball, no bigger). I use a rock hammer and chisel for this process. In some cases, for harder samples, a rock saw is needed, but rarely.

STEP 2: Make sure you clean the crusher in between samples to avoid any contamination. This includes using a dry paintbrush, a vacuum, and/or compressed air to get any/all of the previous sample out of the crusher and out of containers used to catch/transport the sample.

Always save at least one golf-ball sized hand sample of your whole rock for an archive sample. You might need this for chemical analyses etc. in the future. Start with the crusher at its widest position and throw the rock pieces in, reducing the width of the crushing gap each time until you have a variety of grain sizes. You want the majority of your sample to fall in the [250-500 μm] and [500-1000 μm] mesh range (sieve sizes in the US are labeled differently – I used to use US sizes [20-60] or so), so you just have to eye it. Grains in the [125-250] range are okay for analyses too, but makes things a bit more complicated because the grains are much smaller (i.e. handpicking this grain size is slow and tedious). There will still be pieces larger than that, up to 1 cm or so, that’s okay. You want to keep some bigger pieces in case you need to crush more in order to obtain the amount of the mineral you’re looking for. Just don’t overcrush, or you’ll end up with a lot of powder (too small!!) and not mineral grains of desirable size.

STEP 3: Sieving. Here’s a short list of sieve sizes we use:

(From Comparison Table of U.S., Tyler, Canadian, British, French, and German Standard Sieve Series)

U.S. Standard U.S. Alternate Tyler mesh designation
2.00 mm 10 9
1.68 mm 12 10
841 micron 20 20
420 micron 40 35
250 micron 60 60

The sieves we use are the U.S. alternate 10, 20, 40, and 60.

Set the sieves up descending in mesh size from top to bottom. (i.e. the 10 should be on the top, followed by the 20, 40 and 60, with a screen-free container (fitting the stack) at the bottom) to catch the finest part of the sample. You can either dry-sieve or wet-sieve. Both have their benefits. With dry-sieving, you don’t have to wait for the samples to dry, before moving onto the next step. Wet-sieving tends to clean the samples up, so the smaller grain sizes (<>

Either way, place your crushed sample in the top sieve and shake until you have a decent separation (Usually takes ~5 minutes). Take each container and empty it into a properly labelled bag. The labels are as follows (sample # followed by sieve size range; ex: 040609-01 [10-20]):

Clean sieves between samples, using a toothbrush and a thin tool to remove grains lodged in the screen/mesh.

STEP 4: Cleaning: Rinse the sample in a beaker and slowly pour off the dirty water until it runs fairly clear (don’t lose any sample!). Allow to dry. Oven should not be above 55º C (to minimize loss of He from crystals).

STEP 5: Magnetic Separation: I start with a hand magnet and mesh sizes [20–40] and [40-60], unless there are olivines large enough to fall in the [10-20] range, then I use that fraction as well. Often, in my basalt samples, the matrix is very iron-rich and comes off easily with a fairly strong hand magnet. If the hand magnet provides a good separate, put the magnetic material back in the sample bag and save it. Save the non-magnetic part of the sample (olivine, pyroxene, probably some plag and calcite).


1) Hand magnet: Obtain a typical hand magnet (they’re fairly weak, but work well). Dump your minerals grains on a piece of 8X11.5 paper with a clean piece of paper adjacent to it. Place a plastic baggie or weighing paper over your magnet to keep magnetic grains from sticking to the magnet, thereby decreasing contamination between samples. Run the magnet over the mineral grains, placng the magnetic grains on the empty paper, leaving the nonmagnetic grains behind. In our case, we are generally interested in olivines, pyroxenes, and feldspar. These generally stay on the nonmagnetic side, unless they have lots of inclusions or are coated with magnetic material.

If for whatever reason, the hand magnet doesn’t yield a very good separation, move on to the Frantz magnetic separator.

You can also use a Frantz if the hand magnet doesn’t work. Make sure your sample is washed before using the Frantz.

2) Frantz Magnetic separator: It is best to work with a [40-60] range on this machine, but the [20-40] range is feasible. The larger grains just tend to clog up the sample cup every now and again.

Adjust the desired angle on the ramp by turning the proper knob/wheel. I usually use an angle between 15-20 degrees tilting away from me (15 degree works best). A shallow angle tilting down to the sample collection cups also seems most productive. It allows the grains to interact with the magnet for a longer period of time, allowing for a cleaner separate. Take your clean sample fraction and pour a small amount of it into the sample cup. Turn on all appropriate switches, adjusting the strength of the magnet by increasing or decreasing the amps. I usually start with 0.25 amps, run the sample through 2-3 times. This will separate out the very magnetic material from the less magnetic material. I then switch to a higher amp (somewhere between 1.0 and 1.5) and run the magnetic fraction (when run at 0.25) through (2-3 times). This will separate off the very nonmagnetic. Then I just play around with values in between until I get a nice separate of my mineral of interest. Before changing the amps, I check each collection cup under a microscope to see which has the largest amount of my mineral of interest. These values will vary with different samples. You just have to pick and choose, use what best suits your sample.

STEP 6: Heavy liquid separation: We use lithium metatungstate with a density of 3.0 g/cc. At this density, olivines and pyroxenes (“heavies”) sink and everything you don’t want (“lights”) floats to the surface.

Here’s the address for the company we order from. We use litium metatungstate (density = 3.0). It’s water soluble, allowing for a density variation and recycling.


15 E. Palatine Rd., Suite 109

Prospects Heights, Illinois 60070


We recently ordered 3 lbs at a cost of $144/lb, I think.

Here’s a list of equipment we use to

CRU-5000 Centrifuge

50 ml polypropylene, graduated, conical centrifuge tubes with caps

3-piece Whatman filter funnel (9 cm in diameter, 200 ml volume, 17.9 cm height, Whatman no. 1950-009)

Whatman filter papers (medium-fast (1), 9 cm in diameter)

- fill the bottom of centrifuge tubes with sample grains. (Don’t fill it past the 5 ml mark). Label clearly.

- add lithium metatungstate (at a density of at least 2.95, preferably 3.0 or greater) to the 25 or 30 ml line (depends on how much sample you use and how much heavy liquid you have to work with).

- Cap and shake all the tubes

- place in centrifuge at 1.5X1000 rpm for at least 10 minutes.

- have a doer of liquid nitrogen set aside and set up funnel/filtration apparatus.

- remove tubes from centrifuge,

STEP 7: Acids: I usually use HNO3, HCl , and HF to clean up the “heavies” samples. To get rid of any secondary calcite, start with dilute (5-10%) HNO3 and your “heavies” in a beaker placed in a sonicator for 15 to 20 minutes. Then use dilute (5-10%) HCl (in sonicator 15-20 minutes). Sometimes the minerals are well-oxidized. For example, oxidized olivines tend to have an iddingsite “rind” (a red coating) around them. Sometimes HCL will get rid of this. If it doesn’t, move onto a 5% HF solution.

HF treatment: WEAR HEAVY GLOVES, A LAB COAT, AND A FACE MASK. HF is very nasty stuff. Pour your minerals into a small glass or Nalgene beaker (HF etches glass, so if you use glass beakers, set them aside after that for HF use only) and add a 5% HF solution until it submerges your minerals. Don’t use too much. It isn’t necessary to fill the beaker, just top your minerals with the solution. Place in an ultrasound for 15-20 minutes, depending on how oxidized your sample is. Check your sample regularly to make sure you don’t dissolve you minerals completely. Pour off HF into waste container, rinse your sample, and dry. Repeat as necessary, until the majority of your sample is clean (iddingsite-free).

STEP 8: Microscope check. After isolating the olivine/pyroxene, and cleaning them up with acids etc, you should have a good separate. I always check under a microscope and handpick out what looks like crappy mineral grains (grains that are still dirty, or that are obviously not oliv/pyroxene). You want the purest separate of olivine or pyroxene possible.

Sunday, December 16, 2007

What the Big Boss said...

I caught up with Mike E. at AGU and asked about the grant supplement to get LiDAR. Here's what I learned:

1. The proposal should be ~5 pgs and has no formal deadline.
2. We should wait till we hear the outcome of Rose's seed proposal, since that should (hopefully) be just a few weeks away, according to Josh R.
3. We should not ask for more than $50k.
4. We need to explain in detail why we want/need the LiDAR, of course (see my posting below). I briefly described three reasons to Mike that we've batted around before: to get the 3-D shape of the valley right for hydrodynamic modeling; to get the distribution of boulder sizes remotely by subtracting bare earth from first returns -- he liked that one, Jim -- and to characterize the wavelengths of mass movements that are impinging on the channel, as this will affect the scale of potential blockages and therefore probably flood character as well. He judged these to be reasonable justifications at first pass, but we will have to substantiate the case in detail. In particular, I think we really need to demonstrate the nature and magnitude of the improvement we get in the hydrodynamic modeling if we use LiDAR rather than the 10 m DEMs. Can we feasibly try this with the Deschutes LiDAR (which Jim has) as a demonstration? Rose, what say ye? If the effects are not great relative to other sources of uncertainty in the modeling, then I think our case is weakened significantly.

5. We need to explain WHY FUNDING FOR LIDAR WAS NOT INCLUDED IN THE ORIGINAL REQUEST. I want your input on this last matter in particular. Some of the reasons for the original omission, though perhaps ultimately the most truthful, are not going to sound very persuasive in a proposal (e.g., we thought it would inflate the budget too much, or we didn't realize how much damn work all the manual surveying would be, etc.). So, let's hear some wordsmithing. Ready, set, go.

Tuesday, December 11, 2007

Possible LiDAR coverage request

I have taken a stab at plotting a LiDAR coverage pattern that could form the basis for grant supplement request. It's obviously tricky trying to keep the footprint shape both as simple and as small as possible while capturing the irregular pattern of the river corridor. I'm not sure we can even request a pattern as complicated as the one I've outlined here. These four polygons sum to ~208 km2 or ~51,500 acres (for some odd reason, NCALM seems to like using acres as its unit of area), which is within the range of the other NCALM requests I've seen (see, e.g., slide #26 in ). Assuming a cost of about $0.75/acre, which is unreliable but is the only price info I've been able to find (see slide #24 in the .pdf above), our request would be for about $37,000. If Rose's request for 40 km2 or ~10,000 acres is funded, we can reduce the grant supplement request by about $7500. I don't know if this sum is considered reasonable for a grant supplement, but I will approach Mike Ellis at AGU and ask him. Any comments on the size/shape of this pattern?

Monday, December 10, 2007

Correlation Madness.

Thus far, I have spent 10s of hours on the map. As a consequence, the correlation diagram has evolved significantly. The colors in the snippet do not match the map yet, and some of the unit labels have changed. Also, it is likely that some units will be added and some will be dropped as the project continues. All part of my mapping process, and is often maddening to my colleagues. Nonetheless, check it out and go with the flow.

Friday, December 7, 2007

Tofu much nicer (but still Tofu)

Made some decent strides on the map in THIG today. Check it out. Pretty much the most complex area I have mapped in a while. Thankfully, I don't have to parse out the bedrock.

The Hole in the Ground is Tofu

Have spent many hours mapping the Hole in the Ground area. It is total tofu. Here is the current rendition. In the process I have added some new units that make sense now that the map has progressed. So far, I have focused only on the north side of the river.

Thursday, November 29, 2007

Base of Bogus Lavas

Here are three images that show the base of the Bogus lava where it sits on tilted to soupy-looking yellow sediments. These images are from the cleft. That is the spot that led me to the inference that the Bogus lavas were deposited on landslid materials--note the tilted brown stuff evident in the panorama. Everywhere I have since seen the base of the Bogus (upstream) it rests on more obviously in situ volcanic rock or flat-lying soft rocks.

Supplemental grant proposal to get LiDAR

Gang -- I'm going to follow up w/Mike Ellis on what exactly he'd like to see in a supplemental grant proposal to get LiDAR for our study reach on the Owyhee. I'd like to be armed w/a clear sense of what we want LiDAR for and w/information about the size, shape, and therefore approximate cost of the data. We have discussed the former a bit -- e.g., when Kyle was visiting Portland a couple of weeks ago -- but I'd like to solicit broader input on this matter, as the justification will be crucial. I think we need to show that LiDAR will give us essential data that we can't reasonably get any other way. As for the size of the area we want flown, I'd like to hear what you folks think. I don't know what the limitations are in terms of shape (how complex can the corridor polygon be?), but we'll probably have to do some iterating on the polygon we're going to request. My intuition is that requests larger than about $60k might raise some alarm, so we need to be judicious. Does anyone else have a sense of what constitutes a reasonable request for a grant supplement? I also asked Josh Roering (who is on the NCALM committee) when Rose will hear about the student seed project she proposed. Please post your thoughts on LiDAR justification and desired coverage here.

Tuesday, November 27, 2007

New Mapping Tool--Enforced Involvement?

View Larger Map

Google maps just introduced a terrain mode which is a nice way to visualize the regional setting of a map. More importantly, they also just introduced:

1. Collaborative mapping
2. kml file importation capability.

Improvement 1 allows for multiple users to edit a common, online map. The one I have included shows some key photos along the river that are useful in developing the geologic map in the office. Now that a map can be collaboratively shared, any invited mapper can post photos that they think are particularly useful for visualizing geology. In the Owyhee example, I am interested in a set of photos spread out along the entire length of the study reach (and beyond, if appropriate). All it requires is a very short amount of time to become familiar with the interface and a set of photos available somewhere online. I use Picasa Online Albums, but any program should work.

Improvement 2 allows for direct integration of data generated using Google Earth into a collaborative map. It has been possible to export kmls for some time from Google Maps, but importing has been missing. This is a huge leap.

Eventually, I will be inviting all Yeehows to post some photos that they think will help me compile the map. Please try to participate.

The Geologic Map in Progress

Here is a snippet of the map in the surprisingly complicated Lambert Rocks reach of the Owyhee River. This still needs some work, but shows some good progress. The colors don't quite match the correlation diagram I posted a while back. Will fix this eventually. I have mapped a larger area, but am having some trouble outputting the .jpg of the whole map. Yes, the labeling is bad and the landslide symbol is scaling poorly. These things will be fixed.

Wednesday, November 21, 2007

Extremely Cool Map Site

Rest assured that I am very busy working on the Owyhee River map. I will post a snippet soon. Have solved the label point problem encountered in Portland (easy fix). In the meantime check out this really cool site of the map exhibit at the Field Museum in Chicago:

Tuesday, November 20, 2007

Mapping landslides in the study reach

Here's a question to follow up on some discussion we had during Kyle's recent visit to Portland. Jim suggested that it would be useful to map large, coherent chunks of failed material (when they are clearly distinguishable) within the landslide boundaries. These would be mapped as bits of the parent lithology (e.g., West Crater flow or whatnot). The advantage of this approach is that it retains some of the information about rocktypes involved in landsliding that is surrendered when landslides are simply mapped as "Qls." My question is, how can/should we distinguish on the map between failed material and bits of in situ material that poke out within a landslide complex?

Thursday, November 8, 2007

Updated Correlation Chart

This version includes the possibility of Plio-Pleistocene landslides. Thanks to Liz for pointing out the omission. Any other takers?

Geodatabase Point Data

Stations (site specific data)

[kind] O = generic observation

[kind] A = age

[kind] G = graphic data

[kind] R = sample sites

[kind] Y = analytical

Age categories (prefix 1)

a = Argon-Argon

r = radiocarbon

t = tephrochronologic

c = cosmogenic
Graphic data categories

p = photograph

s = sketch
Sample site categories

r = rock

s = sediment

t = tephra

Analytical categories

f = fluvial transport direction

g = fluvial gravel lag

This is the structure of point data that we have built into the geodatabase. It covers all of the ground that I could recall for this project. Please look it over and let me know if you see a problem or an omission. *Note that the category for 'generic observation' very often includes a photograph or a graphic (sketch). This may be parsed too finely. That being said, I just noticed that I need to include a code for osl sample (Ao).

Thursday, November 1, 2007

Rinehart Canyon Lava Outcrop

I am heading out to a different field area, so I thought I would leave you with an interesting shot while I take a week off from the Owyhee. This is a picture of the Bogus lava outcrop at Rinehart Canyon. Here, the Bogus Rim basalt overlies a considerably thicker pile of 'older Bogus lavas'. The tapered marginal pinch of the Bogus Rim unit is hilarious in its clarity. This contrasts with the weirdness associated with the seemingly detached block surrounded by sediments along the base of the lower lavas, which have an otherwise obvious lower contact. Of equal interest is the scale-providing 'surplus' farm equipment on the slope. Thanks to Cooper for the inset detail.

Map of OSL Sample Locations

Zoom in on this map for details. Be sure to use satellite mode.

View Larger Map

OSL Sample #4

This sample comes from the nicely exposed stack of lacustrine mud and fluvial sand on river left directly across from the site of sample #3. Nice cross-bedded sands with some flaser-like, short, silty sand ribbons. Cooper and I concluded that this was the most amenable horizon in the section, but also noted that with more digging we would probably find others.

Wednesday, October 31, 2007

OSL sample 3

This was a 'choice' sample location in terms of sediments and stratigraphic position. This is not too high above the river on river right, well below the top of the West Crater flow. It remains to be seen as to whether this is lacustrine sediment associated with the West Crater Dam. If so, these sediments provide a constraint on the paleo-profile at the time (and place it lower than I would have suspected). Upper photo shows where we sampled and also the location of the tephra bed higher in the section (the white line with some obvious digging disturbance). The lower photo shows the exact sample spot at the base of the exposure. Sample 10050704. This is the stratigraphically lowest sample. This sample is in the top tier of priority for analysis because it seems like an ideal case.

OSL Samples 1 and 2

I am finally getting around to submitting the OSL samples to the lab at Utah State. I am posting photos of the sample sites for everyone's information. The photo below is from the location at the upstream end of the West Crater Flow below Bogus Point on river right. Here we sampled some likely fluvio-lacustrine seds that are capped by eolian sediments. Two samples here that straddle a boundary formed by a silty bed. Samples from here are 10050703a and b. This package is the highest exposure relative to the river. These two are the lowest tier priority owing to the clay beds.

Tuesday, October 30, 2007

Take Aim at the First Stab at a Correlation Diagram

NBMG recently hired a new chief cartographer with an extensive background in ArcGIS. As a consequence, our new approach to geodatabases is very comprehensive. I am climbing a relatively steep learning curve as I figure it out. One interesting aspect is that the new structure can pull a correlation diagram designed in excel (of all things!) right into a map layout. Any changes to labels and colors on the map are automatically updated in the correlation diagram.

Thus, instead of just mapping nonstop since we left Bend, I have been tackling the basic logistical issues associated with organizing the map data (see previous posts on unit labels and line types). So, today I tackled the correlation diagram. Please look this over and provide any comments you may have. Typically this type of chart evolves as the mapping progresses, but the first stab has to be decent. If you want to edit the spreadsheet directly, let me know and I will forward it. Note that I have added a chronological component to the landslide units. Not sure how easy it will be to divide, but decided the option was important to have.

Correlation Diagram of Late Cenozoic Geologic Units along the Owyhee River, Oregon

First draft, P.K. House, NBMG

Monday, October 29, 2007

Geodatabase to the nth degree

OK, this is a long one, but I wanted everyone to see the set of line-codes that I am integrating into the geodatabase. The codes are based on terminology in the new digital geologic map standards published by the FGDC. The seemingly overly detailed list is based on degrees of certainty relative to two aspects of lines on a geologic map: 1. What sort of line it is and how certain you are about that; and 2. How well the line's location is known.

Each funny looking code is a combination of the following characters that account for a variety of lines and a variety of degrees of certainty about what and where they are:

Line Types [kind]
  • C Contact
  • X Fault
  • R Rock body (marker bed or key bed)
  • Z Scarp (as feature, not contact)
  • M Morphologic
  • B Boundary
Prefixes [category]
  • g generic
  • l landslide
  • i internal
  • f fluvial
  • v volcanic
  • s sedimentary
  • z scarp
  • d depression
  • m morphologic feature
Suffixes [location]
  • c certain
  • q questionable
  • a accurate
  • x approximate
  • c concealed
  • i inferred
Code followed by Name
  • uB Boundary—undifferentiated
  • mB Boundary—mapsheet
  • pB Boundary—property
  • sB Boundary—scratch
  • wB Boundary—water
  • eB Boundary—exclusion
  • gCca Contact—Identity and existence certain, location accurate
  • gCqa Contact—Identity or existence questionable, location accurate
  • gCcx Contact—Identity and existence certain, location approximate
  • gCqx Contact—Identity or existence questionable, location approximate
  • gCci Contact—Identity and existence certain, location inferred
  • gCqi Contact—Identity or existence questionable, location inferred
  • iCca Internal contact—Identity and existence certain, location accurate
  • iCqa Internal contact—Identity or existence questionable, location accurate
  • iCcx Internal contact—Identity and existence certain, location approximate
  • iCqx Internal contact—Identity or existence questionable, location approximate
  • sCca Incised-scarp sedimentary contact—Identity and existence certain, location accurate.
  • sCqa Incised-scarp sedimentary contact—Identity or existence questionable, location accurate.
  • sCcx Incised-scarp sedimentary contact—Identity and existence certain, location approximate.
  • sCqx Incised-scarp sedimentary contact—Identity or existence questionable, location approx.
  • ldCca Sag-pond or closed depression on landslide (mapped to scale)
  • viCca Contact separating individual lava flows within same map unit—Identity and existence certain, location accurate
  • viCcx Contact separating individual lava flows within same map unit—Identity and existence certain, location approximate
  • viCqx Contact separating individual lava flows within same map unit—Identity or existence questionable, location approximate
  • gXca Fault (generic; vertical, subvertical, or high-angle; or unknown or unspecified orientation or sense of slip)—Identity and existence certain, location accurate
  • gXqa Fault (generic; vertical, subvertical, or high-angle; or unknown or unspecified orientation or sense of slip)—Identity or existence questionable, location accurate
  • gXqx Fault (generic; vertical, subvertical, or high-angle; or unknown or unspecified orientation or sense of slip)—Identity or existence questionable, location approximate
  • gXcc Fault (generic; vertical, subvertical, or high-angle; or unknown or unspecified orientation or sense of slip)—Identity and existence certain, location concealed
  • kRca Key bed—Identity and existence certain, location accurate
  • kRcx Key bed—Identity and existence certain, location approximate
  • fZca Fluvial terrace scarp—Identity and existence certain, location accurate. Hachures point down scarp
  • fZqa Fluvial terrace scarp—Identity or existence questionable, location accurate. Hachures point down scarp
  • fZcx Fluvial terrace scarp—Identity and existence certain, location approximate. Hachures point downscarp
  • lZca Head or main scarp of landslide—Active, sharp, distinct, and accurately located. Hachures point down scarp
  • lZcx Head or main scarp of landslide—Inactive, subdued, indistinct, and (or) approximately located. Hachures point down scarp
  • liZca Internal or minor scarp in landslide—Active, sharp,distinct, and accurately located. Hachures point down scarp
  • liZcx Internal or minor scarp in landslide—Inactive, subdued, indistinct, and (or) approximately located. Hachures point down scarp
  • vMca Flow lobe or lava-flow front—Identity and existence certain, location accurate. Hachures on side of overlying younger flow
  • vMqa Flow lobe or lava-flow front—Identity or existence questionable, location accurate. Hachures on side of overlying younger flow
  • vMcx Flow lobe or lava-flow front—Identity and existence certain, location approximate. Hachures on side of overlying younger flow
  • vMqa Flow lobe or lava-flow front—Identity or existence questionable, location approximate. Hachures onside of overlying younger flow
  • vMm Crest line of pressure ridge or tumulus on lava flow

Friday, October 26, 2007

Digital fold axis data for Oregon?

For some time, I've been wanting to look at the relationship between landslide distribution and structural features of our study region. I'd been thinking I'd look at proximity of landslides to fold axes, because it was fixed in my mind that digital fold axis data exist for Oregon, whereas digital strike and dip data do not. However, when I sat down to start figuring out how to do this analysis, I could find no such data. I plumbed the metadata and coverages associated with the 1991 Walker and MacLeod 1:500,000 map, as well as the info about the latest DOGAMI digital geology compilation. Nothing. Did I just fabricate this idea that fold axis data exist?? Does anyone have or know of digital data for central/eastern Oregon that might give clues about stratigraphic attitudes (there's a bit of info about fault plane dips, but that's all I could find)?

Wednesday, October 24, 2007

Base map and NAIP data up and running!

Here is a snippet of a digital mapper's dream. The topo and the NAIP imagery match up just fine in ArcGIS. Thought you might want to see an example from a favorite area. I am working with our new chief cartographer to develop the geodatabase for the geologic map. All the units are in, but now we are tangling with the line types and rock body types (more on the latter, later). Look for an upcoming post that shows the preliminary line set, the associated terminology, and explanation.

Tuesday, October 23, 2007

Dissed by Google Earth

Despite my faithful, essentially blind, allegiance to all things Google, the folks over at GE uploaded new imagery for all of Oregon except...wait for it...OUR FIELD AREA. Yikes. Presumably this ironic prank will soon be resolved. The attached image pretty much sums it up. All new, high-resolution data except for Malheur County. Rest assured that my cynical side (its only a side?) fully expected this type of development. Imagine the outburst that bellowed through my house when I chanced upon this one.

Saturday, October 20, 2007

Gravel on Bogus Rim Flow

Here's a nice shot of Cooper standing on the ~5 meters of coarse fluvial gravel that sits on the Bogus Rim lava approximately 1000' feet above the Owyhee River. The gravel is composed entirely of basalt (~90%) and rhyolite (~10%) clasts. It is only well exposed at spotty locations along the rim. The Bogus Rim lava comprises only the few meters at the top of the exposed section. The remainder is the undivided Bogus lavas which filled deep paleotopography in this area.

Friday, October 19, 2007

Clarks Butte Lava Candidates in Dogleg Area

At the Bend get-together, Cooper and I noted that there may be some Clarks Butte lava (Qbc; was AM-PM) outcrops in the Bogus Point-Dogleg Bar area. One is the prominent tabular feature just off of Bogus Point. The other we noted that day was a degraded pressure ridge near Bogus Creek Ranch. After looking at the photos in detail, I have found a few other features that have morphologies inconsistent with the freshness of the Qbw. Some have planar morphology similar to the blob off of Bogus Point and appear to be girdled with Qbw. There are also some weird pothole like features on some of them. Not certain about the Qbc correlation, of course, but these are viable candidates and worth a look.

The image is a slightly stretched part of the county mosaic from the NAIP data.

Thursday, October 18, 2007

First Draft of Map Units

Label Description
Tbu Undifferentiated basalt flows, Pliocene to Miocene
Tsv Interbedded volcanic and volcaniclastic rocks, Miocene
Tru Undifferentiated rhyolite flows, Miocene
Tro Older rhyolite flows, Miocene
Try Younger rhyolite flows, Miocene
Tsu Undifferentiated sedimentary rocks, Miocene
Trg Fluvial gravel, Pliocene(?)
Tfl Fluvio-lacustrine deposits, Pliocene(?)
QTbu Undifferentiated basalts of Bogus Butte
QTbr Basalts of Bogus Rim, Pleistocene(?) to Pliocene
QTrg Fluvial gravels of Bogus Rim, Pleistocene to Pliocene
QTbb Basalt of Greeley Bar, Pleistocene to Pliocene
Qrgu Undifferentiated fluvial gravel, Pleistocene
QTbg Sub-volcanic fluvial gravel, Pleistocene(?) to Pliocene
Qbg Sub-volcanic fluvial gravel, Pleistocene
Qbu Undifferentiated basalt flows, Pleistocene
Qbc Basalt of Clarks Butte
Qbs Basalt of Saddle Butte
Qbso Older basalt of Saddle Butte
Qbsy Younger basalt of Saddle Butte
Qrgo Older fluvial gravel, Pleistocene
Qflo Older fluvio-lacustrine sediments, Pleistocene
Qbw Basalt of West Crater, Pleistocene
Qrgi Intermediate fluvial gravel, Pleistocene
Qfli Intermediate fluvio-lacustrine sediments, Pleistocene
Qgb Fluvial boulder-gravel, Pleistocene
Qrt Fluvial terrace gravels, Pleistocene
Qry Younger fluvial gravels, Holocene to Pleistocene
Qra Alluvium of the active fluvial system, Holocene
Qlsr Landslide deposits, dominantly rotational
Qlsc Bouldery landslide deposits, dominantly cantilever
Qlsf Landslide deposits, dominantly earthflow
Qls Landslide deposits, undifferentiated
QTf Ancient Alluvial fan deposits, Pleistocene(?) to Pliocene
Qfo Old Alluvial fan deposits, Pleistocene
Qfi Intermediate age alluvial fan deposits, Pleistocene
Qfy Young alluvial fan deposits, Holocene to late Pleistocene
Qc Colluvium, Undivided, Holocene to Pleistocene
Qe Eolian deposits, Holocene to late Pleistocene(?)
Qel Eolian deposits, loess, Pleistocene

Yep, its late, but I had to get this list to the chief cartographer by today in order to get a geodatabase set up as soon as possible. Take a look and provide any comments if any come to mind. The list is somewhat stream of consciousness and may be missing a critical unit or may not reflect your conceptions. Let's work toward a consensus if needed.

maps and Bogus photos

Kyle - very cool maps. I definitely need a sabbatical with you, or at the very least a few days. Will you be in Reno at all around Christmas time or is your Oklahoma visit an extended one?

About the two Bogus flows... I thought I remembered discussing that topic when we sat on the plateau below the nipple and gazed through binocs at the tractor tread. We definitely discussed the unit to the right (in our view - toward the bend in the river) because it looked lower at the time. Glad the topography agrees.

Your question about the grinning gorilla is a good one - when we were looking at the photos at your house last week I was wondering the same thing - I hadn't remembered that there was more than one hyaloclastite, although I do remember that we found various pillow/hyaloclastite outcrops on our way down the ridge. It's a bit puzzling if it's really a hyaloclastite on a lower Bogus flow unless there was water in the local drainage from that side (otherwise, I don't see how a canyon-filling flow could form a lake). Also, the exposure just upstream from the grinning gorilla (across the gully) seems to show only a single thick Bogus flow (see photo).

Finally, the two thin upper flows with hyaloclastite look quite similar and different (at least in the photo) from the lower flow. Guess my vote is Greeley though I'm certainly not wedded to it!

The Artillery / Saddle Butte landslide situation

Here is a simple map in response to Rose's request about study areas for LiDAR data acquisition. This part of the Lambert Rocks quad would be the minimum area. Ideally, we could get data for the entire river corridor through this quadrangle.

Techie note: the annotations are done very quickly in Photoshop with a mini digitizing tablet from Wacom. Try writing like that with your mouse (yep, that is pretty much my sloppy writing). I use this thing all the time for making maps as well as sketching or tracing diagrams from my field notes. Really handy.

Wednesday, October 17, 2007

The Tiny Map Walks Amok

Today, I created a working base map using BigTopoPro. Above is a tiny snapshot of it. This may not be the final map, but it is what I will start with. Of course, I have no business mapping all of the old lavas in the eastern part, so that will be rather general and borrowed from other sources to some extent. Some of you (Cooper) will be sad to see that the rather narrow area to the west of the river omits large parts of the Saddle Butte flow. Remember, my goal is to map the river corridor within a buffer that shows enough of the surrounding area to frame the map and set the context. I will compile the final lines at a scale no larger than approximately 1:6000. Thus the final map will look good at 1:12,000 or 1:24,000. It is likely that a more irregular map area, possibly with a non-standard north reference will ultimately serve us best. I also foresee a smaller-scale map (1:100,000?) being developed that shows the main lava flows and their respective sources.

Tuesday, October 16, 2007

The Hole in the Ground

Turns out that 'All Topo Maps' is pretty easy to use and can generate a nice shaded relief. On a recent map (NBMG Map 156; 30Mb) I experimented with a shaded relief base and it worked pretty well. As an aside, check that map out, but use the right-click, 'save target as' option and then open it up in Acrobat. This map was a real trial and has over 6300 polygons.

In the case of the Owyhee, I will try a similar base, but may tone it down from snippet above. To fully round out the cartographic product, the final colors of the map will be shown in the legend over a clip of shaded relief so that the tonality is not confusing. If you click on the image above (or any image on the blog for that matter) you will see a hi-res example.

Base map update and software of Interest....

The Owyhee River study area base map:

I am formally beginning the process of creating the map and have decided to develop the base map using All Topo Maps v7, a product of iGage software that provides a platform for developing clean and seamless maps using various USGS topographic map products at a range of scales. As soon as the map is generated, I will post a link to it (give me a week or two). The map will be in NAD83, UTM Zone 11 and will have an irregular shape to encompass the relevant map area...actually it will be an inverted 'L' shape given the planform of the river, and may involve two panels. The iGage software also interacts intelligently with GPS units, but doesn't do the handy active downloading of maps, landsat data, and DOQQs that the Topofusion software does.

Goodbye to endnote and procite?

You may also like to know about a very cool Firefox add-on for collecting and managing scientific citations and references of all sorts. This program can quickly and simply extract all relevant bibliographic information from online scientific literature databases (eg., GeoRef, Google Scholar) to store and to generate ref lists for publications. It takes about an hour to figure out. I have already used it in conjunction with UNR library resources to completely research a recent mapping proposal.

Here's a quote from the site (and a link):

'Zotero [zoh-TAIR-oh] is a free, easy-to-use Firefox extension to help you collect, manage, and cite your research sources. It lives right where you do your work — in the web browser itself'

Monday, October 15, 2007

The Grinning Gorilla

This image is from the west cliff of the 'cleft' exposure on the south side of Hole in the Ground, looking to the east side. I think it looks like a gorilla. An interesting question here...are two Bogus Lavas Present? Or are there a series of Greeley advances? There are three palagonite zones present, but the lava cap on the lowest has an erosional cleft that appears to be filled with gravel. There are no palagonites on the west cliff, so it may indicate a relatively long-lived emplacement history of Greeley lavas. Any thoughts?

Birch Creek lava surprises

Back on the May trip, Jim, Kathy, and I traveled to Birch Creek to check out the lava flow relations. Everyone heard about the 'nipple' and the 'tank tread' but most didn't see them. We got some nice pictures, and I have posted some of them here that point out a relation that I did not catch until today. It appears that there are two separate Bogus Lavas here, not simply an eroded single lava. Whoops.
The Nipple: This is an obvious protrusion of lava that appears to be an erosional remnant of the Bogus Rim lava. The surrounding lava flow surface is covered with a veneer of exotic fluvial gravel, but the top of the nipple has no gravel cover. It may actually be that a younger Bogus flow is inset against both sides of the nipple. This seems likely in hindsight, particularly based on relations at the tank tread.

The tank tread was our first glimpse of the interesting cooling pattern of lava lobes(?) in which the columnar structure wraps all the way around the flow and looks like a tank tread. There is a spectacular example of this at Birch Creek. What I didn't notice when there is that the flow exposed on the east side of the ridge is actually a lower (inset?) flow. This relation is very clear on the aerial photos and the topo map.

Slightly more detailed version that also suggests an equivocal QT age for all things Bogus.

Can you teach an old Luddite new tricks?

We'll see how the answer to that one turns out, but I'm game to try, even if it's only as a passive viewer. The blog looks great.--Lisa

Kyle is dragging me into the 21st century

Hi folks - this is a new experiment for me BUT I'm eager to learn. As the lava flow perspective on rivers advances, I'll try to post tidbits (as soon as I figure out how to put photos on I'll post some from the Lava Butte field trip!) Kathy

2007 Field Traverses

This map is a clipped screen shot from Topofusion, a really quick and handy program for placing your gps data onto several possible basemaps. Shown are all of the foot traverses that I made between May 1 and October 10, 2007. There is a striking lack of coverage in the Dogleg Bar area that is compensated somewhat by older (river-trip) recons that are not added to this map yet.

Saturday, October 13, 2007

Who are the Yeehows?

Thanks to Kathy and Cooper for many of these photos.

Owyhee Slideshow 1

This is the first of several slide shows. If you click on a photo of interest, it will take you to the online photo album. I will try to make these include logical/topical photo sets as I organize my photos (and many from Kathy and Cooper).

This is only a test, but it just may work.

This is an official attempt to determine if developing a blog about the Owyhee that can include pictures, maps, and commentary (including commentary from all Yeehows) is a better approach than e-mail and ~semi-annual face to face meetings. I will keep all relevant parties apprised as information is added to this site.

The photo below is actually a sunrise over Bogus Point. It looks like a sunset. Perhaps this portends a similar paradox of successfully coaxing some or all of the group to collaborate in this weakly high tech way. Time will tell. Stay tuned.