Saturday, December 22, 2007
Wednesday, December 19, 2007
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.
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|
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
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
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
Monday, December 10, 2007
Friday, December 7, 2007
Thursday, November 29, 2007
Tuesday, November 27, 2007
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.
Wednesday, November 21, 2007
Tuesday, November 20, 2007
Thursday, November 8, 2007
|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|
|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
Wednesday, October 31, 2007
Tuesday, October 30, 2007
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.
Monday, October 29, 2007
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
- g generic
- l landslide
- i internal
- f fluvial
- v volcanic
- s sedimentary
- z scarp
- d depression
- m morphologic feature
- c certain
- q questionable
- a accurate
- x approximate
- c concealed
- i inferred
- 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
Wednesday, October 24, 2007
Tuesday, October 23, 2007
Saturday, October 20, 2007
Friday, October 19, 2007
The image is a slightly stretched part of the county mosaic from the NAIP data.
Thursday, October 18, 2007
|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.
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!
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
Tuesday, October 16, 2007
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.
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 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.
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
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.