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.