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.

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.

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:

http://www.fieldmuseum.org/maps/

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?

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).

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.


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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.

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.

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

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

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)?

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.

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.

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.

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.