Two New Gigapans, More on the Way

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

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

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

See the full gallery on posterous

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

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

See the full gallery on posterous

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Dogleg Bar figure with hillshade and profile

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

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Distilling LiDAR data with ArcGIS

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

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

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

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Example of Map for GSA Figure

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

Basically, this smooths out the sagebrush and rabbitbrush.

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Generalized geology added at 80% transparency

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By popular demand: Alternate Dogleg Bar profile

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

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Same Concept, 42% transparency

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West Crater Dam Area, Owyhee River, OR

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

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Dogleg Bar, Profile Example 2

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

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

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Dogleg Bar, Profile Example 1

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

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Dogleg Figure example 1

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

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Fresh New Insights from the LiDAR

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

Here are some images of a familiar area:

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

Yes. Some additional map details will be added soon.

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

The Penultimate List of Map Units

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

Hillslope Deposits<o:p></o:p>

Qcf Undivided colluvium and alluvial fan deposits, Holocene to Pleistocene<o:p></o:p>

Qc Colluvium, undivided, Holocene to Pleistocene<o:p></o:p>

Eolian Deposits

Qe Eolian sediments, Holocene to late Pleistocene(?)<o:p></o:p>

<o:p></o:p>

Deposits of the Owyhee River<o:p></o:p>

Qra Active channel and floodplain alluvium, Recent to late Holocene<o:p></o:p>

Qry Young fluvial sediments, Holocene<o:p></o:p>

Qrty Young floodplain terraces, Holocene<o:p></o:p>

Qrt1-n Fluvial terrace gravels, Pleistocene (numbered in local depositional order where appropriate)<o:p></o:p>

Qrg Fluvial gravel, undivided, Pleistocene<o:p></o:p>

Qgb Fluvial boulder bars, Pleistocene<o:p></o:p>

Qgw Fluvial gravel of West Crater lava, late Pleistocene<o:p></o:p>

Qrgo Older fluvial gravel, Pleistocene<o:p></o:p>

Qgbr Fluvial gravels of Bogus Rim lava, early Pleistocene<o:p></o:p>

QTgl Ancient, inter-lava flow fluvial gravel, early Pleistocene to Pliocene<o:p></o:p>

QTga Fluvial gravel of Artillery rim, early Pleistocene to Pliocene(?)<o:p></o:p>

<o:p> </o:p>

Lacustrine deposits of the Owyhee River corridor<o:p></o:p>

Qfl Fluvio-lacustrine sediments, undivided, late Pleistocene<o:p></o:p>

Qflw Fluvio-lacustrine sediments of West Crater lava dam, late Pleistocene<o:p></o:p>

Qfls Fluvio-lacustrine sediments of Saddle Butte lava dam, late Pleistocene<o:p></o:p>

QTfa Fluvio-lacustrine sediments of Artillery Rim, early Pleistocene to Pliocene<o:p></o:p>

Landslide Deposits<o:p></o:p>

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

Qlsy Young landslide deposits, Holocene to late Pleistocene<o:p></o:p>

Qlsby Young landslide deposits composed dominantly of coarse basalt breccia, Holocene to late Pleistocene<o:p></o:p>

Qlsi Intermediate age landslide deposits, late Pleistocene<o:p></o:p>

Qlso Old landslide deposits, middle to early (?) Pleistocene<o:p></o:p>

Alluvium of Owyhee River tributaries and local drainages<o:p></o:p>

Qa Alluvium of tributary washes and alluvial fans, undivided, Holocene to Pleistocene<o:p></o:p>

Qas Alluvium and related sediments of active springs, Holocene to late Pleistocene<o:p></o:p>

Qad Alluvium of closed depressions and sags, Holocene to late Pleistocene<o:p></o:p>

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

Qai Intermediate age alluvium of tributary washes and alluvial fans, late Pleistocene<o:p></o:p>

Qao Old alluvium of tributary washes and alluvial fans, middle to early Pleistocene<o:p></o:p>

QTa Ancient alluvium of tributary washes and alluvial fans, early Pleistocene to Pliocene<o:p></o:p>

Basalt lavas of the Owyhee River corridor and surrounding areas<o:p></o:p>

Qbcp Basalt of Coffee Pot Crater, Holocene*<o:p></o:p>

Qbrb Basalt of Rocky Butte, Holocene (?) to late Pleistocene*<o:p></o:p>

Qbw Basalt of West Crater, Pleistocene<o:p></o:p>

Qbs Basalt of Saddle Butte<o:p></o:p>

Qbsy Younger basalt of Saddle Butte<o:p></o:p>

Qbso Older basalt of Saddle Butte<o:p></o:p>

Qbc Basalt of Clarks Butte<o:p></o:p>

Qbg Basalt of Greely bar, early Pleistocene<o:p></o:p>

Qbr Basalt of Bogus Rim, early Pleistocene<o:p></o:p>

QTbc Basalt of Bogus cliffs, early Pleistocene to Pliocene<o:p></o:p>

QTb Basalt, undivided, early Pleistocene to Pliocene<o:p></o:p>

Tb Undivided basalt lavas, Pliocene to Miocene (?)<o:p></o:p>

Tbs Undivided basalt lavas and interbedded sediments, Miocene to Pliocene<o:p></o:p>

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

Rhyolite lavas and sedimentary rocks<o:p></o:p>

Tsv Interbedded volcanic, volcaniclastic, and other sedimentary rocks, Miocene<o:p style="font-weight: bold;"></o:p>

Tr Undifferentiated rhyolite lavas, Miocene<o:p></o:p>

Sorry Yeehows, Our Secret is Out

The hydrograph above effectively encapsulates the ambient conditions of field camp. The overall wetness was pretty freaking shocking.

The field camp experiment is over. It was a muddy success. The region was (and still may be) under the influence of a persistent cutoff low pressure system that delivered record amounts of rainfall. It is true that the roads on the rim become somewhat challenging when they get wet, but we did manage to get seven vehicles all the way in and out to the Artillery Rim camp site (eventually). The first night at Rome launch, it rained nearly 1.5 inches. A record for Rome. It was truly disheartening. While lamenting my plight at the Rome Cafe very early on Saturday, the woman in charge at the time offered up access to the Grange building in Arock for us to use while we waited out the rain. Once in Arock, we were given access to the Arock School by an extremely gracious host. The school was a perfect fit for us...hot water, bathrooms, class rooms with high-speed internet, a playground, etc.

While at the school waiting out the rain, I gave a marathon lecture (with playground breaks) about the study area, the Quaternary, surficial geologic mapping, and of course provided various demonstrations about geotagging photos, how the gigapan robot works, how I make a map in ArcGIS, and how the magic pen works.

Thankfully, Duane and Caitlin were also there. Duane gave a lecture about the history of paleomagnetism and described how it works in the case of correlating basalt units in the field area.

Caitlin gave a lecture about her project. That night it rained like hell and we enjoyed watching a major thunderstorm plow through Arock. All the more enjoyable because we had a dry place to sleep.

The next day, we had a foreshortened tour of the field area (mud concerns) and made it to the Coffee Pot lava field and the vent by way of the Rockhouse Coffee Shop...all great places to take students.

The road to Birch Creek was in good shape so we peered over the rim. The students were moderately amazed because all they had seen of the river so far was the boring reach at Rome. We then headed out through JV and actually made it to Artillery Rim with only minor mud delays.

Once at the camp site, we approached the rim on foot as a group, and it was the perfect field camp moment. Everyone was awestruck by the view from there.

What then ensued were two perfect field days in the Artillery Rim landslide complex...full of ticks and snakes (lots of snakes), but the weather was perfect. The students had never faced such a complex array of landforms and deposits. Rest assured they have newfound respect for rivers, canyons, and Quaternary geology (and rattlesnakes).

The field camp mascot...saw 9 or 10 rattlesnakes in two days.

Here's an idea. Bring the girls from the Mackay School of Mines Mining Team into the field to dig for you. Next year, the augering competition. In less than 15 minutes they created the best exposure of the Qfl that any of us has ever seen.

The last day ended with an all night soaking rain, and we (the TAs, the cook, and I) were concerned that we may be stuck for a day. It was extremely wet that morning. But, alas, Duane (who proved various times on the trip that his last name is no fluke) and his field assistant Nicole showed up at our camp around 8 AM proving that the roads were viable. As we then rapidly started to take the camp down, it started to rain very hard and things were horribly wet. As we pulled out of the camp, there was a lot of water running down the rocky road past the gate. The rim roads were muddy as hell in the immediate area and one van got mired. It was a relatively easy extraction and we were again on our way through the mud. As we approached the (once-named) veneers of dreaded rim gravel, we changed the name to the sanctified rim gravel. The roads were fine and we proceeded out of the field with no incident.

Looks like my UNR field camp session will hit the Owyhee every year. It remains an amazing place worthy of sharing.

A beautiful evening looking north over the Artillery Rim landslide complex. Worth the trip.