Thursday, September 10, 2009

Sample Prep at BYU Provo

Sample is obliterated into powder using a tungsten carbide crusher.
Powdered sample is pressed into pellets for trace element analysis using x-ray fluorescence (XRF).
Powdered sample is mixed with flux and other elements to be heated and fused into glass discs for major element analysis using x-ray fluorescence (XRF).

Monday, September 7, 2009

Chinle Formation

While I was in Arizona, I took my brother Jim out fossil collecting north of town.
The badlands north of Joseph City are part of the Chinle Formation (Triassic in age). The Chinle includes abundant deposits of petrified wood and some fossilized vertebrate remains -most of what I've seen are phytosaur.
It also includes Paleozoic chert clasts that contain fossils: bryozoans, brachiopods, and crinoids.
It's not uncommon to find evaporite mineral deposits in the region as well, but these are most likely quaternary deposits.

Saturday, July 11, 2009

Sample collecting: Henry's Mountains

I spent Monday night out in the BYU-Idaho Natural Science Center cabin in Island Park (North of Rexburg near West Yellowstone). Tuesday morning, I headed out with 3 other students to collect samples from flows of Basaltic Andesite from the Henry's Mountains which we'll use for a research project this fall. Brother Dan Moore led our group. We'll process the samples we collected at BYU in Provo this summer before school starts again in the fall.
Bro. Moore, our brilliant instructor:
Bro. Moore and Sam Grover
Fresh and weathered surfaces. Notice the pyroxene phenocrysts. They weather out into nice euhedral samples. Some of the soil on the ridge was full of them.
Our location (on a geologic map):
After we finished our collecting, we went up past Henry's Lake to the nearby Quake Lake in Montana and viewed the site of a significant landslide. Mass wasting to the extreme:

Monday, July 6, 2009

Craters of the Moon, National Monument

On the way back from my weekend in Boise, we stopped at Craters of the Moon, National Monument. Craters of the moon is an extensive series of basalt flows produced by a fissure eruption -part of the Snake River Plain volcanics. The flow is fairly recent, in a geological sense: 8 eruptive events over the past 15,000 years. The basalt flows of Craters of the Moon differ from other extrusive snake rvier plain volcanics in compositional and textural variety. It's an impressive sight -especially as you drive through and realize the extent of the flows (It's quite large).

Sunday, June 21, 2009

Menan Buttes

I helped lead a group of students on a field trip to the Menan Buttes last week. The weather was a lot nicer than the last tour I led and the group of students was awesome. They all seemed pretty fascinated and had a lot of good questions.
Xenoliths ("foreign rocks") within the basaltic tuff:
Topographic map of the Buttes. We climb the North Butte, the younger and larger of the two.
A profile of the Buttes from the BYU-Idaho campus

Thursday, June 4, 2009


The rock man has been on the road. And when I haven't been gone, I've been studying hard-core, or spending time socializing.
So if you have been disappointed in my lack of content, I'm sorry. One day I'll post something amazing, and it will have been worth the wait.

Monday, April 27, 2009


The BYU-Idaho Geology Department recently acquired a new digital camera and software for creating digital images of what you see through the lenses of a microscope. These are called "photomicrographs". These first few were slides of thin-sections of rock we use in our crystallography lab. I haven't got all the details worked out for mounting the camera and getting the optimal lighting conditions, but BYU-Idaho now has the capability to produce these things. And I'm the one who gets to figure out the details. It's exciting!

Tuesday, April 14, 2009

Garnet, Staurolite, and other Miscellaneous Schist

Yesterday, my friend and I went to Henry's Lake near Island Park, Idaho, just west of Yellowstone. The alluvial fans along the north shore's mountain front are rich with metamorphic mineral and rock samples.
This road-cut is a prime garnet-collecting site.
Here's a sample of the variety of metamorphosed pelitic rock present at this site.
Here's the road-cut that contains abundant staurolite (from the Greek "Stauros" meaning "cross") samples.
There was also a good amount of tremolite present at both sites.

Fossil Mountain

Fossil Mountain lies in the Southern end of the confusion range. In the photo above, the Eureka "quartzite" (in reality, a sandstone) tops the sequence, The Crystal Peak dolomite (the gray strata), the Watson Ranch "quartzite" (also a sandstone), then the Lehman Fm, Kanosh shale, Juab limestone, and Wah Wah limestone (I had fun saying that name).
Listric normal faulting has rotated strata, then a younger volcanic system emplaced the horizontal lava flows above (an angular unconformity).
Our instructor, Forest Gahn discusses stratigraphy and correlation of units across the valley. The Eureka unit near the top of the sequence lies at the valley floor and dips toward us: evidence of listric normal faults. Fossils found at this site: nautiloids, orthid brachiopods, gastropods, crinoids, ostrocodes, and sparse trilobites (typically fragmented); fauna of the Early Ordivician.
Surficial layers of sandstone units are bioturbated (burrowed), another indication of transgressive sea level.

U-Dig Trilobite Quarry

The U-Dig Trilobite Quarry is located in Western Utah, 34 miles north of Delta. The carbonaceous shale at the quarry is part of the Wheeler Formation.
I brought home abundant samples. Shown in the photo above are Asaphiscus and Elrathia. I also have some small samples of Perenopsis and the inarticualte brachipod, Acrotreta; all index fossils of the M. Cambrian.

More from the Historical Geology trip

Our first destination on the trip was the Museum of Ancient Life at Thanksgiving Point in Lehi Utah. I've driven past this place several times. From the outside, you'd think it was a hyped-up tourist attraction, with not a whole lot of scientific merit. Boy, was I wrong. Our host, and founder/designer/director of the museum, Cliff Miles has been pioneering recovery and restoration methods for fossil skeletal remains. We got to experience a tour of the behind-the-scenes restoration shop of the museum. In the above picture, Cliff shows us a restoration-in-progress of the neck of a barasaurus. Cliff's team pioneered the use of Bond-O in the restoration of fossils remains. (I found that fascinating. It's genius)
The above photo shows a sample being restored from out of the jacket it was transported in. Cliff explained that samples are more damaged the longer they remain in the sealed jackets. As the jacket plaster dries, it contracts and results in fracturing of whatever's inside. So his team works as fast as they can to get samples processed and out of their jackets.
A view of the Cambrian Fauna. I was impressed with the dioramas. How else could you get some visual sense of what ocean life looked like?
My reflection in a polished Banded-Iron Formation (BIF).
Archelon -massive sea turtle of the late Cretaceous.

Wednesday, March 25, 2009

Historical Geology Field Lab

For my historical geology lab, we took a field trip to Midwestern Utah. I have way too many photos and experiences to share, so I decided to divide the trip into different sites. I'll start with Notch Peak.
Seen in the photo above, Notch Peak is the highest peak in the photo. Notch Peak is formed by the Weeks formation, overlain by the Notch Peak formation, both Cambrian in age.
A Jurassic granitic intrusion caused contact metamorphism of the Weeks formation (basal layers of Notch Peak) and Lake Bonneville deposits make up the basin sediment.
The contact metamorphism was the highlight of this site. That's my instructor, Forest Gahn. (Can you spot the rock hammer on the outcrop?)
BYU Idaho students seated on the outcrop during the discussion, the altered Week's formation, capped by Jurassic "granite" (jointed diktytaxitic quartz monzonite), with Notch Peak dominating the skyline.The photo below shows a xenolith of the altered Week's formation included in the granitic rock. It also shows the detail of the altered Week's formation. Notice the interfingering of the lighter calcitic layers and the darker silicic layers and the garnets that have formed in the calcitic layers. This is an impressive outcrop -a great example of contact metamorphism.That's the start of my "digital unloading". I'll be posting more as I find time to do it. In the mean-time, I've got to pack for my trip to southern Utah and the Grand Canyon.