Wednesday, April 16, 2014

Digging Utah's Dinosaurs - Video: Digging It

Check out this video made by National Geographic in conjunction with their May 2014 issue.   They did a story about about the area that Snow College students also get a chance to work in:
Digging Utah's Dinosaurs - Video: Digging It

Monday, December 16, 2013

Fall 2013 Geology Field Studies - Westan Robertson (student)

During September of 2013, the Snow College Geology Field Studies class had the opportunity to go to Capitol Reef National Park.  Most of the area is part of a monocline (a one-sided fold).  Erosion of this fold exposes a many different rock layers from the Triassic Moenkopi Formation to the Cretaceous Mancos Shale.
                            from http://www.summitpost.org/capitol-reef-national-park/171316

We stayed at the UVU Field Station which is located in the park near Pleasant Creek. Exposed near the field station were the Moenkopi, Chinle and the cliff forming Wingate formation.

My favorite part of the field trip was the fault just north of Chimney Rock. We learned how to identify a fault in the field - the red Moenkopi was next to the green Chinle (instead of below it).  We also found evidence of the fault in the form of both slickensides and fault breccia.



This was my first experience with geology in the field and it helped me to ensure this was what I wanted to major in. It was great it help me to understand the concepts in real application. I look forward to the next trip.

Friday, April 19, 2013

Grosvenor Arch

Grosvenor Arch
Grosvenor Arch is located in the northwestern corner of Grand Staircase-Escalante National Monument in southern Utah. It is unique in that it is actually two sandstone arches towering 150 feet above the ground.1 The larger of the two arches is nearly 100 feet in diameter.2  The arch was named for Gilbert Hovey Grosvenor who was the president of the National Geographic Society and would become the first full-time editor of National Geographic Magazine.3

The arch is accessible from either the north or the south via Road 400, also known as Cottonwood Canyon Road. It is ten miles by car from the nearest paved road. When you reach the small parking area, there is a sidewalk that will take you almost right to the base of the arch.

Water (and to a much lesser extent, wind) persistently carved away at the landscape to form this structure. The arch is formed in yellow Henrieville Sandstone from the late stages of the Entrada Formation. The capstone layer is formed of darker Cedar Mountain from between the underlying Morrison and overlying Naturita Formations, and Dakota Formation sedimentary rock.4

1. http://www.utah.com/nationalparks/bryce_canyon/grosvenor.htm
2.  http://www.utah.com/nationalparks/bryce_canyon/grosvenor.htm
3. http://en.wikipedia.org/wiki/Gilbert_Hovey_Grosvenor
4.  http://www.digital-images.net/Gallery/Scenic/Southwest/Utah/GrandStrcase/GrsvnrArch/grsvnrarch.html

Dinosaur Wrangler


A white government issue truck speeds along the Cockscomb leaving a lingering trail of dust, the occupant seemingly uninterested in the stunning scenery that surrounds him. Another truck pulling a trailer creeps along, two sinewy cowboys dressed in Wranglers scan the landscape for stragglers, a Coors beer rests in the console, their cigarettes glowing a fiery red match the horizon as they are swallowed up in the dusk and another invisible valley. An unsuspecting car with California plates traveling towards Kanab crosses the plateau. The occupants probably unknowing that they have left Bryce Canyon National Park are unaware of the rich, biodiverse, paleo-treasure that lies to the east as they marvel at the rugged outcropping of rocks formed by the differential weathering of a monocline caused by a faulting in the basement rock during the Laramide Orogeny.

The wind carries the fine dust as it settles across the expansive dry landscape. The desert somehow becomes more dramatic with the knowledge that the region was once an area of moist peat swamps and rivers flowing into the Western Interior Seaway from the Sevier Highlands millions of years ago during the Cretacious Period. The Kaiparowits Plateau has not only seen a history of extreme climates but is also a plateau and a basin at the same time. The area to the east was uplifted during the Laramide while the Kaiparowits Basin was folded down. Later the area erosion of the Colorado River left behind a high plateau. This unique feature mixed with the rich paleoclimate created a perfect storm of sorts for dinosaur fossils and the occasional pristine preservation of a biological microcosm. Plants and animals frozen in place create a mysterious intrigue that pulls you back for more, a thirst to understand their origin, their life and their demise.

The amount of new species and understanding of the history of our earth that has come out of the Kaiparowits is just the tip of the iceberg. The Kaiparowits Plateau or Basin depending on your area of study, is on the forefront of humankinds understanding of paleontology of Late Cretaceous dinosaurs. A white government truck parks on the edge of one of the seemingly infinite outcrops of the Kaiparowits. A jackhammer, shovels, pickaxes, probes and paintbrushes wait for hands to uncover just a few more feet and maybe the skull of a new species.


-Albert Behling

CSI Cretaceous

While we were out digging up dinosaur bones Dr. Alan Titus told us that there is sometimes still evidence in the bones and around the bones of how the dinosaur had actually died.  I  (being a future forensic scientist) found this fascinating. I didn't realize that the same process that we use today to solve crime could solve the mysteries of the dinosaurs. It never occurred to me before that the way  dinosaurs died could be determined in the same way that we solve crimes and events of today!

Sometimes there are bones that have teeth marks in them which tells you that the dinosaur was attacked.   The pattern of teeth marks may help determine if this was the cause of death. The other fossils that are found around the bones and the type of rock that you find the bones in can tell you about the environment that the dinosaur lived in.

The Hadrosaur that we dug up was interbedded with clams, fossil wood, leaves and turtle shell.  The rock was also very clay rich. This told us that it was a probably a lake or pond on a floodplain. We also found a Tyrannosaurid tooth next to the bones.  Maybe our hadrosaur had been attacked by the tyrannosaurid.   More work needs to be done before we can determine this.


Thursday, April 18, 2013

Float Mapping

A few of us were able to go out looking for dinosaur bones close to the dig site. At first all we knew was to look close to outcroppings on the sides of the hills, but as we explored and searched the area we noticed patterns in the pieces of bone that we were finding. We would find pieces that looked extremely weathered in the small washes and
at the bases of hills. Once we found these pieces we would generally find more pieces higher up the hill above where we found the first. As we moved up the hillside the pieces we would find appeared less and less weathered until we wouldn't see any pieces at all. When we stopped finding bone we would brush away at the hillside where the last piece was found and sometimes find the source of where the bone fragments were coming from, usually from a bigger piece of bone still partly covered by earth. Float Mapping usually refers to finding loose rock below its source, but we were able to apply the same principal in finding where loose bone fragments came from. This same process is how many of the dinosaur bones are found in the Grand Staircase.

Hoodoos

HOODOOS

On our beautiful drive through the Grand Staircase National Monument to Camp K, we passed by some pretty cool structures, such as monoclines, hogbacks, arches, and my favorite, hoodoos!  Hoodoos are found all over High Plateau region of the Colorado Plateau.  They appear to have a "totem pole" type body shape, due to the erosion patterns of alternating hard and soft layers underneath a hard cap-like layer, acting as a roof.  For example, soft mudstone or poorly cemented sandstone covered by a protective layer of well-cemented sandstone, limestone, or basalt.  Further erosion of the softer layers causes the cap to be undercut, eventually falling off (balancing rocks), and the leftover cone is then quickly eroded (NPS.org).  This is a great example of differential erosion.  

Hoodoos are found mostly in hot, dry, desert areas.  On our field studies trip last spring to the Moab area, we saw tons of them, especially at the Fiery Furnace!  Interesting fact: minerals deposited within the rock give them the appearance of different colors throughout their height.  In this image, the iron oxide makes the rock reddish.

Information found from the National Park Service's Bryce Canyon website says that Hoodoos can be eroded when winter snow melt seeps into the cracks and freezes at night, called frost wedging.  When the water freezes, it expands almost 10 percent and pries open cracks in the rock, making them even wider; similar to how a pothole forms in a paved road.  Geologically speaking, they live a short life; their average rate of erosion is 2-4 feet every 100 years.

Information from National Park Service's webpage: http://www.nps.gov/brca/naturescience/hoodoos.htm
Pictured above:  Hoodoos found outside of the visitor center at Red Canyon on Rte 12 west of Bryce Canyon.   They are in the Claron Formation.