Pierce College Geological Field Excursion 2010 Canyon Country, Utah Instructor: Tom Bush Geol 115

1. a photo essay by Brian Shoaf June 11-20, 2010

3. 2010 Canyon Country Field Excursion Geology Team (c ourtesy: Tom Bush, 2010 ) 3

5. La Sal Mtns. Beyond Buck Canyon (Personal Photo)

7. Lichen on Sandstone (Personal Photo)

8. Cryptobiotic Soil Crust (Personal Photo)

9. 300 Ma 290 Ma 240 Ma 205 Ma 138 Ma 66 Ma 1.6 Ma Present Day Massive wind-blown sand dunes Braided streams Massive wind-blown sand dunes Tropical streams , lakes and swamps Tropical tidal flats Cutler Fm. Includes: White Rim Ss (Wind blown beach sands), Organ Rock (Marine lowlands), Cedar Mesa Ss (Near shore sand dunes interfering with periodic floods) and the Lower Cutler Fm (Shallow seas) Evaporites from reoccurring seas flows in region Quaternary “ Work in progress” Deposits Tertiary La Sal Mtns. Abajo Mtns. Cretaceous Mancos Shale Dakota Sandstone Jurassic Morrison Fm Entrada Sandstone Carmel Fm. Navajo Sandstone Kayenta Fm. Wingate Sandstone Triassic Chinle Fm Moenkopi Fm Permian Cutler Fm./Group Pennsylvanian Honaker Trail Fm Caprock Member (Paradox Fm)

10. Navajo Kayenta Wingate Chinle Moenkopi White Rim Ss Kayenta Fm Wingate Ss Chinle Fm Moenkopi Fm Cutler Fm The first photo (personal photo) shows the rock formations present on Moab Canyon . The second photo (personal photo) also shows the different rock formations visible from Dead Horse Point on the Gooseneck in the Colorado River. The Rocks labeled were the most common formations we observed and discussed about on the trip. These formations are in the positions they’re in today due to erosional , depositional and techtonic processes. Top: Moab Canyon (Personal Photo) Bottom: Gooseneck (Personal Photo)

14. The Geologic timeline of Canyon Country dates back to Precambrian times. 4,600 million years ago, the Crystalline basement of North America formed because of a collision between two ancient continents. This collision formed the bases of mountains and other geologically significant formations. Later on in this time period, Depositions produced the Grand Canyon Supergroup which led to The Great Unconformity, a process caused by uplifts, faultings and other erosional processes. From the Cambrian Period through the early part of the Pennsylvanian period, the Colorado Plateau saw continued processes of marine deposition in the area because of seas that would come and go throughout time. These marine depositions helped the erosional process of the Plateau. Meantime, the Paradox Basin produced different layers of salt in and around what is now Arches. Towards the end of the Pennsylvanian period, Pangaea, the supercontinent broke apart. The North American tectonic boundary is created. The Triassic period brought with it the development of nonmarine conditions . Through part of the Jurassic, different kinds of sands, conglomerates, and other sediments flow into the area forming Moenkopi, Chinle, Wingate and Kayenta formations. The Tertiary period brought with it the Laramide Orogeny which caused wide-spread faulting and uplifts of the region. River systems also began carving canyons into the Plateau, which is still happening to this day. So far in the Quaternary period, the Plateau continues to lift while the rivers continue carving the rock.

15. Roadside Ruin (Personal Photo)

18. Chronic, Halka, 1988, Pages of Stone: Grand Canyon and the Plateau Country , the Mountaineers, Seattle Compton, R.R., 1985, Geology in the Field , John Wiley & Sons, New York Shue, Jerry, Neal Herbert, and Barbara Webb. Canyonlands Geology: A Visual Toolkit , Moab, UT : Canyonlands Natural History Association, 2010. Print. Canyonlands Cultural History , Canyonlands Natural History Association, 09/2007. Print. Land Use History of the Colorado Plateau . Northern Arizona University, Web. 7 July 2010. <http://cpluhna.nau.edu/>. &quot;Arches National Park, Utah.&quot; Geology of National Parks . Web. 09 July 2010. <http://3dparks.wr.usgs.gov/coloradoplateau/>. U.S. Geological Survey. Web . 09 July 2010. <http://www.usgs.gov/> .