Subject: Paleozoic Impact Crater Strewn Field, Douglas, WY
Date: Sunday, September 15, 2019
Time: 06:00 – 18:00
Leaders: Kent Sundell + 1-2 students (TBA)
7am - Leave Cheyenne.
8:45 – Orin Junction Rest Area.
9:30 – Douglas Impact Site (20 miles south of Douglas, Wy).
9:30 – 2:30 Hike up east flank of Sheep Mountain Anticline to directly observe 6-8 meteorite impact sites in the uppermost Casper Formation.
11-12 Noon Eat Lunch while hiking through the crater field on Sheep Mountain.
3:00 Return to Orin Junction.
5:00pm Return to Cheyenne.
Fees: $250.00 for Professionals / $75.00 for Students
Limit: 32 participants
Description: On this unique field trip the participant will see more impact craters in one day than anywhere else on Earth. Only by visiting the Moon or another planetary body could you see more. The Douglas Impact Site was named and formally described in the following Free Online Scientific Report published by Nature last year: This trip requires strenuous hiking up steep rocky slopes. Please bring and use walking sticks, sturdy hiking boots, sun screen, a hat, 2-3 quarts of fluid, and sun glasses. Rock hammers are optional. Rattlesnakes, scorpions, cactus, poison oak, and barbed wire fences are a few of the hazards we may encounter (still easier than going to the Moon and a whole lot cheaper).
The Douglas Impact occurred at the Pennsylvanian/Permian boundary at the contact between the Casper Formation and the overlying Goose Egg Formation redbeds about 280 Ma. This is the same contact as the Minnelusa/Opeche contact in the northern Powder River Basin. More than 130 possible craters have already been observed by Google Earth, drone flights, and field observations. About 15 impacts have been confirmed by thin section analysis to contain shocked quartz, verifying their origin. Some of the 130 possible craters will probably not be confirmed, but many more are expected to be found. Come see the crater rims, vertical and overturned margins, ring fractures, impact breccias, shock metamorphosed quartzite, radial fractures with impact breccia filled veins. An astrogeologist’s dream come true. Stand where Harrison (Jack) Schmidt (the last man and only geologist to walk on the Moon) has stood before. Discuss and argue the many hypotheses pertaining to this recently recognized ancient impact surface on Earth. Discuss ongoing research by Casper College faculty and students using drones, field mapping, geophysics, geochemistry, and hopefully future drilling to elucidate this newly recognized natural wonder of the world.
Contact: Dr. Kent Sundell
307-268-2498 (office) 307-259-5258 (cell)
For more information please see:
Kenkmann, T., Sundell, K., and Cook, D., 2018, Evidence for a large Paleozoic Impact Crater Strewn Field in the Rocky Mountains, Nature Scientific Reports, V 8, Article no: 13246. https://www.nature.com/articles/s41598-018-31655-4