Field trip no. 1 from “Geologic Excursions to the Rocky Mountains and Beyond” field trip guidebook of the 1996 Annual Meeting of the Geological Society of America. Field Guide for the Detachment Structures of the Eastern Absaroka Range, Wyoming. (SP-44 has the complete set.) 37 pages. Digital PDF download. OF-96-04-01D
From the Introduction:
For more than a century, the Absaroka Range has been an important natural laboratory that has contributed to the education of thousands of students representing most of the colleges and universities of the nation. The purpose of this four-day field trip is to provide a forum in which the various detached extensional structures and large-scale mass movement deposits of the eastern Absaroka Range can be viewed, interpreted, compared, and contrasted. The foremost questions to be addressed will likely include: What factors (e.g., paleotopographic slope; direction and magnitude of bedding dip; seismicity; eruptive processes, presence and pressure of fluids) triggered the formation of these features? What factors facilitated movement across the gently dipping detachment surfaces? Were the detached rocks emplaced gradually or catastrophically? What data can be used to constrain the rates of emplacement? Were rates of emplacement similar throughout the Absaroka Mountains?
This field guide begins with an overview of the regional setting of Absaroka volcanism and associated detached extensional structures. Detailed site descriptions of the various detachments and their associated structures are integrated into the road logs.