Image: Normal fault & drag folds (eastern flanks of the Bighorn Mountains, Wyoming, USA)

Description: Normal fault & drag folds in Wyoming, USA. The Bighorn Mountains of Wyoming, USA are part of the Central Rockies Physiographic Province (a.k.a. Middle Rockies). Mountain ranges in the Central Rockies are cored by Precambrian-aged basement rocks (= igneous & metamorphic rocks) and have flanks of tilted Phanerozoic sedimentary rocks. The Central Rockies formed during the Laramide Orogeny (Late Cretaceous to Tertiary). The outcrop seen here consists of gently dipping, Paleozoic sedimentary rocks. The bend in the rock layers (best seen in the reddish unit) is due to faulting. Click on the photo to zoom in - a normal fault is present that cuts through the beds. The bent layers on either side of the fault are drag folds, formed by shear and solid-state deformation during faulting. Location: Rt. 14 roadcut at Sand Turn Overlook, eastern flanks of the southern Bighorn Mountains, western of Sheridan, western Sheridan County, northern Wyoming, USA (44° 48’ 18.37” North latitude, 107° 19’ 11.38” West longitude)
Title: Normal fault & drag folds (eastern flanks of the Bighorn Mountains, Wyoming, USA)
Credit: https://www.flickr.com/photos/47445767@N05/30253953413/
Author: James St. John
Usage Terms: Creative Commons Attribution 2.0
License: CC BY 2.0
License Link: https://creativecommons.org/licenses/by/2.0
Attribution Required?: Yes