Fault-propagation fold in the Yeso Fm.
Image taken: 04/29/2004by: Peter Scholle
UTM Easting: 337148 m
UTM Northing: 3761770 m
(WGS 84 or NAD 83)
About this image
One set of faults are nearly parallel to the bedding planes; these are thrust faults indicating compressional stresses. The fold is termed a fault-propagation fold because it is the sliding of rocks along the thrust fault that caused associated strata to buckle and fold near the tip of the fault. The former presence of evaporite layers in these rocks (before they were dissolved) may have contributed to the abundance of small thrusts by providing planes of easy sliding.
This outcrop is at Stop 8 in our free: "A Geologic Guide to the Quebradas Back Country Byway" by Peter A. Scholle.
Image posted: 12-17-2021