Nature of Transverse Fault Deformation in the Horse Range, Nevada

Event Center A & B

Most of the rocks in the Stone Cabin Fault Zone in the Horse Range, Nevada are folded, faulted, and tilted. Several cross-sections were constructed using Dr. Joan Fryxell’s unpublished map to show the present structural state of the area. One cross-section in particular shows that these rocks are tilted to the east. The other cross-sections show that the rocks are folded and overturned. The Sevier thrust belt runs through this area, and is a factor in what has happened in the Horse Range. Another factor is the extension that the Basin and Range province is known for, with significant crustal stretching that produced many normal faults. Evaluation of the geometry of the Stone Cabin Fault Zone is to determine its role relative to the Sevier orogeny and/or regional extension and/or some other regional relationship. Three possibilities for the setting of the Stone Cabin Fault Zone represented are a tear fault in the hanging wall of either an older thrust fault, or a younger normal fault, a strike-slip fault related to extension or normal faulting caused by north-south extension. The results from Fryxell’s map, and the six cross-sections suggest that this area has experienced normal faulting making horst and graben structures, creating north south extension. The maximum age of this fault zone is of Miocene, because Miocene rocks are the youngest ones cut by the faults.