Structural Controls on the Location of Geothermal Cells in and adjacent to Dixie Valley, Nevada

Abstract

The Dixie Valley area in Nevada has been the focus of geological and geophysical studies for over 30 years. The issues addressed in many of the studies have been related to both tectonic movement and geothermal resources. While much attention has been given to post-late Miocene normal faulting and associated Basin and Range morphology, earlier extensional normal faulting is often given minimal consideration. In addition, it is not unusual for structural presentations of Dixie Valley to be truncated near the valley-range boundary. Modeling the bedrock structure underlying Dixie Valley, and modeling structural controls contributing to the location of geothermal cells without fully integrating the role of pre-NNE-striking normal faults that cross both the valley and the Stillwater Range markedly handicaps the product of the model. Earlier north-striking high angle faults could be playing a major role in developing localized near-vertical tensional dilations and pull-apart structures that host geothermal cells. The recognition of the role of dilation zones as a feature within complex extension structures should improve exploration models for geothermal resources in extensional terrains.