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Abstract. Manual approaches for analyzing fault scarps in the field or with existing software can be tedious and time-consuming. Here, we introduce an open-source, semiautomated, Python-based graphical user interface (GUI) called the Monte Carlo Slip Statistics Toolkit (MCSST) for estimating dip slip on individual or bulk fault datasets that (1) makes the analysis of a large number of profiles much faster, (2) allows users with little or no coding skills to implement the necessary statistical techniques, (3) and provides geologists with a platform to incorporate their observations or expertise into the process. Using this toolkit, profiles are defined across fault scarps in high-resolution digital elevation models (DEMs), and then relevant fault scarp components are interactively identified (e.g., footwall, hanging wall, and scarp). Displacement statistics are calculated automatically using Monte Carlo simulation and can be conveniently visualized in geographic information systems (GISs) for spatial analysis. Fault slip rates can also be calculated when ages of footwall and hanging wall surfaces are known, allowing for temporal analysis. This method allows for the analysis of tens to hundreds of faults in rapid succession within GIS and a Python coding environment. Application of this method may contribute to a wide range of regional and local earthquake geology studies with adequate high-resolution DEM coverage, enabling both regional fault source characterization for seismic hazard and/or estimating geologic slip and strain rates, including creating long-term deformation maps. ArcGIS versions of these functions are available, as well as ones that utilize free, open-source Quantum GIS (QGIS) and Jupyter Notebook Python software.

The Ruby Mountain Detachment Fault (RMDF) is a regionally significant structure responsible for exhumation of the Ruby Mountains-East Humboldt Range (RM-EHR) metamorphic core complex (MCC). Despite numerous thermochronometric studies, many uncertainties remain concerning the rate, style and timing of the on-set of extension. The goal of this study is to use zircon (U-Th)/He thermochronometry to provide new constraints on the timing, rate, and style of exhumation of the Wood Hills and Pequop Mountains, which are part of the RM-EHR MCC. When did exhumation begin? Is the younging direction consistent with direction of tectonic transport? Can trends in effective radiation (eU) and age provide additional insight? Were the Pequop Mountains exhumed along the RMDF?