Great Sand Dunes aeolian system — Setting and history for discussion about the Crestone Crater

Abstract

The Crestone Crater is shallow depression with a diameter of roughly 100 meters, located in Great Sand Dunes National Park on the former Baca Ranch. It is 6.5 miles south of Crestone, Colorado and just west of the historic Liberty Road, (Figure 1). American settlement began in the 1860s, so people were in the area traveling the Liberty Road, but the crater was not noted until 1934. Local residents believed it to be the impact crater as there are reports of a fireball coming from the east in 1892 and again in the 1930s. Several studies have tried to determine the origin of the crater. To date, none has found evidence of an impact and they have speculated that the Crestone Crater is more likely an aeolian feature or a glacial feature or perhaps a seismic feature. Determining the origin of the Crestone Crater is not straight forward as it is located in a geologically dynamic area. It is embedded in aeolian sand that is underlain by water saturated, unconsolidated sediment and basin bounding faults. In the subsurface, sand ramps, piedmonts, and alluvial fans may be interbedded complicating geophysical interpretations. Lidar mapping and aerial imagery show other circular depressions near the Crestone Crater and though out the Great Sand Dunes aeolian system, so there are many possible explanations as to what type of feature the Crestone Crater is. Understanding all these factors it an important first step to studying the crater.