Data release for Geologic Map of the Poncha Pass Area,
Chaffee, Fremont, and Saguache Counties, Colorado
Description
This release presents the GIS data (in GDB, shapefile, and
e00 [coverage] formats) and metadata for a 1:24,000-scale geologic
map of the Poncha Pass area in central Colorado. A cartographic
version of the geologic map, including map unit descriptions,
interpretative text, and accessory figures and tables, is being
separately published as a U.S. Geological Survey Scientific
Investigations Map (SIM). The map area is irregular in shape,
covering all of one 7.5' quadrangle (Poncha Pass) and parts of
five others (Mount Ouray, Maysville, Salida West, Salida East, and
Wellsville). The map boundaries were drawn to cover all of the "Poncha
mountain block", coincident with the approximately 15-kilometer-long
northwestern end of the Sangre de Cristo Mountains. The map data
convey the areal distribution of: (1) Proterozoic basement rocks
forming the core of the Poncha mountain block, (2) overlying
Tertiary volcanic rocks, (3) Miocene and younger basin-fill
deposits, (4) Quaternary surficial glacial and alluvial deposits,
and (5) faults and folds affecting all of the above units.