Map showing upper Cenozoic rocks and deposits and Quaternary faults, Rio Grande rift, south-central Colorado

This map shows the faults and faulted rocks and deposits in the tectonically active part of the Rio Grande rift in Colorado, with particular emphasis on faults and deposits of Quaternary age. The Rio Grande rift in Colorado has been the subject of considerable recent geologic investigation. General compilations of the late Cenozoic tectonic features of the state of Colorado have been made by others. More detailed work used in compiling the map is shown in figure 1.