OF-98-08 Preliminary Quaternary Fault and Fold Map and Database of Colorado

This map shows information about faults and folds that are known or suspected to have been active during the Quaternary period. 331 pages. 11 plates. Digital PDF download. OF-98-08D

Note that this compilation has been superseded by the fully updated ON-006-15M Colorado Earthquake and Fault Map.

There are 92 faults and six folds described in this database. The majority of these are considered simple fault or fold structures, but a few are sectioned Quaternary faults where detailed investigations suggest that different parts ruptured independently in the past. There are also a few where they have been discounted as having been active in the Quaternary time period. The report is organized into 80 simple faults, four sectioned faults where each section is individually described, two suspect faults, 12 discounted faults, five simple folds, and one suspect fold. Included is a 1:500,000 statewide map plate as well as ten regional 1:250,000 map plates based on the USGS topographic products.