COLORADO’S STRATIGRAPHY RE-CHARTED, DIGITAL ACCESS TO STATE’S STRATA AND EVOLVING LANDSCAPES

Colorado’s stratigraphic chart has been digitized and updated to reveal state-wide patterns of orogeny, sedimentation, and erosion. To illustrate these patterns, we followed Richard Pearl in dividing Colorado into eleven basin areas that each have distinctive stratal successions. The digital stratigraphic chart is tied to paleogeographic maps published by Ron Blakey, to paleogeologic maps developed from the literature, to ancient landscape paintings produced by the Denver Museum of Nature & Science (DMNS), and to outcrop photographs.

The process was based on simplicity, using over the counter web tools, Adobe Illustrator, and Photoshop. The introductory page provides an index map of Colorado defining the basin areas that form the columns of the chart. This map also serves as an index for subsurface cross sections colorized from a 1977 Rocky Mountain Association of Geologists (RMAG) Research Committee compilation of electric log sections. Measured surface sections published by the RMAG are also linked. Plans include additional layers of information that may include paleontological resources, radiometric dates, and detrital zircon age spectra. An expanded version of the younger portion of the chart serves to amplify the better known and dated rocks of the past 80 million years.

Our goal is to provide a tool for students, geologists, and stratigraphers of any level to synthesize Colorado’s stratigraphic patterns. Ongoing research at the DMNS and other institutions will continue to inform this living document for all to share.

This work is anchored in the knowledge and data of our colleagues. We thank them and the organizations that have shared their data and feedback with us. Because this chart is essentially a hypothesis, further comments and suggestions are welcomed.