Public Release: 

New Rocky Mountain field guide demonstrates the area's dynamic, enigmatic nature

Field guide includes information about Colorado's floods

Geological Society of America


IMAGE: Colorado's Front Range is showing glacial extent at the Last Glacial Maximum. view more

Credit: S.P. Anderson et al., GSA Field Guide 33, Chapter 1

Boulder, CO, USA - The U.S. Rocky Mountain region has been the subject of continuous, exhaustive scientific work since the first organized geologic trips to the area in the 1860s. Despite almost 150 years of scrutiny, the region's magnificent geology continues to challenge, perplex, and astound modern geoscientists. It is a testing ground for geologists and for big geologic ideas. This new book serves both as a progress report and a guide to future scientific questions about the region.

The volume's fourteen chapters, which span the region's 1.7-billion-year history, give a retrospective glimpse of early geologic ideas being forged, bring the latest mapping and analytical results from classic locations, and introduce techniques that will form the bedrock of our geologic understanding in the years to come.

Prepared for the 2013 GSA Annual Meeting & Exposition in Denver, Colorado, USA, the book features trips in Colorado, Utah, and Wyoming. But even as the book entered its final production stages, Colorado showed that it would not give up its mysteries easily. Between 9 and 13 September 2013, unprecedented heavy rains and catastrophic flooding hit the Colorado Front Range, taking lives and causing destruction from the foothills to the eastern plains. Nearly 15 inches of rain fell in Boulder, where the Geological Society of America is headquartered, with almost as much falling elsewhere along the Front Range.

Volume editors Lon D. Abbott of the University of Colorado, Boulder, and Gregory S. Hancock of the College of William and Mary were faced with a dilemma when final production of the book was underway. Two planned GSA field trips, including the Mahan et al. trip detailed in the field guide, had to be canceled because the field areas were inaccessible. The itineraries of other trips had to be altered. Because these floods have altered the landscape, some features and landmarks described herein may have been altered or may no longer exist.

Abbott, who co-authored the book Geology Underfoot along Colorado's Front Range, and Hancock were able to add a "note in proof" to provide readers with information about the floods. They write, "Although the Front Range frequently receives brief, intense rain events that trigger flash flooding in a single drainage, this event was unusual in that it spanned 2000 square miles and lasted for days. ... As we write this, flood damage reports are still preliminary, but even these incomplete assessments are impressive. Two hundred homes, 200 miles of state highway, and 50 highway bridges were destroyed."

A late-breaking field trip is now planned for Boulder, put together Abbott and colleagues to examine the effects of the 2013 Front Range flood on low-order streams and alluvial terraces in the area.


Individual copies of the volume may be purchased through The Geological Society of America's online store or by contacting GSA Sales and Service,

Book editors of earth science journals/publications may request a review copy by contacting April Leo,

Classic Concepts and New Directions: Exploring 125 Years of GSA Discoveries in the Rocky Mountain Region
Edited by Lon D. Abbott and Gregory S. Hancock
Geological Society of America Field Guide 33
FLD033, 388 p., $60.00; Member price $48.00
ISBN 978-0-8137-0033-5

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