Recent Glacial History of an Alpine Area in the Colorado Front Range, U.S.A.: II. Dating the Glacial Deposits

Abstract Recent glacial deposits in the Indian Peaks area of the Colorado Front Range have been dated lichenometricaily, using a growth curve developed locally for Rhizocarpon geographicum . Radiocarbon dates, where available, tend to support the lichen chronology. Three distinct intervals of glacia...

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Bibliographic Details
Published in:Journal of Glaciology
Main Author: Benedict, James B.
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1968
Subjects:
Online Access:http://dx.doi.org/10.1017/s0022143000020414
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000020414
Description
Summary:Abstract Recent glacial deposits in the Indian Peaks area of the Colorado Front Range have been dated lichenometricaily, using a growth curve developed locally for Rhizocarpon geographicum . Radiocarbon dates, where available, tend to support the lichen chronology. Three distinct intervals of glaciation, each consisting of several minor pulsations, have occurred in the area during the past 4500 years. The earliest advance (Temple Lake Stade) is dated at 2500–700 b.c. A later advance (Arikaree Stade) began in about a.d. 100 and ended in a.d. 1000. The most recent advance (Gannett Peak Stade) is dated at a.d. 1650–1850. It remains to be seen whether the Arikaree Stade was purely a local development or whether glaciers were advancing elsewhere in the cordilleran region during this interval. Alluviation on the plains east of the Colorado Front Range seems to have occurred during the waning stages of mountain glaciation.