Calibration, Review, and Geomorphic Implications of Postglacial Radiocarbon Ages in Southeastern Alberta, Canada

Abstract

AbstractCalibration of radiocarbon dates of postglacial geomorphic events in southeastern Alberta, Canada, reveals a strong association between type of geomorphic event and seasonality of insolation. The late glacial and postglacial periods can be divided into four major episodes: glaciation, ca. >20,000 cal yr B.P.; deglaciation, ca. 20,000–12,000 cal yr B.P.; landscape stability, ca. 12,000–10,000 cal yr B.P.; and landscape instability, ca. 10,000–0 cal yr B.P. This indicates that there was significantly more time than previously thought (12,000–13,000 yr) for postglacial processes. Glaciation, deglaciation, maximum landscape stability (indicating maximum aridity), and landscape instability did not lag behind minimum, increasing, maximum, and decreasing seasonality of insolation, respectively.