15 k.y. paleoclimatic and glacial record from northern New Mexico

Abstract

The southern Sangre de Cristo Mountains, New Mexico, contain evidence of glacial activity from the late Pleistocene to late Holocene. Sediment cores recovered from an alpine bog (3100 m) trapped behind a Pinedale age moraine, ∼2 km downvalley from a high-elevation cirque, reached glacial-age debris and recovered ∼6 m of lake clays overlain by gyttja. Accelerator mass spectrometry dating, sedimentology, variations in magnetic properties, and organic carbon data reveal six distinct periods of glacial and/or periglacial activity. These include a late Pleistocene Pinedale glacial termination just before 12120 1 4 C yr B.P., a Younger Dryas chron cirque glaciation, an early Neoglacial periglacial event (ca. 4900 1 4 C yr B.P.), a late Holocene cirque glaciation (3700 1 4 C yr B.P.), as well as late Holocene periglacial events at 2800 1 4 C yr B.P. and the Little Ice Age (ca. 120 1 4 C yr B.P.). Cold events in the middle to late Holocene correlate with subtle ice-rafting events in the North Atlantic and records of cold events in North America and Europe and were probably hemispheric in extent.