Preliminary Report on the Late Pleistocene and Holocene Diatoms of Swamp Lake, Yosemite National Park, California, USA

Swamp Lake, Yosemite National Park, holds one of California's longest sediment records, spanning approximately 16,000 years and providing high-resolution insights into past climate variability. Analysis of diatom assemblages from a 947-cm composite sediment core reveals that the lake has consistently been freshwater, oligotrophic, and circumneutral to alkaline throughout its history. Early sediments indicate sparse watershed vegetation, allowing organic-poor silt and clay deposition as the basin rapidly filled to at least 5 meters in depth. The record also captures significant Holocene lake-level fluctuations, with evidence of climatic events such as the Medieval Climate Anomaly and Little Ice Age preserved in the upper 50 cm. This study leverages varved sediments—a rare feature in California lakes—to reconstruct detailed paleoclimatic conditions, offering a critical window into the region's environmental past.

STARRATT, S. W., & ANDERSON, R. S. (2013). Preliminary Report on the Late Pleistocene and Holocene Diatoms of Swamp Lake, Yosemite National Park, California, USA. Phytotaxa, 127(1). https://doi.org/10.11646/phytotaxa.127.1.14