Mapping the Younger Dryas Landscape of the San Dieguito Paleochannel

Summary

This is an abstract from the "SAA 2024: Individual Abstracts" session, at the 89th annual meeting of the Society for American Archaeology.

Humans had established presence on California’s Channel Islands by the Younger Dryas (YD) Period (~12.9-11.7 ky BP), during which stable sea level was relatively stable for ~1 ky. No archaeological sites from this time have been identified on the nearby continental shelf, likely destroyed by subsequent rapid sea level rise, but submerged paleochannels exhibiting landscape and sediment preservation could harbor archaeological materials. We mapped the paleochannel offshore the San Dieguito Lagoon in Del Mar, California to reconstruct the YD landscape. We imaged the subsurface by sub-bottom profiling and identified the YD paleoshoreline between 57-60 m depth, ~3 km from the current coastline, to delineate the subaerial portion of the landscape and constrain local sea level. Analysis of three sediment cores, one containing a transition from possible wetland to beach to terrestrial sediments dating between 12.9-11.7 ky cal BP, evidences landscape transitions near the beginning and end of the YD. The sub-bottom data revealed a layered channel which, combined with adjacent core dates, suggests preserved paleosurfaces from the YD or earlier. Such preservation demonstrates that the channel survived drowning enough to preserve information about southern California’s early humans and the climate and sea level changes they experienced.

This Resource is Part of the Following Collections

• SAA 2024: Individual Abstracts   •
• Society for American Archaeology 89th Annual Meeting, New Orleans, LA (2024)

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Record Identifiers

Abstract Id(s): 38937.0