Habitat-Specific Marine Reservoir Corrections along the Central California Coast: The Effects of Differential Upwelling

Summary

This is an abstract from the "SAA 2019: General Sessions" session, at the 84th annual meeting of the Society for American Archaeology.

A confluence of natural factors has created three different ecological habitats for marine shellfish with potentially unique marine reservoir offsets along the central California coast. Deep-water trenches adjacent to the rocky points (e.g., Arguello, Conception, Sal), create localized upwelling environments. Reported offsets range from 400-1000 years for rock-dwelling species that comprise most shell middens. Sandy beaches dominating this section of shoreline were an historically important shellfish source formed by an offshore shelf; hypothesized to approximate average California coastal offsets (~225 years). Muddy lagoon species have yielded offsets of 90-150 years. The range of uncertainty between aquatic niches and terrestrial organics leaves sizable data gaps that could produce poor chronological precision and incidental evidence for extended habitations. Lowered sea levels would have brought the accessible coastline closer to these marine trenches potentially exacerbating the problem. Paired samples covering different ecological niches from twelve short-term archaeological sites were analyzed to gauge the offset(s) during primarily the late Holocene. Two main hypotheses are tested through this research: 1) quantify reservoir effects and determine appropriate ΔR values including any localized variance; and 2) outline the presence and extent of ecological niche-specific offset corrections needed for rocky shoreline, sandy beach, and lagoon shellfish species.

This Resource is Part of the Following Collections

• Society for American Archaeology 84th Annual Meeting, Albuquerque, NM (2019)

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Record Identifiers

Abstract Id(s): 25034