Publication Date:
2021-07-09
Description:
EXTRACT (SEE PDF FOR FULL ABSTRACT):Pollen analysis and 5 radiocarbon dates for a 687-cm core provide a detailed chronology of environmental change for San Joaquin Marsh at the head of Newport Bay, Orange County, California. Sediment deposition kept pace with sea level rise during the mid-Holocene, but after 4500 years BP, sea water regularly reached the coring site, and salt marsh was the local vegetation. Brief periods of dominance by fresh-water vegetation 3800, 2800, 2300 and after 560 years BP correlate global cooling events and (except the 3800-year BP event) with carbon-14 production anomalies. The coincidence of climate change and carbon-14 anomalies support a causal connection with solar variability, but regardless of the causal mechanism(s) the delta-carbon-14 curves provide a chronology for global, high-frequency climatic change comparable to that of Milankovitch cyclicity for longer time scales.
Keywords:
Atmospheric Sciences
;
Earth Sciences
;
Ecology
;
PACLIM
;
palynology
;
dendrochronology
Repository Name:
AquaDocs
Type:
conference_item
Format:
application/pdf
Format:
application/pdf
Format:
19-33
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