Coastal plain stratigraphy records tectonic, environmental, and human habitability changes related to sea-level drawdown, ‘Upolu, Sāmoa
Autor: | Matthew M. Barbee, Ethan E. Cochrane, Haunani H. Kane, Shellie Habel, Jerry X. Mitrovica, Charles H. Fletcher |
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Rok vydání: | 2017 |
Předmět: |
education.field_of_study
geography geography.geographical_feature_category 010504 meteorology & atmospheric sciences Coastal plain Population Future sea level 010502 geochemistry & geophysics 01 natural sciences Oceanography Arts and Humanities (miscellaneous) General Earth and Planetary Sciences Sedimentology Progradation education Geomorphology Reef Sea level Geology Holocene 0105 earth and related environmental sciences Earth-Surface Processes |
Zdroj: | Quaternary Research. 87:246-257 |
ISSN: | 1096-0287 0033-5894 |
Popis: | Coastal plain stratigraphy is often over looked in paleo–sea-level reconstructions because carbonate sediments do not precisely constrain former sea level. Pacific Island sedimentology provides an invaluable record of geomorphic and environmental consequences of coastal evolution in response to changes in sea level and local tectonics. A series of coastal auger cores obtained from eastern ʻUpolu reveal a subsurface carbonate sand envelope predominately composed of coral and coralline algae derived from the reef framework. Coupling the sedimentological record with geophysical models of Holocene sea level, we identify a critical value (0.3–1.0 m) during the falling phase of the sea-level high stand (1899–2103 cal yr BP) that represents the transition from a transgressive to a regressive environment and initiates coastal progradation. Correlating the critical value with time, we observe nearly a millennium of coastal plain development is required before a small human population is established. Our findings support previous studies arguing that Sāmoa was colonized by small and isolated groups, as post–mid-Holocene drawdown in regional sea level produced coastal settings that were morphologically attractive for human settlement. As future sea level approaches mid-Holocene high stand values, lessons learned from Pacific Island sedimentological records may be useful in guiding future decisions related to coastal processes and habitat suitability. |
Databáze: | OpenAIRE |
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