AMS 14C dating of Holocene estuarine deposits: consequences of high energy and reworked foraminifera
AMS 14C dating of Holocene estuarine deposits: consequences of high energy and reworked foraminifera
Benthic foraminiferal species were used to AMS date Holocene sediments adjacent to trangressive overlap boundaries (TOB) in two high-energy estuaries in northern Spain. It had previously been recognized that the foraminifera could be divided into indigenous and exotic components. Whereas it was known that the exotic forms had been transported into the estuaries from the adjacent inner shelf, it was assumed that the indigenous forms were in situ. The AMS dates based on indigenous forms obtained from pairs of samples adjacent to the TOB showed an inverse relationship in three out of four boreholes (i.e., the age of the higher sample was older than that of the lower). The most probable explanation of this unexpected result is that there had been significant reworking of indigenous foraminifera especially associated with the transgressive episode. It is concluded that, in high energy estuaries, AMS dating on foraminiferal shells is influenced by transport and reworking even of the indigenous component. Therefore, if only foraminifera are available for dating, we recommend that closely spaced pairs of samples should be dated in order to assess the reliability of the results.
Benthic foraminifera, Holocene, northern Spain, estuaries, transgressive overlap boundaries, AMS radiocarbon dates
155-159
Cearreta, A.
9be57952-6999-443b-a045-1a064e57bbd3
Murray, J.W.
3985aa41-1e0e-4504-ab90-e31a00c33c38
2000
Cearreta, A.
9be57952-6999-443b-a045-1a064e57bbd3
Murray, J.W.
3985aa41-1e0e-4504-ab90-e31a00c33c38
Cearreta, A. and Murray, J.W.
(2000)
AMS 14C dating of Holocene estuarine deposits: consequences of high energy and reworked foraminifera.
The Holocene, 10 (1), .
Abstract
Benthic foraminiferal species were used to AMS date Holocene sediments adjacent to trangressive overlap boundaries (TOB) in two high-energy estuaries in northern Spain. It had previously been recognized that the foraminifera could be divided into indigenous and exotic components. Whereas it was known that the exotic forms had been transported into the estuaries from the adjacent inner shelf, it was assumed that the indigenous forms were in situ. The AMS dates based on indigenous forms obtained from pairs of samples adjacent to the TOB showed an inverse relationship in three out of four boreholes (i.e., the age of the higher sample was older than that of the lower). The most probable explanation of this unexpected result is that there had been significant reworking of indigenous foraminifera especially associated with the transgressive episode. It is concluded that, in high energy estuaries, AMS dating on foraminiferal shells is influenced by transport and reworking even of the indigenous component. Therefore, if only foraminifera are available for dating, we recommend that closely spaced pairs of samples should be dated in order to assess the reliability of the results.
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Published date: 2000
Keywords:
Benthic foraminifera, Holocene, northern Spain, estuaries, transgressive overlap boundaries, AMS radiocarbon dates
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Local EPrints ID: 403
URI: http://eprints.soton.ac.uk/id/eprint/403
ISSN: 0959-6836
PURE UUID: 76a124bd-7283-4b7f-957a-3da7c6190975
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Date deposited: 25 Mar 2004
Last modified: 15 Mar 2024 04:41
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Author:
A. Cearreta
Author:
J.W. Murray
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