In:
Quaternary Research, Cambridge University Press (CUP), Vol. 52, No. 2 ( 1999-09), p. 206-216
Abstract:
Radiocarbon accelerator mass spectrometric (AMS) dates on the acid-insoluble fraction from 38 core tops from the western Ross Sea, Antarctica, are used to address these questions: (1) What are the apparent ages of sediments at or close to the present sediment/water interface? (2) Is there a statistically significant pattern to the spatial distribution of core top ages? and (3) Is there a “correction factor” that can be applied to these age determinations to obtain the best possible Holocene (downcore) chronologies? Ages of core top sediments range from 2000 to 21,000 14 C yr B.P. Some “old” core top dates are from piston cores and probably represent the loss of sediment during the coring process, but some core top samples 〉 6000 14 C yr B.P. may represent little or no Holocene deposition. Four possible sources of variability in dates ≤6000 14 C yr B.P. ( n = 28) are associated with (1) different sample preparation methods, (2) different sediment recovery systems, (3) different geographic regions, and (4) within-sample lateral age variability. Statistical analysis on an a posteriori design indicates that geographic area is the major cause of variability; there is a difference in mean surface sediment age of nearly 2000 yr between sites in the western Ross Sea and sites east of Ross Bank in south-central Ross Sea. The systematic variability in surface age between areas may be attributed to: (a) variable sediment accumulation rates (SAR) (surface age is inversely related to SAR), (b) differences in the percentage of reworked ( dead ) carbon between each area, and/or (c) differences in the CO 2 exchange between the ocean and the atmosphere.
Type of Medium:
Online Resource
ISSN:
0033-5894
,
1096-0287
DOI:
10.1006/qres.1999.2047
Language:
English
Publisher:
Cambridge University Press (CUP)
Publication Date:
1999
detail.hit.zdb_id:
1471589-2
detail.hit.zdb_id:
205711-6
SSG:
13
SSG:
14
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