Research output: Contribution to journal › Article › peer-review
230 th-excess and 14 C dating of pelagic sediments from the hydrothermal zone of the North Atlantic. / Kuznetsov, V. Y.U.; Arslanov, K. A.; Shilov, V. V.; Cherkashev, G. A.; Chernov, S. B.
In: Geochronometria, Vol. 21, 01.01.2002, p. 33-40.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - 230 th-excess and 14 C dating of pelagic sediments from the hydrothermal zone of the North Atlantic
AU - Kuznetsov, V. Y.U.
AU - Arslanov, K. A.
AU - Shilov, V. V.
AU - Cherkashev, G. A.
AU - Chernov, S. B.
PY - 2002/1/1
Y1 - 2002/1/1
N2 - A comprehensive geochronological study of a pelagic sediment core altered by hydrothermal processes from the Mid Atlantic Ridge (14.5°N) was carried out using both the 230 Th excess and the radiocarbon methods. Complementary foraminiferal tests and oxygen-isotope determinations were done. The main task was to check whether 230 Th excess dating of such diagenetically changed sediments yields reliable absolute ages. For this purpose the vertical distribution of the 238 U, 234 U, 232 Th and 230 Th activities along the core was measured. The results proved that it was not disturbed during the aging of the sediment. The long-term hydrothermal influence had been constant during at least the last 300 ka and did not change the natural 230 Th excess distribution along the core. Hence, 230 Th excess dating yields reliable ages and allows to calculate sedimentation rate. Between the uppermost and lowermost sublayers of the core we obtained 1.35±0.15 cm/ka which agrees with 1.47±0.03 cm/ka derived from conventional 14 C ages. These numerical dates, the results of the foraminiferal tests and the 18 O values place the studied sediments to the marine isotope stage 5 (MIS 5). These dates are well correlated with the corresponding sedimentary records from pelagic sediments of the North Atlantic Ocean.
AB - A comprehensive geochronological study of a pelagic sediment core altered by hydrothermal processes from the Mid Atlantic Ridge (14.5°N) was carried out using both the 230 Th excess and the radiocarbon methods. Complementary foraminiferal tests and oxygen-isotope determinations were done. The main task was to check whether 230 Th excess dating of such diagenetically changed sediments yields reliable absolute ages. For this purpose the vertical distribution of the 238 U, 234 U, 232 Th and 230 Th activities along the core was measured. The results proved that it was not disturbed during the aging of the sediment. The long-term hydrothermal influence had been constant during at least the last 300 ka and did not change the natural 230 Th excess distribution along the core. Hence, 230 Th excess dating yields reliable ages and allows to calculate sedimentation rate. Between the uppermost and lowermost sublayers of the core we obtained 1.35±0.15 cm/ka which agrees with 1.47±0.03 cm/ka derived from conventional 14 C ages. These numerical dates, the results of the foraminiferal tests and the 18 O values place the studied sediments to the marine isotope stage 5 (MIS 5). These dates are well correlated with the corresponding sedimentary records from pelagic sediments of the North Atlantic Ocean.
KW - Th-Excess dating
KW - Bio-Stratigraphy
KW - Geochronology
KW - Hydrothermal Activity
KW - Oxygen-Isotope Stratigraphy
KW - Pelagic Sediment
KW - Radiocarbon Dating
UR - http://www.scopus.com/inward/record.url?scp=33749156534&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:33749156534
VL - 21
SP - 33
EP - 40
JO - Geochronometria
JF - Geochronometria
SN - 1733-8387
ER -
ID: 49070157