TY - JOUR
T1 - Identification of diagenetic artifacts in foraminiferal shells using carbon and oxygen isotopes
AU - Shieh, Ying Tzung
AU - You, Chen Feng
AU - Shea, Kai Shuan
AU - Horng, Chorng Shern
N1 - Funding Information:
Two anonymous reviewers are most sincerely thanked for their invaluable comments. We are also grateful acknowledge M.A. Hall for assistance with the laboratory work at the Godwin Laboratory, University of Cambridge. This study was financially supported by the National Science Council of the Republic of China under grant NSC88-2611-M-115-001-ODP and NSC89-2611-M-115-002-ODP to Y.-T. S.
PY - 2002/11/30
Y1 - 2002/11/30
N2 - We have analyzed carbon and oxygen isotopes of two groups of planktonic foraminiferal shells from sediments near the Pliocene/ Pleistocene (P/P) and the Miocene/Pliocene (M/P) boundaries, in the Lower Gutingkeng Formation in southwestern Taiwan. The P/P shells display heavier isotopic compositions (δ18O = -1.5‰, δ13C = 1.5‰) over a narrow range, suggesting a pristine environmental signature. On the other hand, the M/P shells are much lighter (δ18O = -3 to -7‰, δ13C = 1 to -1.5‰), and more scattered, associated with secondary carbonate diagenesis. Our detailed SEM examination confirms this proposition. The P/P shells display a clean micro-texture and are free from carbonate recrystallization. However, there are abundant secondary calcite crystals in the M/P shells. Therefore, the extreme shift of δ18O and δ13C in foraminiferal shells provides a guideline for evaluation of diagenetic artifacts of deeply buried sediments that have been uplifted on land.
AB - We have analyzed carbon and oxygen isotopes of two groups of planktonic foraminiferal shells from sediments near the Pliocene/ Pleistocene (P/P) and the Miocene/Pliocene (M/P) boundaries, in the Lower Gutingkeng Formation in southwestern Taiwan. The P/P shells display heavier isotopic compositions (δ18O = -1.5‰, δ13C = 1.5‰) over a narrow range, suggesting a pristine environmental signature. On the other hand, the M/P shells are much lighter (δ18O = -3 to -7‰, δ13C = 1 to -1.5‰), and more scattered, associated with secondary carbonate diagenesis. Our detailed SEM examination confirms this proposition. The P/P shells display a clean micro-texture and are free from carbonate recrystallization. However, there are abundant secondary calcite crystals in the M/P shells. Therefore, the extreme shift of δ18O and δ13C in foraminiferal shells provides a guideline for evaluation of diagenetic artifacts of deeply buried sediments that have been uplifted on land.
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U2 - 10.1016/S1367-9120(01)00083-9
DO - 10.1016/S1367-9120(01)00083-9
M3 - Article
AN - SCOPUS:0037202639
SN - 1367-9120
VL - 21
SP - 1
EP - 5
JO - Journal of Asian Earth Sciences
JF - Journal of Asian Earth Sciences
IS - 1
ER -