TY - JOUR
T1 - Strontium and carbon isotope stratigraphy of the Late Jurassic shallow marine limestone in western Palaeo-Pacific, northwest Borneo
AU - Kakizaki, Yoshihiro
AU - Weissert, Helmut
AU - Hasegawa, Takashi
AU - Ishikawa, Tsuyoshi
AU - Matsuoka, Jun
AU - Kano, Akihiro
N1 - Funding Information:
Prof. Y. Isozaki (The University of Tokyo) and an anonymous reviewer provided comments that greatly helped us to improve the manuscript. Measurement of Sr isotope in this study was performed in the cooperative research program of Kochi Core Center (No. 09B040) with the support by Dr. K. Okamura (Kochi University) and Dr. K. Nagaishi (Marine Works Japan Ltd.). Analyses in ETH were financially supported by the Japan Society for the Promotion of Science (JSPS), through the Institutional Program for Young Researcher Overseas Visits proposed by Prof. S. Arai and Prof. S. Umino (Kanazawa University). We thank M. C. Strasser, S. E. Bishop, Dr. M. I. Millán (ETH), and Dr. M. Giorgioni (Australian National University) for assisting with the isotope measurements in ETH. Dr. M. Sone (Malaya University) provided useful information on fieldwork in Borneo Island. Y. Kakizaki was financially supported by the Sasakawa Scientific Research Grant from the Japan Science Society, and T. Hasegawa by JSPS KAKENHI Grant (No. 20340144 ).
PY - 2013/9/5
Y1 - 2013/9/5
N2 - Strontium and carbon isotope stratigraphy was applied to a 202m-thick shallow marine carbonate section within the Late Jurassic Bau Limestone at the SSF quarry in northwest Borneo, Malaysia, which was deposited in the western Palaeo-Pacific. Strontium isotopic ratios of rudist specimens suggest that the SSF section was formed between the latest Oxfordian (155.95Ma) and the Late Kimmeridgian (152.70Ma), which is consistent with previous biostratigraphy. The δ13Ccarb values of bulk carbonate range from -0.10 to +2.28% and generally show an increasing upward trend in the lower part of the section and a decreasing upward trend in the upper part of the section. A comparable pattern is preserved in the δ13Corg isotope record. Limestone samples of the SSF section mainly preserve the initial δ13Ccarb values, except for the interval 84-92m, where an apparent negative anomaly likely developed as a result of meteoric diagenesis. Comparing with the Tethyan δ13Ccarb profile, a negative anomaly in the lower SSF section can be correlated with the lowered δ13C values around the Oxfordian/Kimmeridgian boundary. In addition, δ13Ccarb values of the Bau Limestone are generally ~1% lower than the Tethyan values, but comparable with the values reported from Scotland and Russia, located in Boreal realm during the Late Jurassic. This suggests that either the Tethyan record or the other records have been affected by the δ13C values of regionally variable dissolved inorganic carbon (DIC). The Late Jurassic δ13CDIC values are thought to have been regionally variable as a result of their palaeoceanographic settings. This study shows that δ13C chemostratigraphy of the Palaeo-Pacific region contributes to an improved understanding of global carbon cycling and oceanography during this time period.
AB - Strontium and carbon isotope stratigraphy was applied to a 202m-thick shallow marine carbonate section within the Late Jurassic Bau Limestone at the SSF quarry in northwest Borneo, Malaysia, which was deposited in the western Palaeo-Pacific. Strontium isotopic ratios of rudist specimens suggest that the SSF section was formed between the latest Oxfordian (155.95Ma) and the Late Kimmeridgian (152.70Ma), which is consistent with previous biostratigraphy. The δ13Ccarb values of bulk carbonate range from -0.10 to +2.28% and generally show an increasing upward trend in the lower part of the section and a decreasing upward trend in the upper part of the section. A comparable pattern is preserved in the δ13Corg isotope record. Limestone samples of the SSF section mainly preserve the initial δ13Ccarb values, except for the interval 84-92m, where an apparent negative anomaly likely developed as a result of meteoric diagenesis. Comparing with the Tethyan δ13Ccarb profile, a negative anomaly in the lower SSF section can be correlated with the lowered δ13C values around the Oxfordian/Kimmeridgian boundary. In addition, δ13Ccarb values of the Bau Limestone are generally ~1% lower than the Tethyan values, but comparable with the values reported from Scotland and Russia, located in Boreal realm during the Late Jurassic. This suggests that either the Tethyan record or the other records have been affected by the δ13C values of regionally variable dissolved inorganic carbon (DIC). The Late Jurassic δ13CDIC values are thought to have been regionally variable as a result of their palaeoceanographic settings. This study shows that δ13C chemostratigraphy of the Palaeo-Pacific region contributes to an improved understanding of global carbon cycling and oceanography during this time period.
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U2 - 10.1016/j.jseaes.2013.04.020
DO - 10.1016/j.jseaes.2013.04.020
M3 - Article
AN - SCOPUS:84878245858
VL - 73
SP - 57
EP - 67
JO - Journal of Asian Earth Sciences
JF - Journal of Asian Earth Sciences
SN - 1367-9120
ER -