A Studies on Stable Oxygen and Carbon Isotope Records and Acuomulation Rates in Core 8KL of the South China Sea from Oxygen Isotope Stage 6

Qian Jianxing

The data of δ¹⁸O and δ¹³C were measured fromplanktoric forarninifera for 4 species and benthic foraminifen for 2 species in piston core 8KL of the South China Sea(S. C. S.).The oxygen isotope records of planktoric and benthic foraminifen can be recognized stage 1~6 distinctly. A research on biostratigraphy of the planktonic forams indicated that the last appearance datum(LAD)of Globigerinoides ruber(pink) occured at oxygen isotope stage 5. 5(≈120ka). The curvres of planktonic carbon isotope composition clearly recorded two lightest events at 128ka (stage 5/6) and 12ka(stage 1/2),especially for 128ka. This phenomenon was discoverd in different cores such as SCS 15A and 15B in the southern part of S. C. S.,37KL in the northern part of S. C. S. and V 19一30 in the East Pacific Ocean as well as the cores in Mexico Gulf. Therefore,the two events might be existed in the whole ocean. Due to the lighter δ¹³C value was recorded in deeper planktomic furams, so it can be infered that the two lightest events refleeted on existence of welling watermasses from intermediate and bottom waters in transitional duration from glaciation interglaciation. In terms of the oxygen siotope records from planktonic forams, the dewelling water depth of planktonic foraminifera species from shallower to deeper was G. Tuber (pink ),G. Tuber and G. sacculifer in turn. Based on oxygen isotope geostratigraphic scale,the sedimentary rates and fluxes were calculated for each stage. The results show that the sedimental rates and fluxes are 2. 7cm/ka and 17. 6g/m²·yr for stage 1;1. 9cm/ka and 16. Og/m²·yr for stage 5;6. 7cm/ka and 57. 3g/m²·yr for stage 6,7. 2cm/ka and 59. Og/m²·yr for the last glaciation (stage 2,3,9).All in all,the sedimentary rates and fluxes in glacial times were much greater than that in interglacial ages.

A Studies on Stable Oxygen and Carbon Isotope Records and Acuomulation Rates in Core 8KL of the South China Sea from Oxygen Isotope Stage 6

Second Institute of Oceanography, SOA, Hangzhou

Publish Date: 1994-09-10

Abstract: The data of δ¹⁸O and δ¹³C were measured fromplanktoric forarninifera for 4 species and benthic foraminifen for 2 species in piston core 8KL of the South China Sea(S. C. S.).The oxygen isotope records of planktoric and benthic foraminifen can be recognized stage 1~6 distinctly. A research on biostratigraphy of the planktonic forams indicated that the last appearance datum(LAD)of Globigerinoides ruber(pink) occured at oxygen isotope stage 5. 5(≈120ka). The curvres of planktonic carbon isotope composition clearly recorded two lightest events at 128ka (stage 5/6) and 12ka(stage 1/2),especially for 128ka. This phenomenon was discoverd in different cores such as SCS 15A and 15B in the southern part of S. C. S.,37KL in the northern part of S. C. S. and V 19一30 in the East Pacific Ocean as well as the cores in Mexico Gulf. Therefore,the two events might be existed in the whole ocean. Due to the lighter δ¹³C value was recorded in deeper planktomic furams, so it can be infered that the two lightest events refleeted on existence of welling watermasses from intermediate and bottom waters in transitional duration from glaciation interglaciation. In terms of the oxygen siotope records from planktonic forams, the dewelling water depth of planktonic foraminifera species from shallower to deeper was G. Tuber (pink ),G. Tuber and G. sacculifer in turn. Based on oxygen isotope geostratigraphic scale,the sedimentary rates and fluxes were calculated for each stage. The results show that the sedimental rates and fluxes are 2. 7cm/ka and 17. 6g/m²·yr for stage 1;1. 9cm/ka and 16. Og/m²·yr for stage 5;6. 7cm/ka and 57. 3g/m²·yr for stage 6,7. 2cm/ka and 59. Og/m²·yr for the last glaciation (stage 2,3,9).All in all,the sedimentary rates and fluxes in glacial times were much greater than that in interglacial ages.

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Reference (9)

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A Studies on Stable Oxygen and Carbon Isotope Records and Acuomulation Rates in Core 8KL of the South China Sea from Oxygen Isotope Stage 6

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