浙江煤山长兴阶有机碳δ^(13)C层序分布特征及古气候意义  

Stratigraphic Distribution and Paleoclimatic Significance of Organic Canbon δ^(13)C in the Changxing Stage of Meishan, Zhejiang

作　　者：王万春[1] 李玉成[2] 

机构地区：[1]中国科学院兰州地质研究所气体地球化学国家重点实验室,730000 [2]南京大学地球科学系,210093

出　　处：《地质论评》1999年第4期368-374,共7页Geological Review

基　　金：中国科学院留学经费择优支持回国工作基金

摘　　要：本文通过对浙江长兴煤山D剖面长兴阶56个样品的沉积有机碳碳同位素(δ^(13)C_(org))分析,讨论了长兴期沉积有机碳δ^(13)C_(org)在地层层序分布上的特征,及其与海水进退和碳酸盐岩δ^(13)C_(carb)及δ^(18)O_(carb)之间的关系。浙江煤山D剖面长兴阶δ^(13)C_(org)在地层层序上的分布总体呈现自下而上由重变轻的趋势,同时,δ^(13)C_(org)层序分布与生物演化及δ^(13)C_(carb)和δ^(18)C_(carb)层序分布之间具有对应关系。长兴期中国南方海相沉积有机质δ^(13)C_(org)相对于现代海相沉积有机质δ^(13)C_(org)偏轻3‰～7‰,造成这一现象的主要原因可能是晚二叠世全球大范围的海退和火山活动所引起的大气及海水中CO_2含量的升高。Analysis of the carbon isotopic composition of sedimentary organic carbon of 56 samples in the Changxing Stage from the D section of Meishan, Changxing, Zhejiang, indicates that in terms of the stratigraphic distribution, depositional organic carbon δ13Corg in the Changxing Stage has a tendency to become lighter from below upward at the D section of Meishan and is also related to the rise and fall of the sea level. There is a correlation between the stratigraphic distributions of δ13Corg and δ13Ccarb in the Changxing Stage, that is, when δ13Corg become lighter δ13Ccarb become heavier, and vice versa. The stratigraphic distribution of δ13Corg of the Changxing Stage corresponds to the biological evolution and δ13Ccarb and δ18Ocarb cyclostratigraphy of the Changxing Stage at the D section of Meishan, Changxing, indicating that the δ13Corg value also has certain significance in stratigraphic classification and correlation. The δ13C value of marine organic carbon in the Changxing Stage in southern China is 3‰o to 7‰ lighter that of modern marine depositional organic matter, this was principally due to the high concentration of CO2 in ocean and atmosphere brought about by global marine regression and vocanic activities during the Changxing Stage.

关 键 词：沉积有机碳 碳同位素 层序分布 长兴期 古气候 

分 类 号：P532[天文地球—古生物学与地层学] P597[天文地球—地质学]