第29卷第1期 2015年2月
现代地质 GEOSCIENCE
南海神狐海域MIS12期以来的碳酸盐
旋回与水合物分解
陈芳，庄畅，周洋，吴聪，陆红锋，
刘坚，苏新，刘广虎
（1.国土资源部海底矿产资源重点实验室，广州海洋地质调查局，广东广州510075；
2.中国地质大学（北京）海洋学院，北京100083）
Vol. 29No. 1
Feb.2015
摘要：对南海神狐海域水合物钻探区SH1B和SH5C等2个钻孔顶部0~39.41m和0~23.85m的连续沉积物开展高分辨率碳酸盐旋回研究，结合浮游有孔虫氧同位素地层学、AMS4C年代学和生物地层学进行地层划分。结果表明：SH1B 孔MIS12期以来CaCO，曲线总体上具有明显的冰期和间冰期旋回，表现为较典型的冰期低、间冰期高的“大西洋型"旋回特征，具有良好的地层意义；SH5C孔除MIS1一MIS2期外，MIS3一MIS8期的CaCO，含量较SH1B孔的要低，冰期和间冰期旋回性较差，MIS3一MIS4和MIS7期出现明显的低钙事件；同时，SH5C孔MIS3一MIS5期浮游有孔虫G.ruber的 s"C值明显负偏，平均值为-0.11%e；两孔MIS1期的沉积速率是MIS2期的近2倍，与前人的研究结果相反，为MIS2 期部分地层缺失所致。SH1B孔受水合物分解影响不大，而SH5C孔受水合物分解影响明显。SH5C孔MIS2期的地层缺失事件和MIS3一MIS4、MIS7期的低钙事件以及MIS3一MIS5期s"C值负偏事件主要发生在末次冰期，推测与下伏水合物分解产生的海底滑塌、海水酸化等环境效应有关。
关键词：低钙事件；地层缺失；水合物分解；神狐水合物钻探区；南海
中图分类号：TE132.2；TE122.1
文献标志码：A
文章编号：10008527(2015)01014510
Carbonate Cycles and Gas Hydrate Dissociation in Shenhu Area
of the South China Sea since MIS12 Stage
CHEN Fang'ZHUANG Chang',ZHOUYang，WU Cong，LU Hong-feng'，
LIU Jian', SU Xin’, LIU Guang-hu'
(1. Key Laboratory of Marine Mineral Resources, Ministry of Land and Resources, Guangzhou Marine Geological Suey, Guangzhou,
Guangdong 510075, Ching; 2. School of Marine Geosciences, China Unirersity of Geosciences, Beijing 100083, China)
Abstract: A research on the high-resolution carbonate cycles of sediments has been accomplished, which were continuously derived from the top 39. 41-meter core of hole SH1B (261. 86 m) and the top 23. 85-meter core of hole SH5C (175. 17 m) in Shenhu gas hydrate drilling area of South China Sea, and then the analytical results were used to delimit the stratigraphic stages of SHIB and SH5C combined with oxygen isotopic stratigraphy of planktonic foraminifera, AMs '*C chronology and biological stratigraphy. The CaCO, curve of hole SHIB reveals apparent glacial-interglacial cycles since MIS12 and shows representative ‘ Atlantic-type' cycles which are char-acterized by low contents in glaciations and high contents in interglaciations, and it possesses stratigraphic sig-nificance. Compared to hole SH1B, the CaCO, content of hole SH5C is lower during MIS3 to MIS8 except MIS1 and MIS2, and the characteristics of glacial-interglacial cycles were not evident with less oscillations. The carbonate minimum (CM) in stages of MIS3 to MIS4 and MIS7 has been recognized in hole SH5C, meanwhile,
收稿日期：2014-11-01；改回日期：2014-12-30：责任编辑：潘令枝。
基金项目：国家自然科学基金项目（41372012）；国家专项项目（GZH2011003050602）。
作者简介：陈芳，女，教授级高级工程师，1966年出生，地层古生物专业，主要从事微体古生物学和水合物研究。
Email; zhchenfang66@ 21en. com。