Records of Toba eruptions in the South China Sea——Chemical characteristics of the glass shards from ODP 1143A  

作　　者：梁细荣 韦刚健 邵磊 李献华 王汝成 

出　　处：《Science China Earth Sciences》2001年第10期871-878,共8页中国科学（地球科学英文版）

基　　金：the NSFC, the National Natural Science Foundation of China (Grant No. 49999560).

摘　　要：Three layers of volcanic tephra, sampled from ODP 1143 Site in the South China Sea, were observed at the mcd depth of 5.55 m, 42.66 m, and 48.25 m, and named, in this paper, layers of A, B, and C, respectively. All of these tephra layers have an average thickness of ca. 2 cm. They were constrained in age of ca. 0.070 Ma, ca. 0.80 Ma, and ca. 1.00 Ma, respectively, by the microbiostratigraphy data. These tephra layers were predominated by volcanic glass shards with a median grain size of 70-75μm in diameter. Major chemical compositions analyzed by EMPA and comparison with the previous data from other scatter areas suggest that these three layers of tephra can correspond to the three layers of Toba tephra, YTT, OTT, and HDT, respectively, erupting during the Quaternary. The occurrence of these tephra layers in the South China Sea implies that the Toba eruptions often occurred in the summer monsoon seasons of the South China Sea during the Quaternary, and that the strength of eruptions was probably stronger than that previously estimated.

关 键 词：South China Sea ODP 1143 Site tephra shards Toba eruptions monsoon. 

分 类 号：P736.4[天文地球—海洋地质]