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杨杰东1 2， 张俊明3， 陶仙聪1， 王宗哲3
摘要： 测定了云南永善肖滩前寒武系-寒武系界限Sr同位素组成及湖北省三峡 剖面震旦系碳酸盐岩Sr、C同位素组成，并与蒙古、 加拿大、西伯利亚和纳米 比亚的末元古系Sr和C同位素数据进行了比较，得出末元古纪海水87Sr/86Sr和 δ13C值的演变图。通过该演变图，可以对全球末元古系地层进行对比。
Abstract: Sr isotopes of limestones for the Precambrian-Cambrian boundary from the Xiaotan section, Yongshan, Yunnan province, and Sr and C is otope s of carbonates for the Sinian System from the Sanxia section, Hubei province have been investigated. The results were compared with the Sr and C isotopic data der ived from Mongolia, Canada, Siberia and Namibia. A variation curve of 8 7Sr/86Sr and δ13C for the seawater of the terminal Proterozo ic was pr oposed.
Just before the terminal Proterozoic, the δ13C value of seawater was high , about +11‰, and the 87Sr/86Sr was about 0.7072. At the period o f glaciation corresponding to the Nantuo/Ice Brook, the δ13C value of sea water was negative, about -5‰, and the 87Sr/86Sr was about 0.7 077. Later on, the δ13C value rapidly rose with at least three fluctuations. At the time corresponding to the Dengying formation, the δ13C value showed a flat terrace about +2～+3‰, and the 87Sr/86Sr about 0.7084. At t he Precambrian-Cambrian boundary, the δ13C value rapidly rose from a neg ative value to about +6‰, and the 87Sr/86Sr kept at about 0.7084 .
From the variation curve of 87Sr/86Sr and δ13C for seawater proposed in the present study, the strata of the terminal Proterozoic in the world can be correlated with each other.
杨杰东 ， 张俊明， 陶仙聪， 王宗哲
XU Hui-fang. Investigation of Invisible Au in Au-bearing FeS2 Microcrystals from Carlin Gold Ore Deposit，Nevada, USA: TEM Study and Geochemical Modeling[J]. J4.