Research on Carbon and Oxygen Geochemistry of Lower Paleozoic in North China
Research on Carbon and Oxygen Geochemistry of Lower Paleozoic in North China
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发表时间：
2002
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通讯作者：
Wang Darui
中科院分区：
文献类型：
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作者：
Wang Darui
A research of stable isotopic composition of carbonates from both standard sections of the Cambrian located at Zhangxia, Shandong Province and those of the Ordovician at Tangshan, Hebei Province, both in North China, shows that the δ18O values range from -10. 6‰ to -4. 8‰ and the δ13C values, between -5. 8‰ and + 1. 6‰ in the Cambrian; and the δ13O values range between -15. 9‰ and -6. 0‰ and, -7. 6‰ to + 1. 2‰ in the Ordovician. The positive shift of the δ13C values does not appear as occurs in Ordovician sections of South China and the Tarim Basin, and also in the sections of North America and Switzerland, suggesting that strata of the Llandeilo stage (and above) were absent in North China. The abnormal shifts of carbon iso-topic composition can be found between the palaeontological zones in the Ordovician, so the isotopic curves can be used as a tool for stratigraphical division and correlation in a large area. Based on correlative studies of the Ordovician System in North China, the Tarim Basin and South China, the obvious positive shift of carbon iso-topes can be a macroscopic geochemical index for the generation of source rocks in geological history.
