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对宁夏贺兰山地区出露的震旦系碳酸盐岩进行了详细的野外地质调查和碳氧同位素分析测试,发现该地区震旦系正目观组碳酸盐岩碳同位素表现出一定的变化规律:由北到南的几条典型剖面中δ13C值自下向上均逐渐减小,变化范围都集中在4.51‰~0.11‰,最大负偏值达到了6.88‰.兔儿坑组中发现的宏体生物化石在华南灯影组中部出现,从而将正目观组和兔儿坑组的形成时代限定在震旦纪.冰川的发育导致了极端寒冷的气候,海洋中有机质大幅降低,δ13C值出现普遍的负偏.兔儿坑组代表了冰期的结束,生物的复苏,海洋中有机物含量增加.通过与全球其他地区同期地层碳氧同位素分布的投图对比,发现正目观组冰期沉积的形成时间可能晚于Gaskiers冰期,研究其为探讨埃迪卡拉纪华北板块的古海洋、古地理环境和生物演化起了重要作用,为全球同期地层碳氧同位素数据库提供了新的补充.
A detailed field geologic survey and carbon and oxygen isotope analysis of Sinian carbonate rocks exposed in the Helan Mountain area of Ningxia were carried out. It was found that the carbon isotopic composition of the Carbonate rocks in the Zhenguan Formation of the Sinian in the area showed some changes : The δ13C values of several typical sections from north to south gradually decrease from bottom to top, with the range of variation being 4.51 ‰ ~ 0.11 ‰ and the maximum negative bias value reaching 6.88 ‰. The macro-bodies The biological fossils appeared in the middle of the Dengan Formation in South China, thus limiting the age of the Mesozoa and Turen Formation to the Sinian. The development of the glaciers led to an extremely cold climate with a significant decrease of δ13C values Negative deviation.The Taulet Formation represents the end of the glacial period, the recovery of the organism, and the increase of the organic matter content in the ocean.Comparing with the mapping of the stratigraphic carbon and oxygen isotope distribution in other parts of the world, it is found that the formation time of the glacial deposition in the Gazian Formation may be Later than the Gaskiers glacial period, it was studied to play an important role in exploring the paleoceanic, paleogeographic environment and biological evolution of the Edith Calanderhous plate, and to provide a global carbon and oxygen isotope database for stratigraphy over the world The new supplement.