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通过分析目前寒武系已有的δ13C数据,从中至少可筛选出4次具有跨板块对比潜力的碳同位素漂移事件.由下至上标定为:(1)寒武系底界幅度介于4‰～10‰的负漂移,相当于“BACE”;(2)纽芬兰统幸运阶之顶至第2阶底,幅度大于5‰的正漂移,相当于“ZHUCE”;(3)第二统与第三统界线处δ13C最小值为-3‰～-5‰的负漂移,对比为“ROECE”;(4)芙蓉统排碧阶底部幅度约4‰的正漂移——“SPICE”.这4期碳同位素漂移与海洋环境重大变化及其引发的生物演化事件在时间上存在关联性,表现为:“BACE”与同期的大洋缺氧事件以及艾迪卡拉纪生物灭绝事件对应;“ZHUCE”与扬子地台第3小壳化石组合带对应;“ROECE”与同期三叶虫绝灭及海进事件对应;“SPICE”则与同期三叶虫绝灭及海退事件对应.另有一些源于区域剖面的漂移,其是否具有大区之间的对比意义,尚需对不同板块的同时代地层做更多的数据测试方可定论.
By analyzing the existing δ13C data in the Cambrian, at least 4 carbon isotope drift events with cross-plate contrast potentials can be screened from at least. (1) The bottom boundary of Cambrian is between 4 ‰ ~ The negative drift of 10 ‰ corresponds to “BACE ”; (2) The positive drift at the top of the Newfoundland from the top to the second, amplitude> 5 ‰ corresponds to “ZHUCE ”; (3) The negative drift of δ13C at the boundary between the second system and the third system is -3 ‰ ~ -5 ‰, and the comparison is “ROECE”. (4) The positive drift of the 4% “SPICE.” These four carbon isotope shifts correlate in time with the major changes in the marine environment and the events that triggered them, as follows: “BACE” and the oceanic anoxic events of the same period, Corresponding to the biological extinction event; “ZHUCE” corresponds to the third small fossil assemblage of the Yangtze platform; “ROECE” corresponds to the extinction and seaborne incursion of the trilobite in the same period; “SPICE” The extinction and retreat of the leafworms correspond to other events, while some of them originate from the regional profile drift. Whether it has the significance of contrast between the large regions or not, it still needs to do more data tests on the contemporaneous strata of different plates The trial can be finalized.