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在塔河油田S112-1井中奥陶世—晚奥陶世已建立的牙形石生物地层框架内,对该井的124件碳酸盐岩岩芯样品进行了碳同位素分析研究。发现本次所获得碳同位素值全部在正值区域,δ13 C最大值为+2.7‰,最小值为+0.2‰,平均值为+1.071‰。从一间房组至恰尔巴克组碳同位素表现出缓慢上升。在良里塔格组发现可进行全球对比的GICE正漂移事件,此发现丰富了塔里木盆地覆盖区的中奥陶世—晚奥陶世的碳同位素证据,进一步验证了GICE事件的全球性。在GICE正漂移事件之后,碳同位素值经过短暂的波动,稳定表现在+1‰附近振荡。该时期的碳同位素值的变化趋势与中晚奥陶世海平面变化具有相关性。
Within the framework of the established albite-Late Ordovician conodont in the S112-1 well of Tahe oilfield, carbon isotope analysis was performed on 124 carbonate core samples from this well. It is found that all the carbon isotope values obtained in this study are in the positive region, the maximum of δ13 C is + 2.7 ‰, the minimum is + 0.2 ‰, and the average is + 1.071 ‰. Carbon isotopes showed a slow increase from Yijiaji to Qiaerbuck. The discovery of a globally comparable GICE positive drift in the Lianglitage Formation enriched the carbon isotopic evidence of the Middle Ordovician-Late Ordovician in the Tarim Basin, further confirming the global nature of the GICE event. After the GICE positive drift event, the carbon isotope values fluctuated briefly, and the stable performance oscillated around + 1 ‰. The change trend of carbon isotope values in this period is related to the change of sea level in middle-late Ordovician.