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西藏南部上白垩统半远洋沉积高分辨率碳、氧同位素实验结果显示δ13C值在Cenomanian末期正偏并形成正偏“高原”,从Turonian期开始总体呈现长期持续负偏,到Campanian早期负偏达到最低值。这种长期变化格局与世界有关地区的碳同位素偏移和同期全球海侵—海退旋回型式匹配性甚好,印证了晚白垩世δ13C值长期偏移趋势可作为大区域乃至全球海平面变化的指针。短期δ13C值波动方面,Cenomanian末期、Turonian中—晚期、Turoni-an—Santonian界线时期、Campanian期都存在与世界相关地区的可比性,但Coniacian—Santonian期全球碳同位素偏移型式存在较大差异。
The results of high-resolution carbon and oxygen isotope analyzes of the sediments of the Upper Cretaceous in southern Tibet show that the δ13C values are positive and negative in the Cenomanian end and form a long-term negative bias from the Turonian to the early Campanian negative Lowest value. This pattern of long-term variation has a good match with the carbon isotope shifts of the world-related regions and the global transgression-regression cyclonic pattern of the same period, which confirms that the long-term δδδC deviation trend of the Late Cretaceous can be used as a sea level change in large regions and even in the world pointer. In terms of short-term δ13C fluctuations, the Cenomanian period, the mid-late Turonian period, the Turoni-an-Santonian boundary period and the Campanian period have comparability with the world-related areas. However, the global carbon isotope offset types in the Coniacian-Santonian period are quite different.