泰国呵叻盆地二叠系碳酸盐岩元素地球化学特征与古环境意义

采用电感耦合等离子体发射光谱和同位素质谱等测试方法,对泰国呵叻盆地中部二叠系浅海相碳酸盐岩进行了微量元素与碳氧同位素组成及指标分析,讨论了研究区二叠系沉积古环境及其与碳酸盐岩烃源岩发育的控制关系。通过δ~(13)C/δ~(18)O指标及Sr/Ba、V/Ni、V/(V+Ni)比值等综合判别表明,研究区二叠系帕诺考组碳酸盐岩浅水斜坡亚相以淡-微咸水为主,属弱氧化-弱还原环境。深水斜坡亚相位于浪基面以下,以半咸水-咸水为主,属于缺氧的还原环境,为有机质保存提供了有利条件,是研究区碳酸盐岩烃源岩发育的有利相带。

Geochemical characteristics and its paleo-environmental significance of Permian carbonate rocks in Khorat Basin,Thailand

Based on testing methods of ICP-AES and stable isotope mass spectrometry, the authors we analyzed the compositions of trace elements, carbon and oxygen isotopes of Permian carbonate rocks in Khorat Basin. Studies were also carried out on the palaeo-sedimentary environment and its significance for the development of carbonate source rocks in the studied area. The comprehensive examination of δ13C/δ18O, Sr/Ba, V/Ni, V/(V+Ni) results show that sedimentary environment in shallower slope sub-facies of the studied area is typically characterized by fresh-brackish water and weak oxidation-weak reduction environment. Deeper slope sub-facies located below the wave base is characterized by brackish-saline water, anoxic and reduction environment, which is favorable for the preservation of organic matter. Deeper slope sub-facies are confirmed to be more favorable for the development of carbonate source rocks in the studied area.