石油实验地质2018，Vol.40Issue(2)：210-217,8.DOI:10.11781/sysydz201802210
川东北旺苍地区栖霞组地球化学特征及其古环境意义
Geochemical characteristics and paleo-environmental implications of Middle Permian Qixia Formation in Wangcang, northern Sichuan
摘要
Abstract
The sedimentary paleoenvironment of the Middle Permian Qixia Formation in northeastern Sichuan Basin was studied based on outcrop observations and laboratory analyses. The data correlations of the δ13C and δ18O of 19 samples from the Qixia Formation showed that there was no linear relationship between them.The samples are reliable targets for paleoenvironmental analyses since δ18O>-6‰,Mn/Sr≤0.6,Fe/Sr<3,and MgO/CaO<0.125.The contents of terrigenous elements(Al2O3and TiO2)are low, and are strongly and positively correlated. The ∑REE and∑(Al2O3+TiO2)also showed a positive relationship. The characteristics of other main and trace elements indicated that the Qixia Formation was formed in a hypoxic or oxygen-depleted environment. The Sr/Ba value ranges from 21.9-261.9,indicating that the sea level was relatively high,so the terrigenous material content is low,and the terri-genous detrital sediments were controlled by paleo-water depth during sedimentation.The carbon and oxygen isotopes revealed that the ancient oceanic temperature ranged from 17.62-28.43℃,the paleosalinity ranged from 129.07-135.21, and the ratio of MgO/CaO ranged from 0.007-0.029,revealing that the paleoenvironmental climate was relatively warm and humid. Water depth fluctuated within a small range and experienced two transgressive and regressive cycles.关键词
地球化学/沉积环境/碳酸盐岩/栖霞组/中二叠统/川东北Key words
geochemistry/sedimentary environment/carbonate rock/Qixia Formation/Middle Permian/north-eastern Sichuan分类
能源科技引用本文复制引用
张运周,徐胜林,陈洪德,林良彪,董翼昕,余瑜,张瑶..川东北旺苍地区栖霞组地球化学特征及其古环境意义[J].石油实验地质,2018,40(2):210-217,8.基金项目
国家自然科学基金青年科学基金项目(41602107)和成都理工大学中青年骨干教师培养计划(JXGG201537,JXGG201538)资助. （41602107）
