地球学报2011，Vol.32Issue(6)：681-690,10.DOI:10.3975/cagsb.2011.06.05
鄂尔多斯盆地苏里格地区奥陶系马家沟组马五段白云岩的地球化学特征
Geochemical Characteristics of Dolomite from 5th Member of the Ordovician Majiagou Formation in Sulige Area, Ordos Basin
摘要
Abstract
The dolomite in the 5th Member of the Ordovician Majiagou Formation is a significant reservoir in Sulige area. The origin of the Ordovician Majiagou Formation has been a hot topic for many years. The trace element and carbon, oxygen, strontium isotope compositions of dolomite developed in this deposit were determined in this study. The results show that the content of manganese, sodium and strontium is low. Meanwhile,the values of isotopes of δ13C and δ18O in secondary void-filling dolomite are much similar to those of the dolomite and dolomitic breccia. The δ18O values of the dolomite are in the range of 0.81‰~5.68‰(averagely 3.442‰), lower than those of the Ordovician seawater. The 87Sr/86Sr ratio is higher than that of the Ordovician seawater. An analysis shows that the fluids that generated dolomite and void-filling dolomite might have come from the same fluid source. The negative values of δ18O of dolomite result probably from temperature effect of the burial process. The high values of 87Sr/86Sr may be explained by the hypothesis that metasomatic fluids came from or flew though aluminosilicate basal rock or siliciclastic rock, which had rich radioactive strontium. Those characteristics of dolomite from 5th Member of Majiagou Formation were probably formed in a burial environment.关键词
白云岩/微量元素/C、O、Sr同位素/马家沟组/苏里格地区Key words
dolomite/ trace element/ carbon, oxygen and strontium isotope/ Majiagou Formation/ Sulige region分类
天文与地球科学引用本文复制引用
赵卫卫,王宝清..鄂尔多斯盆地苏里格地区奥陶系马家沟组马五段白云岩的地球化学特征[J].地球学报,2011,32(6):681-690,10.基金项目
本文由国家自然科学基金项目(编号:41102083)、中国石油长庆油田分公司勘探开发研究院重点科技攻关项目(编号:H07155)、西安石油大学博士启动基金(编号:YS29030504)联合资助. （编号:41102083）
