地质科学2018，Vol.53Issue(2)：458-469,12.DOI:10.12017/dzkx.2018.025
鄂尔多斯盆地南缘铜川地区三叠系延长组油页岩中“钙质结核”的成因初探
A preliminary discussion on the origin of "calcareous concretion" in oil shale of Yanchang Formation in Tongchuan area, southern Ordos Basin
摘要
Abstract
Some "calcareous concretion" were found in the oil shale of Chang 7 section of Yanchang Formation in the outcrops of the Tongchuan area,the southern part of the Ordos Basin.These "calcareous concretion" were layered developed in the oil shale of the Chang 7 section in the outcrops,in the form of "lenticular","ellipsoid","discoid",about 10 ～ 70 cm in diameter.In order to identify the rock type and main rock components,the petrological characteristics of these concretion were analyzed by microscope observation of section,electron microprobe experiment and EDS analysis.On this basis,the origin of these "calcareous concretion" were preliminarily discussed.The "calcareous concretion" in Bawangzhuang and Taotan field section of Tongchuan area are mainly composed of recrystallised calcite and crystalline calcite,with "globular" structure,and its rock type is limestone.The rock type of "calcareous concretion" in Niejiahe field section are silt-micrite dolostone.The results show that these "calcareous concretion" in the field occurence and the composition of the rocks meet the characteristics of hydrothermal exhalative deposition of carbonate rocks and hydrothermal activities.And the Tongchuan area had the condition of hydrothermal activity in the Chang 7 period.It is tentatively believed that these "calcareous concretion" are lacustrine carbonate rocks that contribute to the hydrothermal activity.关键词
鄂尔多斯盆地/铜川地区/延长组/油页岩/湖相碳酸盐岩/热液活动/热水沉积/碳酸盐岩Key words
Ordos Basin/Tongchuan area/Yanchang Formation/Oil shale/Lacustrine carbonate rocks/Hydrothermal activity/Hydrothermal sedimentary carbonate rocks分类
天文与地球科学引用本文复制引用
马瑶,李文厚,刘江斌,李智超..鄂尔多斯盆地南缘铜川地区三叠系延长组油页岩中“钙质结核”的成因初探[J].地质科学,2018,53(2):458-469,12.基金项目
国家自然科学青年基金项目(编号:41702117)、国家自然科学重点基金项目(编号:41330315)和陕西省自然科学基础研究青年项目(编号:2017JQ4018)资助. （编号:41702117）
