西安科技大学学报2025，Vol.45Issue(5)：1035-1043,9.DOI:10.13800/j.cnki.xakjdxxb.2025.0518
鄂尔多斯盆地东南缘长7地球化学特征和古环境-古气候条件
Geochemical characteristics and paleoenvironment-paleoclimate conditions of Chang 7 Member in southeastern margin of Ordos Basin
摘要
Abstract
In order to study the provenance input characteristics,paleosalinity changes,paleoclimate types and paleoredox conditions of the Chang 7 Member in Yijun area of the southeastern margin of the Ordos Basin during the sedimentary period,the paleoenvironment was restored by using handheld X-ray fluorescence spectrometer,elements and element ratios.The results show that the Fe/Ti ratio ranges from 15.49 to 17.14 during the sedimentary period of the Chang 7 Member,and a large number of ter-rigenous detritus are poured into the lake basin,in which the siliceous components are mainly terrige-nous detritus.The Zr/Al value is between 0.041～0.045.There is more terrigenous debris input in the sedimentary period of the Chang 72 submember,and the sedimentary area is closer to the source area at this time,while the terrigenous input is less in the sedimentary period of the Chang 73 and Chang 71 submembers.The Sr/Ba values range from 0.29 to 0.33,and the water environment during the sedi-mentary period of the Chang 7 Member is dominated by brackish water,and only the paleosalinity shows an upward trend during the Chang 72 sub-member.The Sr/Cu values range from 3.52 to 13.83,and combined with the mirror evolution of Rb/Sr values,the climate type of the Chang 7 sedimentary period is mainly warm and humid climate,and only in the Chang 72 sub-period it is hot and dry.The V/(V+Ni)value is between 0.57～0.68,and the sedimentary environment is dominated by anoxic re-ducing environment.The results provide geochemical evidence for the sedimentary environment of the Chang 7 Member in the southeastern margin of Ordos Basin,which is helpful to further explore the sed-imentary evolution process and paleoenvironmental response mechanism of the Chang 7 Member,and has reference significance for the paleoclimate evolution of different inland basins.关键词
长7段/黑色页岩/古环境/延长组/鄂尔多斯盆地Key words
Chang 7 Member/black shale/paleoenvironment/Yanchang Formation/Ordos Basin分类
天文与地球科学引用本文复制引用
曹纪港,李继宏,武晓玥,张忠义,宋依晖,李硕,杨堪阳,段亮..鄂尔多斯盆地东南缘长7地球化学特征和古环境-古气候条件[J].西安科技大学学报,2025,45(5):1035-1043,9.基金项目
国家自然科学基金项目(42242201) （42242201）
