贵州碳酸盐岩风化壳形成年龄的初步判定
Primary Estimation of Forming Date for Carbonate Weathering Crust in Guizhou Province
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摘要: 贵州地区广泛分布的碳酸盐岩风化壳的直接测年一直未解决。本工作在前期研究基础上,利用裂变径迹法详细地对3个风化壳剖面中的次生石英颗粒进行年代学研究,以初步界定风化壳的形成时代。测试结果表明,新蒲风化壳剖面大约开始形成于距今8.5 Ma;官坝风化壳剖面大约开始形成于距今7.3 Ma;大兴风化壳剖面大约开始形成于距今4.6 Ma。Abstract: The problem of directed dating of carbonate weathering crust in Guizhou Province hasn’t been resolved. On the base of our previous study, we tested in detail the ages of antigenic quartz grains by fission track dating method and give a limitation of the forming date to carbonate weathering crust. The results show that the age of Xinpu profile is younger than 8.5 Ma, and the age of Guanba profile is younger than 7.3 Ma, and the age of Daxing profile is younger than 4.6 Ma.