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内蒙古科右中旗—突泉地区出露一套缺少化石、遭受接触变质作用的巨厚层碎屑岩,其先后被划归为早二叠世索伦组、晚二叠世林西组、下寒武统。取自该套地层砂岩样品的碎屑锆石LA-ICP-MS U-Pb定年数据表现为2个主要年龄区间:255~354Ma,峰值年龄为263Ma和283Ma;413~529Ma,峰值年龄为485Ma。另有5颗锆石的年龄值分别为625Ma、965Ma、1372Ma、1707Ma、1727Ma。263Ma的峰值年龄限定了该套地层的沉积下限应为晚二叠世,结合区域地层对比,认为是晚二叠世林西组。该地层年代为突泉盆地下伏第二低阻层为林西组的推断提供了年代学证据。
Inner Mongolia Kezuozhongqi - Tuquan area exposed a lack of fossils, contact metamorphism giant thick clastic rocks, which has been classified as the Early Permian Solon Formation, Late Permian Linxi Formation, Lower Cambrian. LA-ICP-MS dating of detrital zircon from this suite of sandstone samples showed two major age intervals of 255-354 Ma with peak ages of 263 Ma and 283 Ma, 413-529 Ma and a peak age of 485 Ma. Another five zircons age values were 625Ma, 965Ma, 1372Ma, 1707Ma, 1727Ma. The peak age of 263Ma defines that the sedimentary lower limit of this set of strata should be Late Permian, which is considered to be Late Permian Linxi Formation in combination with regional stratigraphic correlation. The age of the strata provided the chronological evidence for the inferred that the second low-resistivity layer underlying the Tuquan Basin belongs to the Linxi Formation.