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Yuelong Chen, China University of Geosciences (Beijing) (China)
Hongfei Zhang, China University of Geosciences (Wuhan) (China)
Dapeng Li, China University of Geosciences (Beijing) (China)
Jian Zhou, China University of Geosciences (Beijing) (China)
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The western Qinling Shan is the western extension of the Eastern Qinling Shan connecting the North China craton, the Qilian and Qaidam, and the Songpan-Ganzi block from north, west, and south, respectively. Clastic sedimentary rocks from this region, of Precambrian to Triassic age, are studied in this paper. Detrital zircons were extracted from the sedimentary rocks for U-Pb dating through LA-ICPMS. Nd depleted mantle model ages resemble those of the Yangtze craton, with a statistical population of 1.55Ga-1.98Ga, peaking around 1.81Ga, in contrast to Paleoproterozoic and Archean population of the North China craton.
Devonian detrital zircon U-Pb ages of 930 to 730Ma indicate their affinity to the Yangtze craton, which was the intensive crustal growth stage in the provenance region (during Late Paleozoic). The majority of the Permo-Triassic clastic sedimentary rocks are characterized ages older than 1600Ma. Detrital zircon U-Pb ages and Sm-Nd isotopic compositions indicate that the basement rocks, on the southern margin of the North China craton, became an important component of the Permo-Triassic clastic sedimentary rocks. The Yangtze craton conjoined the North China craton during Triassic time. Up to 50% of the Permo-Triassic clastic sedimentary rocks of the west Qinling segment contain material from the basement rocks on the southern margin of North China craton.
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