LA-ICP-MS ZIRCON U-Pb DATING AND GEOCHEMISTRY OF WOLONGQUAN INTRUSION IN GAIZHOU, SOUTHERN LIAONING PROVINCE
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Graphical Abstract
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Abstract
The Wolongquan intrusion, distributed in Wolongquan Town, Gaizhou City of southern Liaoning Province, is lithologically composed of mainly porphyritic biotite monzogranite, with the LA-ICP-MS zircon U-Pb age of 1888.4±5.3 Ma, forming in the Paleoproterozoic. The geochemical characteristics of the rock body show that the average value of Na2O/K2O is 0.70, belonging to high-K calc-alkaline series. The average Rittmann index σ of 2.18 also indicates calc-alkaline series. The A/CNK ratio is averagely 1.16, representing a peraluminous type. The average of total REE content is 299.04×10-6 with right-dipping distribution patterns, characterized by moderately negative Eu anomaly with enrichment of LREEs and depletion of HREEs, enriched LILEs and depleted HFSEs, which are the features of active continental margin calc-alkaline series, belonging to the syn-collision I-type Cordillera granite. From the above, it can be inferred that the intrusion should be related to the thickening and melting of the lower crust caused by Paleoproterozoic orogeny.
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