Geochronological And Geochemical Characteristics Of The Lincang Complex Granite And Its Geological Significance,Yunnan Province

The Lincang granite is the largest complex batholith in the western Yunnan Province,which is crucial for understanding the tectonic processes and constraining on the closure of the Changning-Menglian Paleo-Tethys.Baseed on petrology,geochemistry,and isotopic U-Pb chronology,magmatic resource and tectonic setting have been discussed.Major results and understanding as follows:(1)The Permian granitic rocks have been recognized by research field.LA-ICP-MS U-Pb geochronology of the Lincang show that hornblende granodiorite has age of late Middle Permian(260.7 ± 1.2Ma),biotite monzogranite has age of early Early Triassic(251.9 ± 1.2Ma).(2)Mineralogical and geochemical characteristics indicate that the Middle Permian to Early Triassic rocks are mainly I-type granite,and the Late Triassic rock arre mainly S-type granite.(3)The Changning-Menglain Paleo-Tethys experienced a complex evolutionary history involving subduction of the oceanic plate from Early to Late-Permian,terrane-continent collision during late Permian to early Triassic,and post-collision evolution from the middle-to late-Triassic...