The SSZ Ophiolite Late Paieozoic in the Central Part of Jilin Province

This paper conducted petrological and geochemical studies on rock samples obtained from 5 1: 50 000 regional geological survey 22 newly collected rock samples, including 20 items from the new geological of Jilin Province (2017) and others 21 items were completed by peers and 63 rock samples were analyzed for petrology and geochemistry study; U-Pb isotope geochronology study of new made 5 pieces of rock and millstone construction of 8 layers of 70 zircons. Obtain accurate information on the geological age, constituent rock units, geological structural environment, and the time limit of the collision and closure between the Siberian Plate and the North China Plate of serpentinite (suite) , providing empirical evidence of spatiotemporal geological records for understanding the transformation of serpentinite, Central Asian orogenic belt (Jilin section) , and ancient Asian oceanic tectonic domain to the coastal Pacific tectonic domain in the region. The results confirm that the Toudaogou Celery Gully and Xiaosuihe Magnesium Iron Super Magnesium Iron rock blocks in the area, which are temporally and spatially related, constitute the "SSZ type ophiolite in central Jilin Province". The rock units that make up it (from top to bottom) are: marine carbonate rock siliceous rock overlying rock series; spirille hornblende basaltic andesite (boehmite or high magnesium andesite) volcanic rock unit, belonging to E-MORB or P-MORB, formed in a pre arc environment, with a peak age of 300 Ma-265 Ma; cumulate and vein rock units (olivine pyroxene rock, gabbro and diabase) , with an age of 297 Ma-265 Ma. The metamorphic pyroxene peridotite and metamorphic peridotite rock units originate from weakly depleted to weakly metasomatized enriched mantle, with ages ranging from 317 Ma to 270 Ma. The temporal and spatial coordination of each rock unit indicates a typical SSZ type serpentinite, dating back to the Late Paleozoic era. Its unique spatiotemporal characteristics confirm that plate collision and subduction began in the Carboniferous period, with a peak period of 317 Ma-265 Ma; The closure period of the ancient Asian Ocean (250 Ma-243 Ma) ; The cover layer consists of plump conglomerate and Jiangjia conglomerate (250 Ma-243 Ma) .