Poster #T228 REDUCED ANTERIOR CINGULATE GRAY MATTER VOLUME AND THICKNESS IN SUBJECTS WITH DEFICIT SCHIZOPHRENIA

Abstract

The Uchkoshkon tin deposit is one of the largest deposits in the Sn–W Saryjaz ore district of Eastern Kyrgyzstan. The district coincides spatially with the Saryjaz syntaxis, which is the narrowest portion of the South Tien Shan collisional belt. The syntaxis is distinguished by collisional thrust tectonics and postcollisional A-type granite magmatism of Permian age. The Uchkoshkon deposit is in the exocontact zone of a 260-km2, 273–279 Ma, ilmenite series, high heat production, biotite granite pluton. A satellite granite stock (400 × 250 m) and an explosive breccia pipe (450 × 150 m), crosscutting the stock, are the central structural features of the deposit area. The main stock, accompanied by Li–F felsite dykes, controlled early-stage Mo–W and Sn–W greisen–stockwork mineralization that surrounds the apical portion of the stock. The breccia pipe postdates the emplacement of the Li–F felsite dykes and greisen–stockwork mineralization. The pipe is rooted in main pluton and has been traced by a borehole to a depth of 800 m. The breccia was injected by a swarm of tree-like branching dykes with diffuse contours consisting of K- and B-rich rhyolite porphyry cementing the breccia fragments. The main breccia body has been intruded by a much smaller (150 × 100 m) hydrothermal breccia pipe with quartz–tourmaline matrix, which immediately preceded main-stage lode mineralization. The majority of the lodes occur outside the breccia pipe within a zone of pervasive scapolitization that surrounds the main pluton. The main-stage lodes are represented by quartz–tourmaline–cassiterite veins with minor sulfides, which occupy a series of steeply-dipping, near-parallel, north–northeast-trending shear fractures that are related to postcollisional strike-slip tectonics. Where quartz–tourmaline–cassiterite veins crosscut moderately-dipping skarn deposits, the latter are commercially mineralized with cassiterite, nordenskioldine and borosilicate minerals. The formation of both explosive breccia and main-stage lode mineralization was related to the evolution of B- and H2O-rich residual magma deep within the main pluton. The suggested formation model of the Uchkoshkon tin deposit is generally applicable to other major Sn- and Sn–W deposits in the Saryjaz ore district.