Zircon SHRIMP U-Pb Dataing of the Gneiss Granite on the Southwestern Margin of the Tarim Basin

Discovered several gneiss tonalite bodies on the southwestern margin of the Tarim basin have been reported in the paper.They are possessed of higher Si,Al,Na; enriched in LREE,LILE and Zr,Hf,Ti of HFSE,depleted HREE and P,Ni,Cr of HFSE,and possessed of A-type granite features in geochemistry.Zircon SHRIM PU-Pb dataing showed that there are three group age: the first group age is (1970±47) Ma (n=4,MSWD=2.4) which recorded succeeding zircon age of magma seizured; the second group age is (764±33) Ma (n=4,MSWD=2.50) which represented intruding age of gneiss granite; the third group age is (424±16) Ma (n=6,MSWD=1.03) which implied age of Caledonnian tectonic event.It may be provided a record of magma function brokenup Paleo-continent of Neo-Proterozoic in the Tarim Basin,it provides an important basis for the stratigraphic division in this district and an important information of the geological tectonic evolution.