The Analysis of Detrital Heavy Minerals in CretaceousTertiary Sandstones, Kuqa Depression and Their Implications for Provenance 

Key words: 
• heavy mineral /
• Kuqa depression /
• southern Tianshan /
• provenance /
• electronic microprobe /
• garnet /
• ilmenite

Abstract: Detrital sedimentation is the direct record in basin for mountain uplift and erosion. The analysis of detrital minerals, including heavy minerals, is a key means for basinmountain coupling studies. The distribution characteristics of heavy minerals in CretaceousTertiary sandstones, Kuqa depression have been studied systemically in this paper, and chemical compositions of detrital garnets and ilmenites have been analyzed by electronic microprobe. The results illustrate that the provenance area of CretaceousTertiary〖KG*2〗sandstones, Kuqa depression, are mainly composed of sedimentary rocks, metamorphic rocks and little intermediatefelsic igneous rocks.〖KG*2〗The〖KG*2〗garnets in Cretaceous sandstones come from blueschist that〖KG*2〗located in the southwest〖KG*2〗Tianshan and lowgrade metamorphic rocks by lager proportionally. The garnets in Tertiary sandstones enrich almandine, which come from highgrade metamorphic rocks. The provenance of most ilmenites in Cretaceous sandstones is metamorphic rocks, and the proportion of igneous rocks provenance increase in Tertiary. These analysis show that southern Tianshan uplift and erosion extensively from Tertiary, as a result of which the provenance of blue schist〖KG*2〗in Paleozoic accretion from north margin of south〖KG*2〗Tianshan has been curtained. With〖KG*2〗deeply erosion of Tianshan, more and more highgrade metamorphic and igneous rocks are exposed.