Sedimentary Provenance Analysis Of Chang8 In Huanxian Area Of Ordos Basin

Provenance Analysis is an important part of the study of basins and Orogeny., which can help determine the sedimentary provenance, the depositional systems, sediment transport path and the tectonic setting. There are several methods about provenance analysis, the main methods contain heavy mineral law, clastic rocks law, fission track method, deposition method, geochemistry, isotope, and quartz C. The application of these methods has conditions and limitations. Present the isotope and geochemical methods have broad prospects.Ordos Basin is a large inland depression late Triassic basin which has several high erosions around the Antiquities source. Ancient metamorphic rocks constitute the margins of the ancient land. The western Ordos Basin today stands LiuPan Mountains, also there has nearly north-south distribution of Precambrian continental blocks, Therefore many scholars believe that there has ancient western Ordos Basin uplift. Late Triassic the western sedimentary border is consistent with current boundary of the basin. But recent research suggests that the western lift does not exist. Western uplift margin occurred between the period of Yanshan and Himalayan.After comprehensive analysis of the heavy mineral compositions, detrital compositions, geochemical elements (major elements and trace elements) and CL of quartzs, The study area was divided into four different sedimentary areas and mixed areas. The Provenance are separately Northwest Southern margin of Alxa ancient land, Western Haiyuan uplift, Southwest Liupanshan and Longxi ancient land. Also they have good match with the distribution of sand bodies. The Western Haiyuan uplift is confirmed exist as the main sedimentary provenance, the tectonic setting is Active continental margin, which is also Metamorphic arc here. Late Triassic Indo-China movement made the western Ordos Basin block thrust eastward by the push of Tethyan plate to the northeast. West of the basin strongly thrust, forming a foreland thrust belt. Thrust belt form the western ancient land beam, with the continuous development of the thrust belt lately.