Structural framework and its formation of the Kalpin thrust belt, Tarim Basin, north-west China, from Landsat TM data

The geological feature of the Kalpin thrust belt, Tarim Basin, China, has been a controversial issue, because of remoteness and lack of information. In this paper, Landsat Thematic Mapper (TM) data are used to discuss the structural framework of the area and its forming mechanism; the results were confirmed in the field. The PCI EASI/PACE 6.2 PC version was chosen to process the image data. The false colour composite images elaborately chosen could discriminate clearly strata of different ages and geological structures in the area. From detailed imagery interpretation, it is found that the thrust belt could be divided clearly into three parts with different deformation features from the west to the east. The west part is characterized by thrusts and folds of various sizes. The middle part consists of imbricate thrusts, transverse tear faults and some fault-related folds. The east part is expressed by the pile-up of strata sheets separated by complex thrusts and tear faults. During the Late Tertiary, the strong compression from the Tian Shan Mountains made the Kalpin Uplift thrust southward over three different structural units, thus producing entirely different structural styles within the thrust belt.