Various millimetre-, centimetre- and metre-scale soft-sediment deformation structures (SSDS) have been identified in the Upper Ordovician and Lower-Middle Silurian from deep drilling cores in the Tarim Basin (NW China). These structures include liquefied-sand veins, liquefaction-induced breccias, boudinage-like structures, load and diapir- or flame-like structures, dish and mixed-layer structures, hydroplastic convolutions and seismic unconformities. The deformed layers are intercalated by undeformed layers of varying thicknesses that are petrologically and sedimentologically similar to the deformed layers. The SSDS developed in a shelf environment during the early Late Ordovician and formed initially under shear tensile stress conditions, as indicated by boudinage-like structures; during the latest Ordovician, SSDS formed under a com-pressional regime. The SSDS in the Lower-Middle Silurian consist mainly of mixed layers and sand veins; they formed in shoreline and tidal-flat settings with liquefaction features indicating an origin under a compressional stress regime. By Silurian times, the centre of tectonic activity had shifted to the south-eastern part of the basin. The SSDS occur at different depths in wells that are close to the syn-sedimentary Tazhong 1 Fault (TZ1F) and associated reversed-thrust secondary faults. Based on their characteristics, the inferred formation mechanism and the spatial association with faults, the SSDS are interpreted as seismites. The Tazhong 1 fault was a seismogenic fault during the later Ordovician, whereas the reversed-direction secondary faults became active in the Early-Middle Silurian. Multiple palaeo-earthquake records reflect pulses and cyclicity, which supports secondary tectonic activity within the main tectonic movement. The range of SSDS structures reflects different developments of tectonic activity with time for the various tectonic units of the centralbasin. The effects of the strong palaeo-earthquake activity coincide with uplift, fault activity and syn-tectonic sedimentation in the study area during the Late Ordovician to Middle Silurian.

: The early Jurassic soft‐sediment deformation occurring within lacustrine sandstone is distributed mainly in the Wuqia region of SW Tianshan Mountains, Xinjiang, western China. Triggered by earthquakes, such deformation was found to occur in three beds overlying the lower Jurassic Kangsu Formation. The main styles of deformation structures comprise load cast, ball‐and‐pillow, droplet, cusps, homogeneous layer, and liquefied unconformity. The deformation layers reflect a series of three strong earthquakes at the end of early Jurassic in the Wuqia region. The differences of deformation mechanisms undergone might represent the varying magnitudes of the earthquake events. During the early Jurassic, the Wuqia region was located in a pull‐apart basin controlled by the significant Talas–Ferghana strike‐slip fault in central Asia, which initiated the soft‐sediment deformation induced by earthquakes. Our research suggests that the paleoseismic magnitudes could have ranged from Ms 6.5 to 7.

The Wanbaogou Group-complex is a suit of mélange aggregation of the Eastern Kunlun orogenic belt, which is divided into two parts, i.e. the exotic blocks and the matrix strata. Based on stromatolite fossils yielded in the exotic blocks, the age of this group-complex was once defined to the Precambrian. Recently, two Paleogene palynological assemblages have been found in samples from the matrix strata of the Upper Part in this group-complex by the authors: in ascending order, the Alnipollenites-Quercoidites assemblage of Late Eocene and the Caryapollenites-Pinuspollenites assemblage of Early Oligocene. Those results show that the matrix strata of this mélange were mainly formed in Paleogene, and the event causing mixture should be a Himalayan Movement Phase. This paper is designed to provide some detailed evidence for determining the age of the matrix strata in this group-complex based upon study at the Kunlunqiao Section, which would be of important geological significance for further understanding this group-complex as a suit of mélange aggregation and establishing or improving the stratigraphic framework of the studied region. The new finding will certainly benefit from now on the investigation on geotectonic and sedimentary evolution of Eastern Kunlun.

The western part of the Tarim Basin in Xinjiang is one of the main areas in China where the marine Cretaceous is well developed. The Upper Cretaceous Yingjisha Group represented mainly by sediments of littoral, near-shore neritic and estuarine facies is divided in ascending order into the Kukebai Formation, the Oytak Formation, the Ygezya Formation and the Tuylouk Formation. 14 Vol.

Continentsontinent collision is the most important driving mechanism for the occurrence of various geological processes in the continental lithosphere. How to recognize and determine continent-continent collision. especially its fourdimensional temporal-spatial evolution, is a subject that geological communities have long been concerned about and studied, Continent-continent collision is mainly manifested by strong underthrusting (subduction) of the underlying block along an intracontinental subduction zone and continuous obduction (thrusting propagation) of the overlying block along the intracontinental subduction zone, the occurrence of a basin-range tectonic framework in a direction perpendicular to the subduction zone and the flexure and disruption of the Moho. On the basis of numerical modeling, the authors discuss in detail the couplings between various amounts and rates of displacement caused by basin subsidence, mountain uplift and Moho updoming and downflexure during obduction (thrusting propagation) and subduction and the migration pattern of basin centers. They are probably indications or criteria for judgment or determination of continent-continent collision. 2 Calculated Initial Model and RemeshingRemeshing is based on the conventional crustal structure model (Wu et al., 1989;Ding, 1991; Yuan, 1996;Wang et al., 1997;Teng et al., 1999). the 35 km thick crust above the Moho is divided into the upper, middle and lower layers, namely, an 8 km thick sedimentary cover (the upper layer of the upper crust), a 12 km thick granitic layer (the lower layer of the upper crust) and a 15 km thick basaltic layer (the lower crust). The number of the initial elements of the remeshing is 12 and the number of the nodes is 20. On calculation, the actual number of the elements is 468 and the total number of the nodes is 520. , 2002. GPS velocity field and active crustal deformation in and around the Qinghai-%bet Plateau. Earth Science Frontiers, 9(2): 442450 (in Chinese with English abstract). 69-80.