论文部分内容阅读
运用碰撞造山带大地构造相理论,研究了西昆仑甜水海地区三叠系的沉积特征及其构造环境,晚三叠世末羌塘陆块与塔里木板块南缘的晚古生代—早中生代山弧碰撞造成的前陆褶皱冲断带的构造样式及其演化。通过对地层构造岩石组合、沉积环境及其变形强度特征的分析,得出该区三叠纪的沉积是一套典型的深水—半深水的复理石建造,形成于被动大陆边缘的沉积环境;其变形具有典型的前陆褶皱冲断带特征,并将褶皱冲断带按变形特征分为5个带。提出了甜水海前陆褶皱冲断带的构造演化模式:甜水海地区在三叠纪末前,是羌塘陆块北部被动大陆边缘,晚三叠世末,该陆块与北面的塔里木板块南缘山弧发生碰撞,造成被动大陆边缘沉积停止,进入前陆的逆冲、褶皱、抬升剥蚀和前陆盆地形成演化阶段。
Using the tectonic facies theory of collisional orogenic belt, the sedimentary characteristics and tectonic setting of Triassic in the Tianshuihai area, western Kunlun, are studied. The Late Paleozoic-Early Mesozoic mountain arc collision between the Late Qiangtang terrane and the southern margin of the Tarim plate Tectonic Styles and Evolutions of the Foreland Fold and Thrust Belt. Through the analysis of stratigraphic rock assemblage, sedimentary environment and the characteristics of its deformation intensity, it is concluded that Triassic sediments in this area are a set of typical deep water - semi - deepwater flysch constructed in the depositional environment of the passive continental margin. The deformation has the characteristics of typical foreland fold-thrust belt, and the fold-thrust belt is divided into 5 zones according to the deformation characteristics. The tectonic evolution model of the Tianshuihai foreland fold-thrust belt was proposed. Before the end of Triassic, the Tianshuihai area was the passive continental margin in the northern part of the Qiangtang block. At the end of the late Triassic, the block was connected with the north Tarim plate south The collision of the marginal mountain arcs caused the deposition of the passive continental margin to cease, thrusting into the foreland, folding, uplifting and erosion and the formation and evolution of the foreland basin.