【作者】 杨为先；

【导师】 李勇；

【作者基本信息】 长安大学 ， 构造地质学， 2008， 硕士

【摘要】 陕西省西乡县下高川地区有着独特的地层发育序列,在寒武系之上,缺失奥陶系、志留系和早中泥盆世的地层,发育有晚泥盆世到早三叠世的地层,和周边的地层单元分区对比鲜明。该地区地层变形明显,褶皱和断层发育。前人在该地区已作过大量研究,但从未有1:5万的大比例尺的地质调查工作。本文作者在参加裴先治教授陕南1:5万矿调项目过程中,通过野外地质填图的方法对这一地区的地质情况进行详细的观察,认清了下高川地区的地质情况,主要从岩石地层学入手,通过岩石地层的划分与对比,沉积相和沉积环境的判定,岩层之间的接触关系,以及地层单元的构造形态,从而恢复和重建该地区的地质演化历史,取得了如下几点认识:1、通过野外1:5万地质填图的实际观测,结合前人资料,对泥盆系-石炭系地层进行了进一步的划分和确认。从下至上划分出六套岩石地层单位:上泥盆统铁矿梁组、蟠龙山组、下石炭统茶叶坡组、展坡组、上石炭统大埔组、马平组。2、泥盆纪-石炭纪期间,高川盆地为一水深较浅的海槽,经历了从最初的滨海海滩相沉积转变为缓坡型碳酸盐台地再到石炭纪镶边碳酸盐陆棚体系的演化过程;而周围地层却上升为陆地出现地层缺失。3、扬子地块与南秦岭在泥盆纪受古特提斯伸展构造作用影响而分裂,扬子地块北缘局部地区发生裂陷形成海槽。而且在晚泥盆世-石炭纪期间海水较浅,但范围不断扩大。4、下高川地区二叠纪的确存在过深水海盆,是勉略洋的东延部分。下高川地区以及整个勉略带二叠纪的剧烈拉张裂陷,与峨眉山大陆溢流玄武岩喷发互为响应,说明了区域的拉张构造背景,这是中国对古特提斯二叠纪扩张的响应。5、在三叠纪时,包括下高川地区在内的整个镇巴地区发育大致相同的地层沉积序列,说明从三叠纪开始,下高川地区和扬子地台北缘其他地区有着相同的沉积环境。更多还原

【Abstract】 Uique stratum sequence spread out Xiagaochuan area in Xixiang county, Shanxi province, that loss Ordovician, Silurian, low- and middle-Devonian, have the stratum from Late Devonian to Early Triassic, this is different from around the stratum. Obviously deformation, the folds and faults taken place in the region. Ancestors did most researching work , but never have 1∶50000 region geological survey in the area. The author take part in the 1∶50000 region geological survey project that preside over by professor Pei Xianzhi, through the yield geological mapping, grasping the detailed geological circumstances, recognizing the geological settings in Chuhe area, mainly start from lithostratic units, through division and contrast of lithostratic units, and determine the sedimentary facies and the environment, the contacts between rock units, as well as the formation of the units constructed forms, so as to rehabilitation and reconstruction of the region’s geological evolution history. Made the following points awareness:1. Basid on materials of the predecessor and the 1∶50000 investigate achievement, farther divided and confirmed the stratum in Devonian to Carboniferous. From the bottom of a rock formation divided into six units: Tiekuangliang Formation and Panlongshan Formation of the top Devonian, Chayipo Formation and Zhanpo Formation of the low Carboniferous, and Dapu Formation and Maping Formation of the top Carboniferous.2. The shallow trough at Gaochuan basin in Devonian to Carboniferous, experienced a coastal beaches from the initial deposit into a gentle slope of the Carboniferous carbonate platform and then to flanger carbonate shelf system evolution, and it will rise to the formation around a land formation missing.3. Yangtze block and Qinling Mountains extended by the ancient Tethys tectonic effects of separation in Devonian, and Yangtze block in some areas in the northern margin rift formed trough, And shallow water during the Late Devonian to Carboniferous, but the scope has expanded.4. The deep basin exist in the Xiagaochuan aera in Permian, it is Mianlue Ocean extension of the east. The Xiagaochuan aera as a whole Mianlue belt strongly rift in Permian, and Emeishan continental flood basalt eruption response to each other, indicates that the extension of the regional tectonic setting, which is response to the China’s ancient Tethys expansion in Permian. 5. In the Triassic, including Xiagaochuan aera of the entire Zhenba region, roughly the same stratum sedimentary sequence, indacates that, Xiagaochuan aera , the Yangtze Block and the north of it have the same sedimentary environment from the Triassic更多还原