准噶尔盆地南缘和东缘地区上三叠统及沉积特征研究

发布时间：2018-01-05 01:16

本文关键词：准噶尔盆地南缘和东缘地区上三叠统及沉积特征研究　出处：《中国地质大学(北京)》2015年硕士论文　论文类型：学位论文

【摘要】：准噶尔盆地南缘和东缘地区上三叠统岩石地层称为小泉沟群,由下向上分为黄山街组和郝家沟组。通过对研究区露头剖面的实测,详细观察了上三叠统的岩石类型、沉积构造及其组合特征,详细分析了沉积相、亚相和微相,总结出准噶尔盆地南缘和东缘晚三叠世的沉积环境特征。准噶尔盆地南缘和东缘地区上三叠统剖面出露较好,沉积标志丰富,沉积相标志明显,其沉积环境均为陆相。沉积相类型主要为三角洲相、河流相和湖泊相。研究区发育的河流沉积主要为辫状河沉积和曲流河沉积,入湖泊所形成的三角洲以辫状河三角洲和曲流河三角洲为主。其中,准噶尔南缘地区的沉积相主要为曲流河和曲流河三角洲,东缘地区的沉积相主要为辫状河和辫状河三角洲。通过对准噶尔南缘-东缘上三叠统地层发育、沉积特征、层序地层的研究,可以重塑晚三叠世准噶尔盆地东部的沉积古地理格局和晚三叠世准噶尔盆地南侧的博格达山脉的隆升速度较低,山前地形变缓,形成了准噶尔盆地南缘黄山街组和郝家沟组曲流河三角洲的沉积;而此时北部的克拉美丽山继续快速隆升,形成了郝家沟组底部的不整合和辫状河流相的“玛瑙砾岩”沉积。因此,晚三叠世准噶尔盆地东部湖盆两侧的的地势为南缓北陡。
[Abstract]:The Upper Triassic lithostratigraphy in the southern and eastern margin of Junggar Basin is called the Koizumi Group, which is divided into Huangshanjie formation and Haojiagou formation from the bottom up. The outcrop profile of the study area is measured. The rock types, sedimentary structures and their assemblages of the Upper Triassic are observed in detail. The sedimentary facies, subfacies and microfacies are analyzed in detail. The sedimentary environment characteristics of the late Triassic in the southern margin and eastern margin of Junggar basin are summarized. The upper Triassic section of the southern margin and eastern margin of Junggar basin is better exposed with abundant sedimentary markers and obvious sedimentary facies marks. The sedimentary environment is continental facies. The sedimentary facies are mainly delta facies, fluvial facies and lacustrine facies. The fluvial deposits developed in the study area are mainly braided river deposits and meandering river deposits. The delta formed by the lake is mainly braided river delta and meandering river delta, among which, the sedimentary facies in the southern margin of Junggar are mainly meandering river and meandering river delta. The sedimentary facies in the eastern margin are mainly braided river and braided river delta. The stratigraphic development, sedimentary characteristics and sequence stratigraphy of Upper Triassic in the southern margin of Junggar and the eastern margin of Junggar are studied. The sedimentary paleogeography in the eastern part of the late Triassic Junggar Basin and the uplift rate of the Bogda Mountains on the southern side of the late Triassic Junggar Basin can be remolded. The deposits of Huangshanjie formation and Haojiagou Suite River Delta were formed in the southern margin of Junggar Basin. At this time, the Karamie Mountain in the north continued to uplift rapidly, forming the unconformity at the bottom of the Haojiagou formation and the "agate conglomerate" deposit in the braided fluvial facies. The topography of the eastern lake basin of the late Triassic Junggar Basin is steep in the south and north.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13;P534.51

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