發(fā)布時(shí)間：2018-03-08 18:40

  本文選題：下侏羅統(tǒng)　切入點(diǎn)：川西盆地　出處：《中國(guó)地質(zhì)大學(xué)(北京)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：川西盆地位于四川盆地西部,東以龍泉山斷裂為界,西至龍門山構(gòu)造帶。中三疊世以前,川西盆地沉積了大規(guī)模的海相碳酸鹽巖地層。晚三疊世進(jìn)入陸相沉積環(huán)境,發(fā)育上三疊統(tǒng)-第四系巨厚沉積物。由于現(xiàn)今呈現(xiàn)出北東向龍門山逆沖推覆帶、川西盆地、龍泉山前陸隆起相互平行的構(gòu)造格局,故川西盆地被認(rèn)為是晚三疊世以來(lái)龍門山構(gòu)造帶控制的前陸盆地。然而,龍門山中-南段顯示灌縣-安縣斷裂切割侏羅系,而且沉積物顯示為砂泥巖相的遠(yuǎn)源性質(zhì),表明早侏羅世川西原型盆地西部邊緣并非灌縣-安縣斷層。因此,重建早侏羅世川西原型盆地對(duì)理解該時(shí)期盆-山關(guān)系有重要意義。本文利用中石化勘探開(kāi)發(fā)井位資料,并與野外露頭分析相結(jié)合,通過(guò)對(duì)川西盆地下侏羅統(tǒng)沉積相進(jìn)行分析,識(shí)別出川西盆地從北到南,沖積扇-扇三角洲-濱淺湖-半深湖相沉積模式的變化,沉積相帶呈近東西展布,龍門山僅在北段山前發(fā)育沖積扇沉積,南段濱淺湖-半深湖沉積表明龍門山南段與盆地邊界并非現(xiàn)今位置。而整個(gè)早侏羅世盆地的沉降速率及早侏羅世晚期介殼灘相的大范圍分布,表明早侏羅世盆地周緣造山帶處于比較穩(wěn)定的狀態(tài)。沉積相帶近東西的展布規(guī)律表明早侏羅世盆地主要受龍門山北段-米倉(cāng)山控制,即秦嶺南緣向西南擴(kuò)展的逆沖構(gòu)造控制。
[Abstract]:The western Sichuan basin is located in the west of Sichuan basin, bounded by Longquanshan fault in the east, and to the Longmenshan tectonic belt in the west. Before the middle Triassic, the western Sichuan basin deposited large-scale marine carbonate rocks, and the late Triassic entered the continental sedimentary environment. The very thick sediments of the Upper Triassic-Quaternary system are developed. Due to the present tectonic pattern of the NNE Longmenshan thrust nappe, the western Sichuan basin and the Longquanshan Foreland uplift are parallel to each other. Therefore, the western Sichuan basin is considered to be a Foreland basin controlled by the Longmenshan tectonic belt since the late Triassic. However, the mid-south section of Longmen Mountain shows the cut Jurassic of Guanxian-Anxian fault, and the sediment shows the distant nature of sand and mudstone facies. It shows that the western margin of the early Jurassic western Sichuan archetype basin is not Guanxian-Anxian fault. Therefore, it is important to reconstruct the early Jurassic west Sichuan archetype basin to understand the basin-mountain relationship in this period. In this paper, the exploration and development well location data of Sinopec are used. Combined with outcrop analysis in the field, the sedimentary facies of the Lower Jurassic in West Sichuan Basin are analyzed, and the sedimentary models of alluvial fan fan delta shoreside shallow lake and half deep lake are identified from north to south. The sedimentary facies belt is near east-west distribution, the Longmen Mountain only develops alluvial fan deposits in the northern part of the mountain front, The littoral and semi-deep lacustrine sediments in the southern part indicate that the boundary between the south part of Longmen Mountain and the basin is not present, while the subsidence rate of the whole early Jurassic basin is distributed in a wide range in the late Jurassic period. It indicates that the early Jurassic basin peripheral orogenic belt is in a relatively stable state, and the distribution of the sedimentary facies belt near the east and west shows that the early Jurassic basin is mainly controlled by the north segment of Longmen Mountain-Micang Mountain, that is, the thrusting structure extending southwestward from the southern margin of the Qinling Mountains.
【學(xué)位授予單位】：中國(guó)地質(zhì)大學(xué)(北京)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：P534.52
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本文編號(hào)：1585092