本文關(guān)鍵詞：松遼盆地長(zhǎng)嶺斷陷龍鳳山次凹下白堊統(tǒng)營(yíng)城組物源與沉積相研究　出處：《天然氣地球科學(xué)》2017年01期 　論文類型：期刊論文

  更多相關(guān)文章： 物源 重力流 沉積相 營(yíng)城組 龍鳳山次凹

【摘要】：根據(jù)巖心、測(cè)井、地震、錄井和薄片等資料,明確龍鳳山次凹營(yíng)城組的物源方向和沉積相類型,結(jié)合古地貌格局、同沉積斷裂活動(dòng)和古氣候特征,對(duì)研究區(qū)沉積相時(shí)空演化進(jìn)行了研究。研究結(jié)果表明,龍鳳山次凹營(yíng)城組沉積時(shí)期發(fā)育3個(gè)物源區(qū),分別為西南部的變質(zhì)巖物源區(qū)、南部的中基性巖漿巖物源區(qū)和東南部的巖漿巖物源區(qū)。研究區(qū)營(yíng)城組沉積相類型以扇三角洲相和近岸水下扇相為主。扇三角洲相發(fā)育于湖盆洪水面和風(fēng)暴浪基面之間的濱淺湖環(huán)境中,沿扇體展布方向從碎屑流、濁流沉積轉(zhuǎn)化為牽引流沉積;近岸水下扇相發(fā)育于風(fēng)暴浪基面之下的半深湖—深湖環(huán)境中,沿扇體展布方向從滑動(dòng)滑塌逐漸轉(zhuǎn)變?yōu)樗樾剂骱蜐崃鞒练e。研究區(qū)古地貌南高北低,坡度自西向東逐漸變陡,來(lái)自東南物源區(qū)的碎屑物質(zhì)沿陡坡滑動(dòng)滑塌快速入湖,形成近岸水下扇相;受同沉積斷裂活動(dòng)的影響,斷裂兩盤高差增大,在古地貌上形成向湖盆深處延伸的斷槽,來(lái)自西南和南部物源區(qū)的碎屑物質(zhì)受洪水搬運(yùn)并沿?cái)嗖凵畎继幎逊e,形成扇三角洲相;受古氣候逐漸溫?zé)岢睗竦挠绊?季節(jié)性洪水頻發(fā),導(dǎo)致研究區(qū)西南斷槽帶和南部斷槽帶發(fā)育進(jìn)積為主的扇三角洲相砂礫巖體,東南陡坡帶營(yíng)Ⅴ砂組沉積時(shí)期開始發(fā)育進(jìn)積為主的近岸水下扇相砂礫巖體,不同沉積相類型的砂礫巖體連片分布,緊鄰東北洼陷帶的半深湖—深湖相泥巖,形成研究區(qū)良好的源儲(chǔ)對(duì)接關(guān)系。
[Abstract]:According to the core, logging, seismic, logging and thin slice data, the source direction and sedimentary facies types of the Longfeng Mountain Suwa Yingcheng formation are determined, and the sedimentary fault activity and paleoclimate characteristics are combined with the paleogeomorphic pattern. The spatiotemporal evolution of sedimentary facies in the study area has been studied. The results show that three provenances of metamorphic rocks originated from the southwestern metamorphic rocks were developed in the Sedimentary period of the Subsaw Yingcheng formation in Longfeng Mountain. The sedimentary facies of Yingcheng formation are mainly fan delta facies and nearshore underwater fan facies. Fan delta facies are developed on the flood surface of lake basin and storm wave base. Between the shallow lake environment. Along the distribution direction of fan body from clastic flow to turbidite deposition into traction flow deposition; The near-shore underwater fan facies developed in the semi-deep lacustry-deep lacustrine environment below the storm wave surface, and gradually changed from sliding collapse to clastic flow and turbidite deposition along the spreading direction of the fan body. The paleogeomorphology in the study area is high and low in the north and south. The slope gradually steeped from west to east, and the debris from the southeastern provenance slid into the lake along the steep slope, forming the near-shore underwater fan facies. Influenced by the synsedimentary fault activity, the height difference between the two plates of the fault increases, forming a fault trough extending to the deep part of the lake basin on the paleogeomorphology, and the debris material from the source area of the southwest and the south is transported by the flood and accumulates along the deep concave of the fault trough. Forming fan delta facies; Due to the influence of paleoclimate, seasonal floods occur frequently, which leads to the development of alluvial fan delta sandstones in the southwestern and southern fault troughs of the study area. During the depositional period of Ying鈪，

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