本文選題：細(xì)粒沉積　切入點：有機(jī)質(zhì)類型　出處：《地質(zhì)學(xué)報》2017年05期 　論文類型：期刊論文

【摘要】：鄂爾多斯盆地西南地區(qū)廣泛發(fā)育細(xì)粒沉積物。在大量鉆井、測井資料的基礎(chǔ)上,通過巖芯分析、地球化學(xué)測試等方法,從湖泊演化過程中水體鹽度、氧化還原條件、生產(chǎn)力變化及地化特征等方面研究細(xì)粒沉積物特征與分布規(guī)律,進(jìn)而分析細(xì)粒沉積物主控因素。結(jié)果表明:鄂爾多斯盆地西南地區(qū)延長組長7沉積期,氣候溫暖潮濕,半深湖—深湖大面積分布,富有機(jī)質(zhì)細(xì)粒沉積物發(fā)育。該期形成的富有機(jī)質(zhì)頁巖主要受湖盆底形、砂體沉積模式的影響。尤其在長73沉積期,快速湖侵,湖水深度和范圍急劇增加,古生產(chǎn)力高,湖泊表層水體與底層水體存在鹽度分層,形成大面積缺氧環(huán)境,有利于富有機(jī)質(zhì)頁巖大規(guī)模發(fā)育與保存,在深湖區(qū)平緩地帶,陸源碎屑供給不足,有機(jī)碳含量高,有機(jī)質(zhì)類型好,以Ⅰ、Ⅱ型為主,斜坡帶半深湖區(qū),陸源碎屑影響明顯,粉砂質(zhì)泥巖發(fā)育,干酪根以Ⅱ型為主,局部地區(qū)發(fā)育Ⅲ型干酪根。
[Abstract]:Fine grain sediments are widely developed in the southwest of Ordos Basin. On the basis of a large amount of drilling and logging data, through core analysis and geochemical testing, the salinity and redox conditions of the water body during the evolution of the lake are studied. The characteristics and distribution of fine-grained sediments are studied in terms of productivity changes and geochemistry characteristics, and the main controlling factors of fine-grained sediments are analyzed. The results show that Yanchang Group 7 sedimentary period, warm and humid climate in southwest Ordos Basin, and so on. The organic matter rich shale formed in this period was mainly influenced by the lacustrine basin bottom and the sedimentary model of sand body, especially during the Chang73 sedimentary period, the rapid lacustrine transgression. The depth and range of lake water increased sharply, the paleoproductivity was high, the surface water and bottom water of the lake were stratified by salinity and formed a large area of anoxic environment, which was conducive to the large-scale development and preservation of organic matter rich shale, and in the gentle zone of deep lake region. The continental clastic supply is insufficient, the organic carbon content is high, the organic matter type is good, mainly type 鈪，

本文編號：1637226