玛湖凹陷八道湾组辫状河三角洲沉积特征及模式

发布时间：2018-06-04 19:22

本文选题：准噶尔盆地 + 玛湖凹陷　；参考：《新疆石油地质》2017年06期

【摘要】：早侏罗世八道湾期,准噶尔盆地玛湖凹陷构造环境相对稳定,沟槽和坡折发育,物源供给充足,为辫状河三角洲发育提供了条件。辫状河三角洲沉积具有粒度粗、成熟度低、牵引流沉积构造发育、垂向上多期水下分流河道切割叠置和呈正旋回沉积序列等特征,可细分为辫状河三角洲平原和辫状河三角洲前缘2种亚相。在平面上,由于不同地区坡度不同,而导致辫状河三角洲规模具有差异,陡坡带辫状河三角洲规模较大,缓坡带辫状河三角洲规模相对较小。在垂向上,在湖平面上升的不同阶段,辫状河三角洲发育不同的亚相组合和砂体构型,湖平面上升早期,发育辫状河三角洲平原亚相;湖平面上升中期,辫状河三角洲前缘亚相占据主导地位;湖平面上升晚期,发育"泥包砂"型辫状河三角洲前缘沉积。
[Abstract]:In the Badaowan period of the early Jurassic, the tectonic environment of Mahu depression in Junggar Basin was relatively stable, the trench and slope break developed, and the material supply was sufficient, which provided the condition for the development of braided river delta. The braided river delta deposits are characterized by coarse granularity, low maturity, developed tractive current sedimentary structures, vertical multi-stage underwater distributary channel cutting overlay and positive cyclic sedimentary sequence, etc. It can be subdivided into two subfacies: braided river delta plain and braided river delta front. On the plane, the braided river delta scale is different because of the different slopes in different regions. The braided river delta scale of steep slope belt is larger than that of gentle slope zone braided river delta scale is relatively small. The braided river delta develops different subfacies assemblages and sandbody configurations in the vertical direction and at different stages of the lake level rising, and develops braided river delta plain subfacies in the early stage of the lake level rising, and the middle stage of the lake level rising. The braided river delta front subfacies dominated and the "mud-covered sand" type braided river delta front deposits developed in the late stage of lake level uplift.
【作者单位】：中国石油杭州地质研究院;中国石油新疆油田分公司勘探开发研究院;
【基金】：国家科技重大专项(2016ZX05001-05)
【分类号】：P618.13

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