内蒙古乌里雅斯太凹陷南洼槽坡折带粗砾斜坡扇沉积特征

斜坡扇沉积属重力流事件沉积，在我国陆相断陷湖盆中也有发育，是一种重要的相类型.针对乌里雅斯太凹陷南洼槽东部坡折带发育一套厚度大、粒级粗和相变快的砾岩体，通过精细的岩心观察，结合测井、3D地震，以及岩石分析资料等，认为该砾岩体应属于低位体系域重力流成因机制的斜坡扇沉积，并论述了研究区内的斜坡扇相带的划分，分析了其平面的相分布特征，建立了该研究区沉积相模式，为研究区岩性油气藏的进一步勘探开发提供了依据.

SEDIMENTARY CHARACTERISTICS OF THE SLOPE FAN IN THE SLOPE BREAK IN THE SOUTHERN SAG OF THE ULIASTAI DEPRESSION, INNER MONGOLIA

Slope fan sediment is of a kind of the gravity flows. It is also developed in continental fault basins. Some conglomerate bodies with heavy thickness, coarse grains and quickly changed facies occur in the slope break of the First Member of Tenger Formation in Uliastai Sag, Erlian Basin, Inner Mongolia. However, there is still much controversy about the exact origin of the conglomerate bodies and bewilderment about the size, spatial distribution, reservoir characteristics and formational model of oil pools. Based on the examination of cores, well logs, 3D seismic and petrographic data, it is concluded that the conglomerate bodies belong to slope fan formed by sediment gravity flow in the low-stand systems. With classifi cation of the slope fan in the studied area, the planar distribution of the slope fan deposits is analyzed. A sedimentary facies model of the studied area is set up. This research will be helpful to further exploration in lithologic oil pools in the area.