摘要：

通过岩石岩屑组分分析、重矿物组分分析、倾角测井、地层厚度分析等方法，对准噶尔盆地西北缘车排子地区侏罗系进行物源及古水流方向分析。岩屑组分分析指示着大致的物源前进方向，重矿物分析明确了物源泄入的主要通道，倾角测井在单井点处对古流向有相当高的表现精度，但这三种方法均存在数据平面覆盖率较低和分布密度差异大的缺陷，而运用地震层位解释所得的地层等厚度图则可以在较大尺度上的二维平面内推测沉积时期的古地形，进而可以推测古流向，但它仅是一种间接预测方法，存在局部古流向预测精度较低的不足。文中综合各种方法，将直接预测方法的高精度和间接方法的高覆盖能力结合起来，对古流向作出较高精度的预测。在古流向研究的基础上建立了冲积扇－辫状河－河泛平原沉积体系的沉积相模式。该模式认为对于水流能量保持能力差的冲积扇，其古流向应该沿短轴陡坡降方向，即大致为SEE方向，而对于水流能量保持能力较强的辫状河来说，其古流向应该沿长轴缓坡降方向，即为SE甚至SSE方向。该模式的提出对于提高地震相－沉积相的转相精度具有一定的指导意义。

Abstract:

With several methods such as analysis of detritus component ,analysis of heavy mineral component, dip log, and thickness of strata, the paper analyzes sedimentary source and paleocurrent direction of Jurassic, ChePaizi District, north-west edge of Junggar Basin. Analysis of detritus component indicates the overall progressing direction of sedimentary source, analysis of heavy mineral component makes the main passage of source clear, dip log data gives accurate paleocurrent direction in the place of each well with this kind of data, but each of these three methods has a disadvantage with low data covering rate and high variety of covering density in 2-demensional space. In contrast, isolate map of strata from seismic data can be used to give prediction of paleo-topography and paleocurrent direction in much large 2-demensional scale, but it is virtually an indirect predicting method with disadvantage of low accuracy in local place. Integrating the high covering faculty of indirect methods and the high local accuracy of direct methods, a much accurate prediction about paleocurrent direction is put forward in this paper, and based on which a sedimentary facies model of alluvial fan-braided river-river plain sedimentary system is constructed. The model shows that current of alluvial fan progresses in the direction of SEE along the short axle with steep slope for its current energy can keep only in short distance, by contraries, current energy of braided river has the ability of keeping in much long distance, its current progresses in the direction along the long axle with mild slope，namely SE or even SSE. The model is much beneficial to raising the accuracy of turning seismic facies to sedimentary facies.