鄂尔多斯盆地周缘延长组露头剖面发育，地层出露齐全，是研究陆相湖盆沉积特征和生油特征的 有利地区。该文对周缘延长组露头剖面作了系统采样和测定，显微镜下观察了砂岩碎屑组分，并采用计点 法对组分进行了统计。根据碎屑组分与重矿物组合特征，结合盆地内部钻井剖面碎屑组分特征，对延长组 物源进行了探讨。研究认为：鄂尔多斯盆地晚三叠世延长组沉积期存在东北、东南、西南、西部、西北及北 部等多个不同方向的物源，其中东北、西部和西北物源控制的沉积体系延伸远、分布范围广；不同物源控 制沉积体系及同一沉积体系不同沉积期砂岩的碎屑组分、重矿物组合及填隙物成分和组合存在较大差 异。综合研究表明，盆地周缘延长组露头剖面砂岩组分特征研究对盆地物源分析和沉积体系划分、砂体展 布、有利储层预测、钻井剖面地层对比及井位部署和储层改造均具有重要意义。

Outcrops of Yanchang Formation in the margin of Ordos Basin are widely spread with abundant strata. It is favorable area for research of sedimentary and hydrocarbon generation characteristics in lacustrine basin. According to systematic sampling and measurement of the outcrops of Yanchang Formation, combining with sandstone detrital component analysis, this paper discussed the provenance of Yanchang Formation. It is considered that there exist several provenances from different orientation in Late Triassic in Ordos Basin, including east-north, eastsouth, west-south, west, west-north and north, and sedimentary systems which dominated by the east-north, west and west-north proveniences spread widely. There are great differences of detrital components, heavy mineral assemblages, and interstitial material components and assemblages of sandstones under different sedimentary systems that dominated by different provenances or different depositional stages in the same sedimentary system. Comprehensive studies indicate that the research of sandstone component characteristics of outcrops has great significance for provenience analysis, sedimentary systems division, sand body distribution and favorable reservoir prediction, stratigraphic correlation between outcrops and cores, exploratory well deployment and reservoir reconstruction.