Abstract: Fine provenance analysis and clear provenance system characteristics are of great value and significance for restoring the type and distribution characteristics of paleosedimentary system and searching for sandstone enrichment areas. Based on the data of heavy minerals, seismic attributes,sand⁃land ratio and palaeogeomorphology, this study systematically analyzed the characteristics of the ancient provenance system of Shahezi Formation in Xuxi⁃Xunan area from different perspectives and levels. The study shows that the Shahezi Formation in Xuxi⁃Xunan area mainly develops two provenance systems, east and west. The provenance of the Xuxi fault terrace zone in the west is the main provenance direction of the study area, with greater provenance intensity and wider influence. The eastern provenance has a small influence range, mainly concentrated near the north and south ends, and is the secondary provenance direction. Generally speaking, the provenance direction of the study area has the characteristics of pointing from the east and west to the middle. The Shahezi formation in the study area mainly develops fan delta, Braided river delta and lake sedimentary system. The fan delta deposits are mainly controlled by the provenance of the Xuxi fault terrace belt in the west and distributed evenly along the fault terrace belt. The braided river delta deposits are controlled by the eastern provenance, mainly developed near the uplift at the north and south ends. The provenance influences and controls the development types and plane distribution of the sedimentary system from the source.

Key words: Xujiaweizi, Xuxi?Xunan area, Shahezi formation, Paleo?provenance system, Sedimentary system

摘要： 综合应用重矿物、地震属性、砂地比、古地貌等相关资料，从不同的角度、不同的层次出发，对徐西⁃徐南地区沙河子组的古物源体系特征系统的进行了分析。研究表明，徐西⁃徐南地区沙河子组主要发育有东、西两大物源体系，其中西侧徐西断阶带物源供源强度更大、影响范围更广，是研究区的主要物源方向。东部物源影响范围较小，主要集中在靠近南北两端处，是次要物源方向。总的来看，研究区物源方向有从东、西两侧指向中部的特点。研究区沙河子组主要发育扇三角洲、辫状河三角洲和湖泊沉积体系，扇三角洲沉积主要受西部徐西断阶带物源控制，沿断阶带均匀分布；辫状河三角洲沉积受东部物源控制，主要在南北两端靠近凸起处发育；物源从根源上影响和控制了沉积体系的发育类型及平面展布规律。

关键词: 徐家围子, 徐西?徐南地区, 沙河子组, 物源体系, 沉积体系