方正断陷古近系重矿物组合特征与物源方向探讨

ANALYSIS OF THE HEAVY MINERALS CHARACTERS AND PROVENANCE DIRECTION OF PALEOGENE IN FANGZHENG FAULT DEPRESSION

查明研究区物源方向对于砂体展布、储集层预测和圈闭评价有重大意义。本文通过对方正断陷古近系新安村+乌云组、达连河组、宝泉岭组重矿物组合特征研究,并结合重矿物ZTR指数分析结果和区域构造演化特征,明确研究区古近系沉积物源主要来源于断陷西、西北、东南和东北四个方向。各物源体系重矿物组合特征及其含量反映的物源属性均存在较大的差异,在平面上以伊汉通断裂为界呈南北分带性,垂向上重矿物组合及物源方向有较大的继承性,ZTR指数从大到小的变化规律表明断陷经历了从断陷初期远物源到断坳转换期近物源的演化过程。

Find out the provenance direction in study area for the sandbody distribution、 reservoir prediction and the trap evaluation is great significance.Based on the Fangzheng fault depression Xinancun＋Wuyun Formation,Dalianhe Formation,Baoquanling Formation of heavy mineral assemblages,combined with heavy mineral ZTR index analysis results,the regional tectonic evolution.Pointed out that the provenance of the Paleogene mainly from the west,northwest,southeast and northeast four directions.there is a big difference in the provenance system and the content of heavy mineral assemblages reflect the source attributes.In the plane to Yihantong fracture is bounded remarkable characteristic of zoning,vertical heavy minerals and provenance has certain inheritance,the ZTR index changes of descending that t the Fangzheng fault depression experienced from broke the falling initial period far provenance to break the transformation time is approaching provenance evolutionary process.