摘要：
根据重力异常资料、地震资料，综合运用重矿物法、碎屑岩类分析法并结合砂体展布特征，基本明确了黄骅坳陷孔南地区孔店组二段的物源区位置及来源方向。区域布格重力异常场从宏观上勾绘出了孔南地区地势的起伏状况，对物源分析具有重要参考意义。在研究区湖盆周缘都发育砂体，在各物源口的砂体展布规律在平面上表现为呈扇形展布的特征，宏观上指示了物源的涉及范围。盆外下切沟槽能大致确定研究区周缘各物源口位置，前积反射结构也能指示出存在物源供给的地区。重矿物以锆石、电气石、金红石、石榴石、磁铁矿为主，不同的物源区具有不同的重矿组合特征，其变化规律指示了碎屑物质的搬运方向和搬运途径。碎屑岩组分以长石为主，其次为石英，岩屑含量较低，主要为岩浆岩岩屑，岩屑类型指示了物源区母岩类型主要为岩浆岩。该区孔店组二段沉积时期在东南、西南、西北、东北4个方向上都存在物源，进一步可识别出乌马营、叶三拔、舍女寺等10个子物源，它们共同控制了孔南地区孔店组二段沉积时期砂体的形成和分布，形成多物源环湖盆分布的特征。
关键词:
物源,
重矿物,
碎屑岩成分,
砂体展布,
孔店组二段,
黄骅坳陷
Abstract:
Based on analysis of gravity anomaly and seismic data, heavy mineral data, clastic rock data and sand body distribution were used to identify the provenance of the Member 2 of Kongdian Formation in Kongnan area, Huanghua Depression, Baihai Bay Basin. Regional Bouguer gravity anomaly field which has important referential meaning for analysis of provenance delineated the topography of Kongnan area. Sand bodies at basin margin and their fan-shaped outlines delineated the macroscopical scope of each provenance. Incised grooves surrounding the depression roughly indicated the locations of the provenances. Progradational reflection configuration on the seismic profiles confirmed the locations of the provenances. Heavy minerals included zircon, tourmaline, rutile, garnet, and magnetite. Heavy mineral assemblages and their variations indicated the directions and routes of detrital materials. Clastics consisted of abundant quartz grains, a small quantity of feldspar grains and little rock debris from the magmatic rock which was the primary source rock type. Located at the directions of southeast, southwest, northwest and northeast of the basin, the provenances were divided into ten sub-provenances at Wumaying, Yesanbo, Shenüsi and so on. These sub-provenances surrounded the lake basin and controlled the formation and distribution of sand bodies during the depositional period of Member 2 of Kongdian Formation in Kongnan area.
Key words:
provenance,
heavy mineral,
clastic rock component,
sand body distribution,
Member 2 of Kongdian Formation,
Huanghua Depression
中图分类号:
钟玮, 蒲秀刚, 何幼斌, 陈长伟, 林常梅, 韩文中, 张伟, 吴超. 渤海湾盆地黄骅坳陷孔南地区古近系孔店组二段物源分析*[J]. 古地理学报, 2012, 14(6): 707-718.
Zhong Wei, Pu Xiugang, He Youbin, Chen Changwei, Lin Changmei, Han Wenzhong, Zhang Wei, Wu Chao. Provenance of the Member 2 of Paleogene Kongdian Formation in Kongnan area，Huanghua Depression，Bohai Bay Basin[J]. JOURNAL OF PALAEOGEOGRAPHY, 2012, 14(6): 707-718.