苏北三垛组游荡性河与低弯度河沉积特征

SEDIMENTARY CHARATERS OF BRAIDED AND LOW—SINUOSITY STREAMS IN SANDO FORMATION OF LOWER TERTIARY, NORTHERN JIANGSU PROVINCE

董荣鑫

Dong Rongxin

同济大学海洋地质系

Marine Geology Department, Tongji University

古河流的沉物中常含有金、金刚石、铀、铂、独居石等稀有贵金属矿床以及形成重要的油气储层。因此,对古代河流沉积物的研究具有很大的现实意义。目前,对曲流河的研究较深入,而对游荡性网状河沉积的研究却不够。为探讨后者的沉积特征,特别是寻求在古代地层剖面中识别它们的标志,本文以苏北盆地三垛组一段的冲积相为例,论述了它们的沉积特征,讨论了游荡性网状河和低弯度河沉积的对比,并选出了典型的实测剖面作为剖面模式。

In the sediments of paieostreams,there are certain amount of rare mineral deposits,such as gold,diamond,uranium,platinum and monazite,etc.and some important oil/gas reservoirs as well.Therefore,it is practi-cally significant to study the ancient fluvial sediments.Up to the present,much analysis have been made on the sedimentation of the sinuous streams,but those on braided streams are not enough.Taking Lower Tertiary fluvial sedimentation in Sando Formation of Northern Jiangsu as an example,the characters of fluvial sedimentation,and the relation between braided streams and low-sinuosity streams are discus-sed in this paper.For the recognition of the sedimentary characters of such streams,especially of the characters in ancient stratigraphic profiles,the author of this paper establishes a typical profile as a model.

https://doi.org/10.11781/sysydz198704374