广西十万大山中生代盆地充填序列及构造原型

Study of the Mesozoic Filling Sequence and Tectonic Prototype Restoration of the Shiwandashan Basin, Guangxi

为解剖十万大山盆地,对钦州盆地进行了路线控制并做了对比研究。十万大山盆地接受了从上三叠统至白垩系的较为完整的以陆相碎屑岩堆积为主、底部夹浅海-泄湖相碎屑岩的盆地沉积,主要为洪积扇相、河流相、湖泊相和沼泽相;钦州盆地接受了下-上侏罗统陆相碎屑岩-红层沉积,主要为河流相、湖泊相和河流三角洲相。在横切十万大山盆地和钦州盆地的东西向路线上,测得71个指示古水流方向的方位,表明平垌组一段古水流方向为北东→南西向,反映了一个海进过程。平垌组二段出现典型陆相红层堆积,反映了海退过程,自此十万大山盆地完全进入陆相沉积环境。并且对十万大山盆地和钦州盆地进行了构造原型恢复的研究。

This article has a discussion on Mesozoic filling sequence and tectonic prototype recovery of the Shiwandashan Basin, Guangxi. The Shiwandashan basin in the Mesozoic received almost continues clastic deposits from Later Triassic to Cretaceous with the bottom sediments of shallow lacustrine clastic rocks. Sedimentary facies in the Shiwandashan basin are mainly alluvial fan, fluvial, lacustrine and swamp facies. The Qinzhou basin received Jurassic continental clastic and red beds deposition with fluvial, lacustrine and delta facies. 71 paleocurrent direction indicators were measured in the east-west sections of the Shiwandashan basin and the Qinzhou basin, showing a northeast-southwestern transgression direction during the early Pingdong age. The continental red beds deposition appears in the Second Member of the Pingdong Formation, indicating a marine regression progress when the Shiwandashan basin developed to an entire continental sediment environment thence. The relevant tectonic prototype restoration is made.