鄂尔多斯周缘奥陶纪海相红层的分布与时代

海相红层是红层研究的一个重要方向,在前人地层学、古生物学等资料基础上,笔者在鄂尔多斯周缘露头区针对奥陶纪海相红层进行了专门研究,从中识别出7套奥陶纪海相红层。借助于对应地层中已报道的笔石、三叶虫、珊瑚等不同化石类别的特征分子、典型化石带或化石组合,基本确定了这7套海相红层的形成时代:自下而上分别为特马豆克期、弗洛期晚期(也许包括大坪期早期)、大坪期、达瑞威尔期、桑比期、凯迪期早期和凯迪期晚期。建立了鄂尔多斯周缘奥陶纪海相红层对比表,分析了奥陶纪海相红层形成环境和古地理分布情况。

Distribution and Ages of Ordovician Marine Red Beds around Ordos Basin

Based on previous work on stratigraphy and paleontology, the authors recognized 7 Ordovician marine red beds through a specialized study around Ordos Basin. The ages of these marine red beds confirmed by means of zone fossil, typical fossil zone or fossil assemblages of graptolite, Trilobita and coral in the interior or nearby places are in upward succession Tremadocian, late Floian (probably including early Dapingian), Dapingian, Darriwilian, Sandbian, early Katian and late Katian. The correlation of Ordovician red beds around Ordos Basin was erected, followed by a discussion on the paleoenvironment and distribution of these red beds.