Detrital composition of Ordovician sandstones from the Rügen boreholes: implications for the evolution of the Tornquist Ocean
Detrital composition of Ordovician sandstones from the Rügen boreholes: implications for the evolution of the Tornquist Ocean
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吕根岛钻孔奥陶纪砂岩的碎屑成分：对托恩奎斯特洋演化的影响
DOI：
10.1007/bf00210546
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
G. Katzung
中科院分区：
文献类型：
--
作者：
U. Giese;R. Walter;G. Katzung
吕根钻孔的下古生界层序由泥质-碎屑岩沉积物组成，其年龄范围从寒武-奥陶纪界线到晚奥陶纪。对Loissin钻孔的寒武-奥陶系砂岩和Rugen 5钻孔的中-上奥陶统灰岩进行了物源研究，Loissin砂岩以浊积岩和泥石流的形式沉积于不稳定的沉积盆地中。它们形成高基质含量的未成熟长石砂岩和亚长石砂岩。其碎屑来源于多旋回的沉积岩浆源区和单旋回的岩浆源区。这反映在重矿物谱中，它主要由一种非自形的有色锆石和一种自形的透明锆石组成。中-上奥陶统Rügen灰岩来自近源高能浊积岩，它们被搬运到深海盆地中。它们形成均质岩屑长石砂岩和长石岩屑砂岩。它们的碎屑物源为超镁铁质-镁铁质、蛇绿质、酸性岩浆和非均质沉积岩源的复合物源，虽然Loissin砂岩可能起源于克拉通内的裂谷型沉积盆地，但Rugen灰岩碎屑物源被认为是非均质活动大陆边缘。根据建议的下古生界古地理重建，讨论了物源研究的结果和解释。
The Lower Palaeozoic sequences of the Rügen boreholes are composed of pelitic-clastic sediments which range in age from the Cambro-Ordovician boundary to the Late Ordovician. Provenance studies have been carried out on Cambro-Ordovician sandstones from the Loissin borehole and on Middle-Upper Ordovician greywackes of the Rugen 5 borehole.The Loissin sandstones were deposited as turbidites and debris flows in an unstable sedimentary basin. They form immature arkoses and subarkoses with high matrix contents. Their debris derived from a polycyclic, sedimentary cratonic provenance and from a monocyclic magmatic provenance. This is reflected in the heavy mineral spectrum, which is dominated by an anhedral, coloured zircon fraction and a euhedral, transparent zircon fraction.The Middle-Upper Ordovician Rügen greywackes derived from proximal, high energy turbidites which were transported into a deep marine basin. They form homogeneous lithic arkoses and arkosic litharenites. Their debris derived from a composite provenance with an ultramafic-mafic, ophiolitic source, an acidic magmatic source and a heterogeneous sedimentary cratonic source.Although the Loissin sandstones probably originated in an intracratonic, rift-related sedimentary basin, the debris of the Rugen greywackes is regarded as derived from a heterogeneous active continental margin. Results and interpretations of the provenance study are discussed in the light of proposed Lower Palaeozoic palaeogeographic reconstructions.