Stratigraphy and sedimentology of Late Palaeozoic glaciomarine sediments beneath the Murray Basin, and their palaeogeographic and palaeoclimatic significance

Sediments of the Late Palaeozoic Urana Formation in infrabasins beneath the Cainozoic Murray Basin include glaciomarine diamictite, fine-grained sediment, sandstone, and conglomerate facies. The facies assemblage is dominated by paratillites, formed by ice-rafting, and fine-grained sediments with a small ice-rafted component. Rhythmically bedded siltstone and claystone, sediment gravity-flow diamictites, traction-current deposits, and, possibly, subglacial tillites are also present. Interpretation of the facies indicates that grounded-ice deposits are absent from the glaciomarine sequence over large areas of the basin and has enabled estimation of the likely limits of grounded ice. Palaeontological and sedimentological evidence suggests that these rocks were deposited towards the end of the major Late Palaeozoic glaciation of southeastern Australia.

新生代默里盆地下伏亚盆地中的晚古生代乌拉纳组沉积物，包含冰川海相混杂岩、细粒沉积物、砂岩及砾岩相。该岩相组合以浮冰搬运形成的准冰碛岩，以及含少量浮冰搬运组分的细粒沉积物为主；此外还发育韵律层理粉砂岩、黏土岩、沉积物重力流混杂岩、牵引流沉积，以及可能的冰下冰碛岩。通过对该岩相的解译可知，该盆地大片区域的冰川海相序列中并无固着冰沉积，这一结果可为固着冰的可能分布范围估算提供依据。古生物学与沉积学证据显示，这些岩石沉积于澳大利亚东南部晚古生代大冰期的末期。