The onshore intracratonic Cooper Basin of eastern Australia developed during the Late Pennsylvanian to Middle Triassic periods at paleolatitudes of approximately 50°S within the Gondwanan sector of Pangea. Despite the wealth of data available, including the drilling of over 4,800 boreholes, there is limited knowledge about the Cooper Basin’s origins and evolution. To better understand the basin’s geological history, legacy data sets, including composite 2D seismic sections, well logs, measured sections, and 1D burial history models from the west of the basin, are integrated to reinterpret the basin’s tectonic and sedimentary evolution. Interpretation of the seismic sections and calculated subsidence rates indicates an earlier active rift phase with grabens and half-grabens that transitioned, in the latest Permian, into a regional sag phase. The evolution of tectonic styles heavily influenced the paleogeographic evolution of the basin fill and resulting depositional architecture. The basin sediments are entirely terrestrial in nature and facies reflect a transition from glacial environments in the late Pennsylvanian to warmer and drier conditions in the early Triassic. During much of the Permian the basin was underfilled and the relative low influx of fluvial sediment did not keep pace with creation of accommodation, allowing the development of extensive mire and lake systems. Coal beds are up to 30 m thick. By contrast, the basin appears to have been overfilled during the latest Permian to Triassic with rivers flowing along the central axis of the basin. The synchroneity of commencement of rifting, termination of rifting, and commencement of a sag phase within the failed rift systems of the Cooper Basin, the East Gondwana Interior Rift, and the East Australian Rift strongly suggests a continent-wide period of extension related to significant changes in plate motions during the Late Pennsylvanian to Middle Triassic.

中文翻译：

---

澳大利亚东部库珀盆地宾夕法尼亚世晚期至三叠世早期裂谷系统崩塌剖析


澳大利亚东部的陆上克拉通内库珀盆地于宾夕法尼亚纪晚期至中三叠世时期发育，位于盘古大陆冈瓦南区内南纬约 50°C 的古纬度。尽管有大量可用数据，包括钻探了 4,800 多个钻孔，但对库珀盆地的起源和演变的了解有限。为了更好地了解该盆地的地质历史，整合了来自盆地西部的复合 2D 地震剖面、测井、测量剖面和 1D 埋藏历史模型等遗留数据集，以重新解释该盆地的构造和沉积演变。对地震剖面和计算的沉降速率的解释表明，早期的活动裂谷阶段，地堑和半地堑在最近的二叠纪过渡到区域性凹陷阶段。构造风格的演变严重影响了盆地填充物的古地理演变和由此产生的沉积结构。盆地沉积物完全是陆地沉积物，相反映了从宾夕法尼亚晚期的冰川环境到早三叠世更温暖、更干燥的条件的转变。在二叠纪的大部分时间里，盆地填充不足，河流沉积物的相对较少的流入跟不上住宿的创造，从而允许开发广泛的泥沼和湖泊系统。煤层厚达 30 m。相比之下，在最近的二叠纪至三叠纪期间，该盆地似乎已经被过度填充，河流沿着盆地的中轴线流淌。 在库珀盆地、东冈瓦纳内陆裂谷和东澳大利亚裂谷的失败裂谷系统中，裂谷开始、裂谷终止和凹陷阶段开始的同步性强烈表明，在宾夕法尼亚晚期至中三叠世期间，与板块运动的重大变化有关的大陆范围的延伸期。