Three-dimensional seismic geomorphology and sedimentology of heterozoan and photozoan carbonate systems, Browse Basin, NW Australia

澳大利亚西北陆架的Browse盆地为研究始新世碳酸盐陆架的近代史提供了难得的视角，该陆架由冷水斜坡发展为热带边缘台地。这一变化的碳酸盐岩体系的地下特征记录在高分辨率三维反射地震调查中，覆盖了100 000平方公里，24000公里的区域二维反射地震线，以及8口探井的电缆测井和岩心。对这一综合数据集的详细分析将用于解决目前正在讨论的碳酸盐岩平台开发的三个关键方面：方面1 -冷水碳酸盐岩的斜坡侵蚀是否主要由斜坡倾斜或海平面波动控制是一个悬而未决的问题。本研究获得的三维地震体提供了全三维空间控制，可以分析海平面变化、陆架形态和斜坡侵蚀之间的关系。从无边缘的冷水斜坡到边缘的热带碳酸盐岩台地的转变尚未在三维地震数据中被记录下来，而区域二维研究的例子也很少见。高分辨率3D分析与详细的电缆和岩心研究相结合，将支持此类转换的普遍适用模型的开发。第三方面：岩心、电缆测井和3d地震特性的综合分析将有助于解决淹没期间热带碳酸盐陆架的内部结构。三维地层正演模拟将用于地下解释结果的定量评估，最终支持在类似但勘探较少的环境中预测碳酸盐岩相。该研究项目的结果有望有助于更好地理解冷水和热带碳酸盐平台的内部结构和外部形式，并阐明形成这些对比系统的关键过程。

The Browse Basin on the North West Shelf, Australia, provides a rare insight into the Eocene to recent history of a carbonate shelf that developed from a cool-water ramp to a tropical rimmed-platform. Subsurface signatures of this variable carbonate system are recorded on high-resolution 3D reflection-seismic surveys covering > 1000 km2, 24.000 km regional 2D reflection-seismic lines, as well as on wireline logs and cores of 8 exploration wells. A detailed analysis of this comprehensive dataset will be used to address three key aspects of carbonate-platform development that are currently under discussion: Aspect 1 - It is an open question whether slope erosion in cool-water carbonates is dominantly controlled by slope inclination or sea-level fluctuations. Full 3D spatial control provided by the 3D seismic volume acquired for this study allows the analysis of the relationship between sea-level change, shelf morphology and slope erosion. Aspect 2 - The transition from an unrimmed cool-water ramp to a rimmed tropical carbonate platform has not yet been documented in 3D seismic data, and examples from regional 2D studies are rare. High-resolution 3D analysis in combination with detailed wireline and core studies will support the development of a generally applicable model for such transitions. Aspect 3 – The combined analysis of cores, wireline logs and 3D-seismic properties will contribute to resolve the internal architecture of the tropical carbonate shelf during drowning. 3D stratigraphic forward modelling will be used for a quantitative evaluation of the subsurface interpretation results, ultimately supporting the prediction of carbonate facies in similar but less explored settings. Results of this research project are expected to contribute to a better understanding of the internal architecture and external form of cool-water and tropical carbonate platforms, and to shed light on the key processes shaping these contrasting systems.