Understanding basin sedimentary provenance: evidence from allied phytogeographic and heavy mineral analysis of the Palaeocene of the NE Atlantic

The drilling of hydrocarbon exploration wells in the Faroe–Shetland Basin has provided an expanding sample resource that provides material for testing recently developed palynology-based sediment transport analysis. This technique has been verified by comparison with heavy mineral analysis; both approaches have been used to identify sediment sources and input points along the strike of the Palaeocene West Shetland Platform. Integration of heavy mineral and palynological data has provided a basis for understanding arenaceous and argillaceous sediment distribution and sourcing. In addition to a source from the western, Greenland side of the basin, four argillaceous and four arenaceous sedimentary sources have been identified along the strike of the West Shetland Platform. These vary in temporal and spatial distribution, and thus provide a history of sediment source evolution. This analysis supports a persistent difference in source between the Corona Basin and the Flett and Judd Sub-basins. Although source variation and overlap between basins is evident, transfer zones represent both conduits for and barriers to effective sediment transport. Both palynological and heavy mineral evidence identifies the former presence of Late Namurian–Westphalian strata on the West Shetland Platform, which were removed by subsequent erosion.

法罗-设得兰盆地（Faroe–Shetland Basin）的油气勘探井钻探工作持续扩充了样本资源储备，为新近开发的基于孢粉学的沉积物输运分析（palynology-based sediment transport analysis）方法的验证提供了实验材料。该技术已通过与重矿物分析（heavy mineral analysis）的对比得到验证；两种方法均被用于识别古新世西设得兰台地（Palaeocene West Shetland Platform）走向方向上的沉积物源与输入点。重矿物与孢粉学数据的整合，为理解砂质与泥质沉积物的分布及物源提供了研究基础。除盆地西侧格陵兰一侧的物源外，研究人员在西设得兰台地的走向方向上还识别出4处泥质沉积物源与4处砂质沉积物源。这些物源在时空分布上存在差异，由此揭示了沉积物源的演化历史。本分析证实，科罗纳盆地（Corona Basin）与弗莱特及贾德次级盆地（Flett and Judd Sub-basins）的物源始终存在差异。尽管不同盆地间的物源存在变化与重叠，但转换带（transfer zones）既是沉积物有效输运的通道，也是其阻隔屏障。孢粉学与重矿物两方面的证据均表明，西设得兰台地上曾存在纳缪尔晚期-威斯特伐利亚期地层（Late Namurian–Westphalian strata），但该地层后续被侵蚀作用移除。