Cretaceous-Paleogene Foraminiferida of the Victoria Land Basin (Cape Roberts Project)

该奖项支持对罗伯茨角项目（CRP）钻探岩心中有孔虫的特征进行研究。CRP将在罗斯海西南部的一个长达500米深的海冰平台上钻四个洞。地球物理现场调查表明，4个钻孔将提供约1500m的岩心总厚度，跨度约100 ~ 30 Ma（白垩纪-古新世）。在罗斯海或东南极洲的原位地层剖面中，这一地质时间间隔尚未得到记录。最近的白垩纪和古新世的综合数据来源出现在新西兰、南极半岛北部和南大洋。在钻探过程中，将使用岩心中的底栖生物和浮游有孔虫，以及其他化石组的数据来提供现场年龄和地层控制。将根据南大洋钻探地点的DSDP/ODP生物地层学以及新西兰浮游生物和底栖生物的分区/阶段方案进行年龄相关性分析。这项工作的一项主要任务是在项目的初步报告中记录现有有孔虫材料的全面统计，以便协助规划钻探后的调查。要记录的有孔虫的基本信息包括：存在、丰度、保存、物种优势和多样性、地层分布、动物群中地方性或世界主义的程度、种群结构的完整性或破碎性等等。这些数据将用于解决各种地质问题。不整合面和声波反射面横跨裂谷系统盆地，预计也会在钻孔中遇到。由压实和/或裂谷边缘断裂引起的主要盆地沉降/隆起趋势将从底栖有孔虫测深指标中推断出来。底栖物种地层分布中更微妙的旋回性将用于识别和记录海侵和退行阶段，这反过来可能表明海平面振荡与陆地冰川事件之间的关系。白垩纪-古新世是冈瓦纳大陆最终解体的时期，特别是新西兰和澳大利亚从南极洲向北移动的时期。从CRP钻孔中发现的有孔虫将有助于了解东南极洲高地和太平洋边缘（原横贯南极山脉的位置）之间的古地理和古海洋学，以及该疑似岛链和西南极洲高地之间的西南极洲裂谷系盆地。这将有助于回答这样一个问题：在计划钻探孔附近的东南极洲的海洋边缘是否位于白垩纪的死胡同，或者它是否有时占据西南印度洋、西南太平洋和西南大西洋之间主要海洋环流通道的位置。

Abstract This award supports efforts to characterize the foraminifera in drill core recovered by the Cape Roberts Project (CRP). The CRP will drill four holes, from a sea-ice platform in up to 500m of water, in the southwest Ross Sea. Geophysical site surveys suggest that the four drill holes will provide an aggregate thickness of about 1500m of core and span about 100 to about 30 Ma (Cretaceous-Paleocene). This interval of geological time is not yet documented by in situ stratigraphic sections in either the Ross Sea or East Antarctica. The nearest comprehensive data sources for the Cretaceous and Paleocene) occur in New Zealand, the northern Antarctic Peninsula and the southern ocean. Benthic and planktic Foraminiferida from the core will be used, together with data from other fossil groups, to provide on-site age and stratigraphic control as drilling progresses. Age correlations will be made with DSDP/ODP biostratigraphy from southern Ocean drill sites, and also with New Zealand planktic and benthic zonal/stage schemes. A principal task of this work is to document in the project's initial report, a comprehensive accounting of foraminiferal material present so as to assist planning of post-drilling investigations. Basic information to be recorded on the foraminifera will include: presence, abundance, preservation, species dominance and diversity, stratigraphic distribution, levels of endemism or cosmopolitanism in faunas, and completeness or fragmentation of population structures, et cetera. These data will be used to address a variety of geological problems. Disconformities and acoustic reflectors which extend across the rift system basins and are also expected to be encountered in the drill hole will be dated. Major basin subsidence/uplift trends resulting from compaction and/or rift margin faulting will be deduced from benthic foraminiferal bathymetric indicators. More subtle cyclicity in the stratigraphic distribution of benthic species will be u sed to recognize and document phases of transgression and regression, which in turn may indicate a relationship between sea level oscillation and terrestrial glacial events. The Cretaceous- Paleocene was an interval of time during which the final disintegration of Gondwanaland occurred, specifically the northward movement of New Zealand and Australia away from Antarctica. Foraminifera from the CRP drill holes will contribute to an understanding of the paleogeography and paleoceanography between the highlands and Pacific margin of East Antarctica (the location of the proto-Transantarctic Mountains), and the West Antarctic Rift System basins between this suspected island chain and the highlands of West Antarctica. This will help answer the question as to whether the marine margin of East Antarctica, in the vicinity of the planned drill holes, was located in a Cretaceous cul-de-sac, or whether it occupied, at times, a position on a major oceanic circulation pathway between the SW Indian Ocean, SW Pacific, and SW Atlantic Oceans.