The Cape Roberts Project: Volcanic Record, Geochemistry and 40Ar/39Ar Chronology

凯尔OPP 9527329摘要罗伯茨角项目是一项国际钻探项目，目的是从罗斯海罗伯茨角附近海底的沉积地层中获取一系列岩心。该项目是由来自德国、意大利、新西兰、英国、澳大利亚和美国的国家南极计划的科学家联合开展的。钻探将连续取心超过1500米厚的复合沉积物段，预计将代表3000万年至1亿多年前的部分时间段。该项目这一部分的主要目标将是检查钻芯中的火成岩记录，并提供来自火山灰(火山灰)层、浸染灰、长石和碎屑火山碎屑颗粒的高精度40Ar/39Ar测年，以限制岩心中沉积物的沉积年龄和来源。该项目将有助于岩芯的一般地质记录，并将使用电子微探针、X射线荧光(XRF)和仪器中子活化分析(INAA)分析任何火成岩物质的特征。新生代麦克默多火山的碱性火山碎屑的存在将限制这一阶段火山作用的开始，并提高我们对火山作用和构造作用之间关系的理解。来自侏罗纪柯克帕特里克玄武岩和费勒玄武岩侵蚀的沉积物的涌入将被用来计算横贯北极山脉的剥离和抬升速度。岩心样品的地球化学分析将检查沉积物的地球化学性质和来源。

Kyle OPP 9527329 Abstract The Cape Roberts Project is an international drilling project to obtain a series of cores from the sedimentary strata beneath the sea floor off Cape Roberts in the Ross Sea. The project is a joint venture by scientists from the national Antarctic programs of Germany, Italy, New Zealand, the United Kingdom., Australia, and the United States. Drilling will continuously core a composite section of sediments over 1500 m thick which is expected to represent parts of the time period between 30 and more than 100 million years ago. The principle objectives of this component of the project will be to examine the record of igneous material in the drill core and provide high precision 40Ar/39Ar dates from tephra (volcanic ash) layers, disseminated ash, feldspars and epiclastic volcanic detrital grains to constrain depositional age and provenance of the sediments in the cores. This project will contribute to general geologic logging of the core and will characterize any igneous material using electron microprobe, x-ray fluorescence (XRF) and instrumental neutron activation analysis (INAA) analyses. The presence of alkalic volcanic detritus from the Cenozoic McMurdo Volcanics will constrain the initiation of this phase of volcanism and improve our understanding of the relationship between volcanism and tectonism. The influx of sediments eroded from Jurassic Kirkpatrick Basalts and Ferrar Dolerites will be used to time the unroofing and rates of uplift of the Transantarctic Mountains. Geochemical analyses of core samples will examine the geochemistry and provenance of the sediments.