Multidisciplinary Investigation of Late Cretaceous and Paleogene Stratigraphic Sequences of the High Arctic

TardunoOPP-06212379智力优势：数值和实验室模拟表明，地球发电机的动力学在切线柱体内外是不同的，切线柱体是平行于地球自转轴并与固体内核相切的虚构圆柱体。北极高原提供了一个通过收集古地磁和古强度数据来研究这种过程的理想机会。首席调查员最近发现了晚白垩世北极熔岩记录的地磁反转转变(该地点在熔岩侵位时正好在切线柱体内)。他将以这一偶然事件为样本来定义前、后和过渡领域。方向将基于对整个岩石样品的古地磁分析，以及对从熔岩中分离出的单个斜长石晶体的古强度分析。这些岩石对于了解北冰洋的构造演化、其边缘、与北极高地(斯特兰德湾)大型火成岩省的潜在联系以及地幔羽流的作用也很重要。最后，来自相同地层层序的脊椎动物化石提供了重要的极地古气候信息。首席调查员将对这些专题进行多学科研究，这些专题通过一种共同的实地方法联系在一起：对明确界定的北极高地层段进行高分辨率采样。将对火山岩进行古地磁、年代学和地球化学采样，同时将收集化石以更好地描述晚白垩世-古近纪极地温度。拟议研究的广泛影响：首席调查者预计，从正切圆柱体内的某个地点记录的熔岩中记录的地磁逆转的定义将引起对岩芯过程感兴趣的广泛科学家的兴趣，而进一步确定这些岩石的性质和年龄将对那些对北冰洋及其边缘的构造发展感兴趣的人非常重要。此外，与这些火山岩相关的脊椎动物化石的研究将会引起古气候界的兴趣。这个项目将支持一篇博士论文和几个本科生的学习。本科生通常参加实地考察工作，许多人通过独立的研究项目和本科高级论文在实验室进行样本分析。他还计划通过向北极(努纳武特)社区展示调查结果来开展外展活动。

ABSTRACT TardunoOPP-06212379Intellectual merit: Numerical and laboratory simulations suggest that thedynamics of the geodynamo differ inside and outside the tangent cylinder, that imaginary cylinder parallel to Earth's spin axis and tangent to the solid inner core. The High Arctic provides an ideal opportunity to investigate such processes through the collection of paleomagnetic and paleointensity data. The Principal Investigator has recently discovered a geomagnetic reversal transition recorded by Late Cretaceous Arctic lavas (the site was well within the tangent cylinder during emplacement of the lavas). He will sample this fortuitous occurrence to define the pre, post, and transitional field. Directions will be based on paleomagnetic analyses of whole rock samples, and paleointensity on Thellier analyses of single plagioclase crystals separated from the lavas. These rocks are also important for understanding the tectonic evolution of the Arctic Ocean, its margins, the potential connection with the High Arctic (Strand Fiord) large igneous province and the role of mantle plumes. Finally, vertebrate fossils from the same stratigraphic sequences have yielded important polar paleoclimate information. The Principal Investigator will conduct a multidisciplinary study of these topics linked by a common field approach: high resolution sampling of well-defined High Arctic stratigraphic sections. Volcanic rocks will be sampled for paleomagnetism, geochronology and geochemistry, whereas fossils will be collected to better characterize Late Cretaceous-Paleogene polar temperatures.Broader impacts of the proposed research: The Principal Investigator expects that the definition of a geomagnetic reversal recorded in lavas from a site within the tangent cylinder will be of interest to a broad range of scientists interested in core processes, while further determinations of the nature and age of these rocks will be important for those interested in the tectonic development of the Arctic Ocean and its margins. In addition, the study of vertebrate fossils associated with these volcanic rocks will be of interest to the paleoclimate community. This project will support a Ph.D. thesis and the studies of several undergraduate students. Undergraduates typically take part in the field work, and many conduct analyses of samples in the laboratory through independent study projects and undergraduate senior theses. He also plans outreach activities by presenting the findings to Arctic (Nunavut) communities.