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

学术价值：数值和实验室模拟表明，地球发电机的动力学在切线圆柱体内外是不同的，切线圆柱体是与地球自转轴平行的假想圆柱体，与固体内核相切。高北极提供了一个理想的机会，通过收集古地磁和古强度数据来研究这些过程。首席研究员最近发现了一个由晚白垩世北极熔岩记录的地磁反转转变（该地点在熔岩就位时正好在切线柱内）。他将以这个偶然事件为例来定义pre、post和transitional字段。方向将基于整个岩石样品的古磁学分析，以及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及其边缘、与高北极（斯特兰德峡湾）大火成岩省的潜在联系以及地幔柱的作用也很重要。最后，来自同一层序的脊椎动物化石提供了重要的极地古气候信息。首席研究员将通过一种共同的实地方法对这些主题进行多学科研究：对定义明确的高北极地层剖面进行高分辨率采样。火山岩将被采集古地磁、地质年代学和地球化学样本，而化石将被收集以更好地表征晚白垩纪-古近纪的极地温度。拟议研究的更广泛影响：首席研究员预计，从切线柱内的一个地点记录的地磁反转的定义将引起对核心过程感兴趣的广泛科学家的兴趣，而对这些岩石的性质和年龄的进一步确定将对那些对北冰洋及其边缘构造发展感兴趣的科学家很重要。此外，与这些火山岩相关的脊椎动物化石的研究将引起古气候界的兴趣。该项目将支持一篇博士论文和几名本科生的研究。本科生通常参加实地工作，许多人通过自主研究项目和本科毕业论文在实验室对样品进行分析。他还计划通过向北极（努纳武特）社区展示这些发现来开展推广活动。

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.