Biostratigraphic and paleogeographic utility of Cambrian-Ordovician trilobite faunas in Alaska

阿拉斯加寒武纪-奥陶纪三叶虫动物群的生物地层学和古地理学应用约翰·泰勒，印第安纳州宾夕法尼亚大学-1325333摘要北美古地理图描绘了地球历史上某些时期出现的我们的大陆，地质学家利用它来探索化石燃料和其他重要的社会资源，气候专家寻求更深入地了解我们星球在“深时间”中的普遍条件，地球科学家研究构造板块的行为和塑造我们星球表面的衍生过程。 但是，在寒武纪和奥陶纪（温室气候时期），用于绘制这类地图的数据对于大陆的北方和整个北极地区来说是极其稀少的。 该项目将通过详细研究来自阿拉斯加北方北极阿拉斯加地体和阿拉斯加东部育空地区稳定地块的寒武纪-奥陶纪三叶虫（已灭绝的海洋节肢动物）动物群，改善这一状况。它将利用美国和加拿大地质调查局地质学家在过去世纪存档的大量化石收藏，并辅以在阿拉斯加几个关键地区收集的新材料。 AAT的目标是测试，通过比较新发现的动物群从其北坡Suburbine（NST）与三叶虫以前报道的苏厄德地体（ST）在阿拉斯加西部，厚的石灰岩连续NST沉积在东北部（现代坐标）北美的某个地方，而ST起源于西伯利亚或附近的假设。 在YSB中，对琼斯岭石灰岩中的岩石和化石进行全面的记录，将改善与其他地区同龄岩石的相关性。对于许多作为研究目标的层位来说，琼斯岭的数据将是从整个大陆北方获取的第一批信息。 通过这种厚（约。在北美西北角附近保存的450米）石灰岩堆将用于测试在美国和加拿大南部广阔地区记录的许多事件的大陆范围（也许是全球范围）的主张，在大陆的另一边。 这些包括（除其他外），1）海平面的一些显著上升和福尔斯和2）在寒武纪晚期的后期边界沉积中，整个平台范围内的微生物礁发育受到抑制。 拟议项目的科学成果将通过增进对北极地区的了解而造福社会，北极地区拥有丰富的重要资源，但就我们对其构造历史的基本方面的理解而言，仍然是一个前沿领域。 本科地质学专业和地球与空间科学教育专业的学生作为初级合作者广泛参与该项目，将培养出一批具有非凡洞察力的专业地球科学家和中学教师，他们能够以实际从事科学工作的人的热情和知识教授科学。

Biostratigraphic and paleogeographic utility of Cambrian-Ordoviciantrilobite faunas in Alaskaby John Taylor, Indiana University of PennsylvaniaEAR-1325333ABSTRACTPaleogeographic maps of North America, which depict our continent as it appeared at certain times in Earth history, are utilized by geologists exploring for fossil fuels and other critical societal resources, climate specialists seeking greater insight to conditions that prevailed on our planet in 'deep time', and geoscientists investigating the behavior of tectonic plates and derivative processes that shape the surface of our planet. But the data for constructing such maps for the Cambrian and Ordovician Periods, a time of greenhouse climate, are exceedingly sparse for the northern half of the continent, and the Arctic regions in general. This project will improve that situation through detailed study of Cambrian-Ordovician trilobite (extinct marine arthropod) faunas)from the Arctic Alaska Terrane (AAT) of northern Alaska, and the Yukon Stable Block (YSB) of eastern Alaska. It will utilize large fossil collections archived by geologists of the U.S. and Canadian Geological Surveys over the past century, supplemented by new material collected in several key areas in Alaska. The goal for the AAT is to test, by comparing newly discovered faunas from its North Slope Subterrane (NST) with trilobites previously reported from the Seward Terrane (ST) in western Alaska, the hypothesis that the thick limestone succession in the NST was deposited somewhere in northeastern (modern coordinates) North America, whereas the ST originated in or near Siberia. In the YSB, thorough documentation of rocks and fossils in the Jones Ridge Limestone will refine correlation with rocks of the same age in other regions. For many of the horizons targeted for study, the data from Jones Ridge will be the first information acquired from the entire northern half of the continent. The refined time control through this thick (ca. 450m) stack of limestone preserved near the northwestern corner of North America will serve to test the claim of continent wide (and perhaps global) extent for numerous events documented across broad areas in the U.S. and southern Canada, on the opposite side of the continent. These include (among others), 1) a number of significant rises and falls in sea level and 2) episodes of platform-wide suppression of microbial reef development in the aftermath stage boundary extinctions in the late Cambrian. The scientific results of the proposed project will benefit society by advancing knowledge of the Arctic region, an area rich in vital resources but still a frontier with respect to our understanding of even basic aspects of its tectonic history. Extensive involvement of undergraduate Geology majors and Earth and Space Science Education majors as junior collaborators in the project will produce a cadre of professional geoscientists with exceptional insight and secondary school teachers able to teach science with the enthusiasm and knowledge of someone who has actually done science.