Collaborative Research: RUI: Age, Petrology, and Tectonic Setting of Purported Taconic-aged plutons, Ashland-Wedowee-Emuckfaw Belt, Southern Appalachians

哥伦布州立大学和佛罗里达大学的研究人员之间的合作项目旨在解决相互矛盾的解释的构造起源和年龄的一些变质花岗岩在阿什兰-韦多威-Emuckfaw带（东部蓝岭）的亚拉巴马省在阿巴拉契亚山脉的最南端。 传统上被认为是与塔康尼克造山带有关的最新寒武纪-中奥陶世岩浆活动，埃尔卡哈奇石英闪长岩、扎纳片麻岩和科瓦利加片麻岩被一些工作者认为是位于北美俯冲边缘之上的塔康尼克岛或劳伦特弧的一部分。 然而，从Elkahatchee的主要石英dialectics组件的SHRIMP-RG结果，建议上泥盆统侵位年龄与丰富的捕虏晶遗传的相当多的证据，这可能复杂的初始全岩和多颗粒分析完成了二十多年前。 在Elkahatchee的显着的三叠纪岩浆成分的潜力提出了疑问，它与塔康尼克弧的关联;一个问题，只能解决的各种岩性的详细同位素分析通常分配给这个岩基。 此外，由于Zana和Kowaliga片麻岩都是使用与Elkahatchee最新寒武纪年龄相同的技术进行年龄分配的，因此将这些岩体归因于奥陶纪造山作用也是可疑的。 这些岩体的空间分辨U-Pb分析将为研究锆石组分的Lu-Hf系统提供最佳的时间背景，并将使我们能够限制母岩浆的岩石构造演化，该项目的结果将为北美边缘的构造演化和阿巴拉契亚山脉的发展提供新的认识。 重要的是，它将提供新的限制有关的南阿巴拉契亚造山带的演变的基本问题，因为它的关系的连续性和性质的俯冲沿着北美东部边缘在关闭的Iapetus和Rheic海洋。 这些结果也将提供一个更好的了解重要的深成元素在阿巴拉契亚山脉南部的演变，这将有利于在该地区的本科和研究生教学的许多机构的作用。 这些大学的学生和教师专业知识和机会的整合将对培养专业地球科学家产生重大影响，他们对发展强大的国家STEM劳动力至关重要，并将通过本科院校研究计划（RUI）为主要本科院校的教师研究计划提供宝贵的支持。 最后，这个项目将提供一组地质本科生的宝贵经验（从现场到分析），通过参与地质研究计划，大大提高他们的本科教育，提高国家？STEM劳动力。

This collaborative project between investigators at Columbus State University and the University of Florida aims to resolve conflicting interpretations of the tectonic origin and age of a number of metamorphosed granitoids in the Ashland-Wedowee-Emuckfaw belt (Eastern Blue Ridge) province of Alabama in the southernmost Appalachians. Traditionally attributed to latest Cambrian-Middle Ordovician magmatism associated with the Taconic orogeny, the Elkahatchee Quartz Diorite, Zana Gneiss, and Kowaliga Gneiss have been considered by some workers to be part of an obducted Taconic island or peri-Laurentian arc emplaced atop the subducting margin of North America. SHRIMP-RG results from the dominant quartz diorite component of the Elkahatchee, however, suggest an Upper Devonian emplacement age with considerable evidence for abundant xenocrystic inheritance which may have complicated the initial whole rock and multi-grain analyses completed over two decades ago. The potential for significant Acadian-aged magmatic components in the Elkahatchee calls into question its association with a Taconic arc; a question which can only be addressed by detailed isotopic analysis of the various lithologies typically assigned to this batholith. Furthermore, since both the Zana and Kowaliga gneisses were assigned ages using some of the same techniques as those used to assign a latest Cambrian age to the Elkahatchee, attribution of these plutons to Ordovician orogenesis is also suspect. Spatially resolved U-Pb analysis of these plutons will provide the best temporal context for examining the Lu-Hf systematics of zircon components and, in combination, will allow us to constrain the petrotectonic evolution of parental magma(s).Results from this project will shed new light on the tectonic evolution of the North American margin and the development of the Appalachian Mountains through the Paleozoic. Significantly, it will provide new constraints on fundamental questions regarding evolution of the southern Appalachian orogeny because of its bearing on the continuity and nature of subduction along the eastern margin of North America during the closure of the Iapetus and Rheic oceans. These results will also afford an improved understanding of the role of important plutonic elements in the evolution of the southern Appalachians, which will be of advantage to many institutions in the region for undergraduate and graduate instruction. Integration of student and faculty expertise and opportunities at these universities will have a significant impact on training professional geoscientists, who are critical to developing a strong national STEM workforce, and will provide valuable support for a faculty research program at a predominantly undergraduate institution through the Research in Undergraduate Institutions program (RUI). Finally, this project will afford a group of geology undergraduates an invaluable experience (from field to analytical) through participation in a geological research program, greatly enhancing their undergraduate education and enhancing the nation?s STEM workforce.