Evaluating The Effects Of The Alamo Impact Event On Carbonate Platform Recovery And Regional Tectonics: A Research Focus For Educators In The Great Basin

评估阿拉莫撞击事件对碳酸盐台地恢复和区域构造的影响：爱达荷州立大学大盆地教育工作者的研究焦点晚泥盆世(382 Ma)阿拉莫撞击事件是由一次公里尺度的火流星撞击引起的，它摧毁了大盆地中200公里长的扩张的碳酸盐台地。事件发生后不久，动物群对阿拉莫撞击角砾岩的表面进行了重新殖民，没有任何生物灭绝或任何长期的环境地球化学变化的证据。因此，阿拉莫撞击事件可以与中等频率(103-106年)的灾难性物理事件相媲美，例如大风暴、海啸和其他影响碳酸盐平台演化的温和的火流星撞击。该项目将对内华达州南部的Guilmette地层进行详细的野外测绘，以提供阿拉莫事件之前、期间和之后的第一个高分辨率地台地层3D模型，并使特定地点的撞击特征与上覆的恢复要素相关联。该项目的目标包括：(1)测试和改进目前的海洋目标影响模型；(2)评估大盆地一条主要东西向构造构造假想的泥盆纪活动；(3)根据阿拉莫撞击事件留下的海底物理属性，评估动物群重新殖民化和相演变。这些目标将以一种新颖的方式实现，方法是使用最初为采矿业设计的Vulcan地理信息系统软件，从内华达州东南部露头暴露的100多个Guilmette组地层剖面中汇编地层厚度、古水流、沉积和古生物属性。根据这些数据制作的地图将用于确定阿拉莫角砾岩亚单元的沉积路径和沉积中心；计算撞击挖掘及随后的泥石流和海啸沉积造成的岩石体积净位移；以及重建研究区域内撞击后海底地形和相对水深。将在撞击沉积物上方收集的沉积、动物群和生物数据与撞击后海底的基本物理参数进行比较，例如地形、相对水深、底物类型和地理位置，以确定碳酸盐台地生态系统短期(100年)和长期(~500kyr)恢复的变化。阿拉莫的研究将包括对两名研究生进行实地地质学和地理信息系统应用方面的培训。更重要的是，研究活动将与通过大盆地实地地质学影响倡议开展的全面教育宣传工作相结合。与美国教育部在内华达州和爱达荷州的Gear Up项目合作，我们的Impact Initiative包括一个四管齐下的方法，为K-12教师和学生提供STEM教育和培训机会，重点是让女高中生参与研究。

Evaluating The Effects Of The Alamo Impact Event On Carbonate Platform Recovery And Regional Tectonics: A Research Focus For Educators In The Great BasinLeif Tapanila, Idaho State University The Late Devonian (382 Ma) Alamo Impact Event was caused by a km-scale bolide impact that devastated a 200 km portion of the expansive carbonate platform in the Great Basin. Shortly following the event, faunas recolonized the surface of the Alamo impact breccia without any evidence for biotic extinctions or any long-lived geochemical change to the environment. As such, the Alamo Impact Event is comparable to moderately frequent (103-106 yr) catastrophic physical events, such as large storms, tsunamis, and other modest bolide impacts, that shape carbonate platform evolution. This project will conduct detailed field mapping of the Guilmette Formation in southern Nevada to provide the first high resolution 3D model of platform strata before, during and after the Alamo Event and allow site-specific correlation of impact features with overlying elements of recovery. Objectives of the project include (1) testing and refining the current model for marine-target impacts; (2) assessing the hypothesized Devonian activity of a major E-W structural lineament in the Great Basin; and (3) evaluating faunal recolonization and facies evolution as a function of the physical attributes of the seafloor left by the Alamo impact event. These objectives will be accomplished in a novel way by using Vulcan GIS software, originally designed for the mining industry, to compile stratigraphic thickness, paleocurrent, sedimentary and paleontological attributes from more than 100 stratigraphic sections of the Guilmette Formation exposed in outcrops of southeast Nevada. Maps produced from these data will be used to identify depositional pathways and depocenters of Alamo Breccia subunits; to calculate net rock volume displacement from impact excavation and subsequent debris-flow and tsunami deposition; and to recreate the post-impact seafloor topography and relative bathymetry in the study area. Sedimentary, faunal and ichnological data collected above the impact deposits will be compared to underlying physical parameters of the post-impact seafloor, e.g., topography, relative bathymetry, substrate type, and geographic position, to identify variations in short-term (100 yrs) and long-term (~500 kyrs) recovery of the carbonate platform ecosystem. The Alamo research will involve the training of two graduate students in field geology and GIS applications. More significantly, research activities will merge with a comprehensive educational outreach effort through the Impact Initiative on Great Basin Field Geology. Partnering with the U.S. Department of Education's GEAR UP programs in Nevada and Idaho, our Impact Initiative includes a four-pronged approach to provide STEM education and training opportunities to K-12 teachers and students, with an emphasis on involving female high school students in research.