Collaborative Research: Late Wenlock-Ludlow (Silurian) Oceanic Episodes and Events, Southern Laurentia

自1990年以来，人们提出了几个类似的全球气候和海洋变化模型，以解释志留纪地层记录的岩性、海平面、生物和地球化学事件。第一个也是最突出的一个模型是杰普森的模型，他将志留纪细分为一系列海洋状态，这些海洋状态被短暂的海洋事件隔开，在此期间发生了戏剧性的变化，包括与初级生产力下降有关的动物灭绝。几乎所有模型的详细文档都来自波罗的海地区。测试这些模型需要检查更多的志留纪事件。该团队将研究志留纪的时间跨度，其中包括两个主要事件(穆德和刘)，一个小事件(林德)和一系列海洋事件之间的变化，这些事件没有记录到重大的事件。这些数据将来自跨越南劳伦蒂亚3000公里的路段，该地位于志留纪期间远离波罗的海的地方。研究将重建跨越劳伦蒂亚南部克拉通并延伸到阿巴拉契亚造山带附近的盆地的沉积、生物和地球化学史，间隔约5.0My。这将有助于评估与水循环有关的生物和地球化学因素的地理趋势，这些因素从克拉通边缘附近穿过陆表海，进入或多或少与全球海洋连接良好并与构造事件相互作用的盆地。这将包括对志留纪海洋变化的区域表达的第一次分析，并将提供与波罗的海相关部分进行深入比较所需的详细文件。对志留纪和古生代气候和海洋变化的地层记录的性质将得到更好的理解。将保存数据，包括用于进一步分析的未经处理的样品(几丁虫、孢粉、锶同位素等)，以及可供纳入动态、互动和有时间校准的网络的信息，如Chronos项目。

Several similar models of global climate and oceanic change have been proposed since 1990 to explain lithologic, eustatic, biotic and geochemical events recorded from Silurian strata. The first, and still most prominent, of the models is that of Jeppsson, who subdivided the Silurian into a series of oceanic states separated by short-lived oceanic events, during which dramatic changes, including faunal extinctions related to drops in primary productivity, occurred. Nearly all of the detailed documentation of the models comes from the Baltic region.Testing these models requires that additional Silurian events be examined. The team will examine a span of Silurian time that includes two major events (Mulde and Lau), a minor event (Linde) and a series of shifts between oceanic episodes for which no significant 'events' have been recorded. The data will come from sections that span 3000 km across southern Laurentia, which was located distant from Baltica during the Silurian.The research will yield a reconstruction of the depositional, biotic, and geochemical history for an interval of approximately 5.0 my across the southern craton of Laurentia and extending into basins proximal to the Appalachian orogenic area. This will allow for evaluation of geographic trends in biological and geochemical factors related to water circulation from near the cratonic margin across an epeiric sea and into basins that were more or less well connected to the global ocean and were interacting with tectonic events. This will comprise the first analysis of regional expression of Silurian oceanic changes, and will also provide the detailed documentation required for in-depth comparison to sections associated with Baltica. A far better understanding of the nature of the stratigraphic record of climatic and oceanic change for the Silurian, and thereby also the Paleozoic, will result. Data will be reposited, including unprocessed samples for additional analyses (chitinozoan, palynomorphs, Sr-isotopes, etc.), and information made available for inclusion in a dynamic, interactive and time-calibrated network, such as the CHRONOS project.