Carbon Isotope Stratigraphy of the Carboniferous in the Arrow Canyon Range, Southeastern Nevada: Reconstructing Carbon Cycling during a Greenhouse-Icehouse Transition

拟议的研究将为内华达州东南部箭峡谷山脉暴露的石炭纪石灰岩提供近1.3公里的高分辨率（米级）d13C地层。经过近40年的学术、工业和政府地质学家的详细工作，箭峡谷山脉已成为石炭纪的全球参考剖面。然而，到目前为止，很少有地球化学研究可以用来解决全球过程（例如，碳循环，大陆风化）。碳同位素曲线的密西西比样品将来自钨沟剖面，宾夕法尼亚部分将来自箭峡谷剖面。这两个部分基本上没有断层，沿走向距离不到10公里。以前的工作已经利用牙形石和有孔虫为这两个剖面建立了详细的生物地层框架，这将允许在带状时间尺度内放置碳同位素曲线。先前对箭峡谷演替的下密西西比部分的碳同位素研究已经揭示了保存完好的趋势，可以在区域和全球范围内进行对比，表明箭峡谷山脉非常适合进行详细的地球化学调查。箭谷山脉石炭纪地层几乎全部为石灰岩，在密西西比纪形成了一个向上浅水的演替，在宾夕法尼亚纪形成了至少两个海侵-退回旋回，包括旋回沉积。碳同位素曲线将与北美和欧洲其他地方石炭纪的类似数据集相结合，以检验关于温室到冰窖过渡期间有机碳埋藏率和河流风化通量的全球变化的假设。

0003803Saltzman The proposed research will result in a high-resolution (meter-scale) d13C stratigraphy for nearly 1.3 km of Carboniferous limestones exposed in the Arrow Canyon Range in southeastern Nevada. The Arrow Canyon Range has served a global reference section for the Carboniferous as a result of nearly 40 years of detailed work by academic, industry and government geologists. However, little geochemistry has been done to this point that can be used to address global processes (e.g., carbon cycling, continental weathering). The Mississippian samples for the carbon isotope curve will come from a section at Tungsten Gap and the Pennsylvanian portion will come from the section at Arrow Canyon. The two sections are essentially unfaulted and separated by less than 10 km along strike. Previous work has produced a detailed biostratigraphic framework for both sections using conodont and foraminifers, which will allow for the placement of the carbon isotope curve within a zonal time scale. Previous carbon isotope study in the Lower Mississippian portion of the Arrow Canyon succession has revealed well-preserved trends that can be correlated on a regional to global scale, indicating that the Arrow Canyon Range is well-suited for a detailed geochemical investigation. Carboniferous formations in the Arrow Canyon Range are almost entirely limestone, and make up an upward-shallowing succession during the Mississippian and at least two transgressive-regressive cycles, including cyclothemic deposition, during the Pennsylvanian. The carbon isotope curve will be integrated with similar data sets generated for the Carboniferous elsewhere in North America and Europe in order to test hypotheses about global changes in organic carbon burial rates and riverine weathering fluxes during a Greenhouse to Icehouse transition.