Collaborative Research: Late Pleistocene and Earliest Holocene Evolution of the Lower Mississippi Valley

Guccione密西西比河下游河谷(LMV)有可能了解大水系的上游气候/冰川和下游海平面控制之间的联系。此外，山谷冲积地貌的地层学和年代学框架将有助于研究北部山谷内新马德里地震带内的构造活动。这项拟议的研究旨在建立晚更新世全冰期(威斯康星期晚期)至全新世早期的LMV演化的年代学和成因模型，全新世是北美水文系统发生快速大规模重组的时期。这些重新安排包括Laurentide冰盖边缘的变化、前冰川湖泊的排水和Se水平的上升。这项建议侧重于a)来自前冰缘的流量和泥沙负荷波动的作用，b)海平面流量的下游影响，以及c)这些强迫机制对LMV地貌演变的影响。我们希望解决以下问题：o LMV的地貌和沉积与冰缘变化、前冰川湖泊的洪水和/或墨西哥湾发现的特定融水和沉积物尖峰有何关联？o LMV的地貌和沉积与密西西比河流域上游的地貌和沉积有什么关联，那里的气候/冰川影响是根本的，但海平面没有作用？o LMV是对冰川消融期间流量和泥沙负荷的高频变化做出快速反应，还是存在滞后时间？信号是向下游衰减还是传到墨西哥湾？海平面的影响是什么？它向上游延伸了多远？

GuccioneThe Lower Mississippi Valley (LMV) has the potential of understanding the linkages of upstream climate/glacial vs. downstream sea level controls of a large stream system. In addition a stratigraphic and geochronologic framework for the alluvial landforms of the valley will aid in the study of tectonic activity within the New Madrid seismic zone, within the northern valley. This proposed research seeks to develop a chronologic and genetic model for evolution of the LMV during the Late Pleistocene full glacial (late Wisconsin stage) to the earliest Holocene, a period when rapid large-scale rearrangements of the North American hydrological system occurred. These rearrangements included changes in the Laurentide ice-sheet margin, drainage of pro-glacial lakes, and se level rise. This proposal focuses on a) the role of fluctuations in discharge and sediment load from the former ice margin, b) downstream effects of sea level discharge, and c) the impact of these forcing mechanisms on landscape evolution in the LMV. We hope to address the following questions:o How do landforms and deposits of the LMV correlate to ice margin changes, floods from pro-glacial lakes, and/or specific meltwater and sediment spikes identified in the Gulf of Mexico?o How do landforms and deposits of the LMV correlate to the landforms and deposits of the upper Mississippi valley where climate/glacail impacts were fundamental, but sea level played no role?o Does the LMV respond rapidly to high-frequency changes in discharge and sediment load during deglaciation, or are there lag times? Does the signal decay downstream or is it present to the Gulf of Mexico?What is the influence of sea level and how far upstream does it extend?