Determining the Cause of a Magnetic Mineral-Paleorainfall Correlation in Recent Lake Sediments

这是一个建议，调查机制，导致磁性矿物浓度和古降雨量变化之间的相关性，最近从宾夕法尼亚州东北部的湖泊沉积物。我们建议研究两个不同的小冰川湖泊，一个主要是由沉积物从外来源（Waynewood湖）和一个主要是由自生源（伊利湖）的最近的沉积物，所以降雨和矿物磁性之间的关系的一般模型可以开发。将在每个湖泊的几个地点收集冷冻岩心。将测量矿物磁性参数（c，SIRM，ARM，ARM/SIRM，SIRM/c，Hsq）以磁性表征湖泊沉积物。将进行元素分析，以确定侵蚀的重要性（Na、Mg、K）或还原成岩作用的可能性（S、Mn、Fe）。磁性提取物的电子显微镜（SEM，TEM）检查将寻找由于还原成岩作用导致的磁溶和溶解证据。EDS将用于确定是否已生成自生铁磁性铁硫化物。用FIT扫描磁力计对岩心进行高分辨率（1毫米）磁扫描，可以更详细地观察SIRM的变化，并将记录扩展到低沉积速率、沉降前的地层。

This is a proposal to investigate the mechanism causing a correlation observed between magnetic mineral concentration and paleorainfall variations in recent lake sediments from northeastern Pennsylvania. We propose to study the recent sediments from two different small glacial lakes, one dominated by sediment from allochthonous sources (Lake Waynewood) and one dominated by authigenic sources (Lake Ely), so a general model of the relationship between rainfall and mineral magnetism can be developed. Freeze cores will be collected at several locations in each lake. Mineral magnetic parameters (c, SIRM, ARM, ARM/SIRM, SIRM/c, HIRM) will be measured to magnetically characterize the lake sediments. Elemental analyses will be conducted to determine the importance of erosion (Na, Mg, K) or the possibility of reduction diagenesis (S, Mn, Fe). Electron microscopic (SEM, TEM) examination of magnetic extracts will look for magnetosotnes and evidence of dissolution due to reduction diagenesis. EDS will be used to determine if authigenic, ferromagnetic iron sulfides have been created. High resolution (1 mm) magnetic scanning of the cores with an FIT scanning magnetometer will allow a more detailed look at the SIRM variations and extension of the record into the low sedimentation rate, pre-settlement horizons.