Tests of Stratigraphic Correlation & Nutrient Accumulation Hypotheses in Lake Erie and Lake Ontario

高密度岩心中生物硅浓度峰值 伊利湖和安大略湖的沉积区提供了两个 潜在的时间范围，将用于测试的限制， 沉积盆地地层对比 第一峰值 与欧洲人定居和森林砍伐有关 在20世纪80年代后期，第二个高峰被归因于一个 1950年后，污水处理人口迅速增加。 的因果 对这两个峰值假设的机制是增加输入 磷和由此产生的硅藻产量增加， 二氧化硅成为限制。 拟议的基本目标 研究的目的是确定生物硅地层学 与沉积速率有关的变化以及营养物质 积累（不同形式的磷和生物硅） 随沉积速率而变化。 这项研究具有重要的生态意义， 硅质微体化石种群结构分析， 确定是否存在时间相关信号 沉积盆地 此外，该研究将解决 关于磷负荷与 硅藻产量可能与以前报道的不同 在文学作品中。 因此，对生物硅和 硅质微体化石为独立开发 沉积物记录中的时间生物标志物， 因果机制负责他们的存在。

Peaks in biogenic silica concentration in cores from high sedimentation areas in Lake Erie and Lake Ontario provide two potential time horizons that will be used to tests the limits of stratigraphic correlation in depositional basins. The first peak has been associated with European settlement and forest clearance in the late 1980's and the second peak has been attributed to a rapid increase after 1950 in sewered population. The causal mechanism hypothesized for both peaks is increased inputs of phosphorus and resulting increased production of diatoms until silica becomes limiting. The basic objectives of the proposed research are to determine how the biogenic silica stratigraphy changes in relation to sedimentation rate and whether nutrient accumulation (different forms of phosphorus and biogenic silica) varies with sedimentation rate. This research has important ecological implication because siliceous microfossil population structure will be analyzed to determine if time-dependent signals are present across depositional basins. In addition, the research will address questions about the relationship between phosphorous loading and diatom production which may be different than reported previously in the literature. Thus, research on biogenic silica and siliceous microfossils offers promise for developing independent time biomarkers in the sediment record and in understanding the causal mechanisms responsible for their presence.