High-resolution Stratigraphy: Application to Hydrologic- Climatic Reconstruction in Southwestern United States

这是一个更新的研究，旨在建立一个气候参考剖面，以检验末次极冰期（~35Ka至12.5ka）之前、期间和之后发生的异常大而快速的气候变化的同步性。新墨西哥州中部水文封闭的埃斯坦西亚盆地特别适合作为参考剖面，因为它以前位于极地锋急流之下，因为它有不间断的高分辨率地层和古生物记录，因为它记录了对气候强迫的强烈、清晰和可测量的反应。丰富的介形虫和花粉可用于AMS测年。采样间隔，由于高积累率和弱生物扰动，具有小于十年的气候变化的实际分辨率。对沉积物组成、氧18和碳13以及水化学（介形虫物种丰度）的紧密间隔（~50年）分析，以及质量平衡计算和水文模型将用于在数百年至数千年的时间尺度上量化P-E。以更紧密的间隔分析与成分和其他变化有关的灰度图像，将描述年际到世纪尺度的气候变化。记录的气候变率模式包括~2000年的高水位和低水位、非常强烈的~200 ~ 250年的蒙德尺度振荡和~20年的周期。基于大量介形类的AMS测年，更精确的年龄模型和年代地层学将确定Estancia遗址在冰期极大期和同位素阶段3后期记录的异常大而快速的气候波动的时间。Estancia参考部分将是这一重要时间间隔内气候变化的第一个完整的陆基高分辨率年表。它将作为联系和解释区域气候变化以及半球和全球气候事件的基础。

This is a renewal of research to establish a climatic reference section for examining the synchroneity of the exceptionally large and rapid changes in climate that occurred before, during, and after the last glacial maximum (~35Ka to 12.5ka). The hydrologically closed Estancia basin in central New Mexico is especially well suited as a reference section because of its previous location under the Polar Front Jet Stream, because of its uninterrupted high-resolution stratigraphic and paleontologic record, and because it recorded a strong, clear, and measurable response to climate forcing. Abundant ostracodes and pollen are available for AMS dating. The sampling interval, owing to a high accumulation rate and weak bioturbation, has a practical resolution for changes in climate of less than a decade. Closely spaced (~50- yr) analyses of sediment composition, oxygen 18 and carbon 13, and hydrochemistry (ostracode species abundance), along with mass- balance calculations and a hydrologic model will be used to quantify P-E on the time scale of centuries to millennia. Gray- scale images linked to compositional and other changes analyzed at more closely spaced intervals will characterize interannual to century-scale climatic variability. Patterns of recorded climatic variability include ~2000-yr highstand and lowstands, very strong ~200-to 250-yr, Maunder-scale oscillations, and ~20-years cycles. A more accurate age model and chronostratigraphy based on AMS dating of abundant ostracodes will determine the timing of the unusually large and rapid climatic fluctuations recorded at the Estancia site during the glacial maximum and during the later part of isotope stage 3. The Estancia reference section will be the first complete, land-based high-resolution chronology for changes in climate during this important time interval. It will serve as the basis for correlating and interpreting regional shifts in climate as well as hemispheric and global climatic events.