Analysis of Sediment Areal Distribution in Laguna Potrok Aike (ASADO)

拉古纳波特罗克艾克 (ASADO) 沉积物面积分布分析

• 批准号: 37334882
• 负责人: Professor Dr. Bernd Zolitschka
• 金额: --
• 依托单位: Arbeitsgruppe Geomorphologie und Polarforschung
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2009-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/37334882?language=en
• 关键词: Analysis; Sediment; Areal; Distribution; Laguna

We propose to carry out a mapping of surficial sediments in Laguna Potrok Aike, southern Patagonia (Argentina). This will bring forward our understanding of processes controlling the spatial sediment distribution, geochemical sediment characteristics and nutrient availability in a modern maar lake. In view of the approaching ICDP deep drilling “Potrok Aike Maar Lake Sediment Archive Drilling Program” (PASADO) this knowledge is vital for a thorough understanding of the long sediment record to be drilled from the deep central lake basin. With the proposed mapping project five aspects of spatial sediment variability will be covered. (1) Which depositional processes are important and is it possible to distinguish particles that have experienced long eolian transport? (2) Changes in redox conditions reflected by the Fe/Mn-ratio occur in the sediment profile. Can these be used as a proxy for palaeo lake level variations? (3) Changes in phosphorus concentration probably vary with water depth. Where is the origin of the high phosphorous concentration and how do these changes influence lake biota and carbonate precipitation? (4) The validity of stable isotope values (13C) as a proxy for palaeo-shoreline proximity will be tested. (5) It will be checked whether pollen are evenly distributed across the lake and provide a comparable signal for all investigated core positions.

我们建议在巴塔哥尼亚南部（阿根廷）的拉古纳Potrok Aike进行表层沉积物制图。这将提高我们对现代玛珥湖沉积物空间分布、沉积物地球化学特征和营养盐有效性的认识。鉴于即将进行的ICDP深钻“Potrok Aike Maar湖沉积物档案钻探计划”（PASADO），这一知识对于彻底了解从中央湖深盆地钻探的长期沉积物记录至关重要。在拟议的绘图项目中，将涵盖空间沉积物变异性的五个方面。(1)哪些沉积过程是重要的，是否有可能区分经历了长期风尘搬运的颗粒？(2)铁/锰比反映的氧化还原条件的变化发生在沉积物剖面。这些可以作为古湖泊水位变化的替代物吗？(3)磷浓度的变化可能随水深而变化。高磷浓度的起源是什么？这些变化如何影响湖泊生物群和碳酸盐沉淀？(4)将测试稳定同位素值（δ 13 C）作为古海岸线接近度的替代指标的有效性。(5)将检查花粉是否均匀地分布在整个湖面上，并为所有调查的核心位置提供可比信号。