GRANMUD: Granulometric and geochemical contrast comparison of carbonate mud lithified under natural and laborytory conditions

GRANMUD：自然和实验室条件下岩化碳酸盐泥的粒度和地球化学对比比较

• 批准号: 92873801
• 负责人: Dr. Melanie Turpin
• 金额: --
• 依托单位: Facultad de Geología
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/92873801?language=en
• 关键词: GRANMUD; Granulometric; geochemical; contrast; comparison

Carbonate ooze, or micrite, its lithified counterpart, forms a main constituent of limestones throughout Earth History. Micrite data commonly represent a geochemical average of the depositional environmeht, but their origin (platform, slope, water column, authigenic) and mineralogy (aragonite, (Mg-)calcite) is often poorly constrained as is the geochemical and Volumetrie significance of carbonate precipitates formed during cementation. This is referred as the micrite problem . Bulk-matrix micrites form the (poorly understood) backbone of many geochemical studies dealing with past carbon cycle or chemostratigraphy. Here l propose to investigate marine carbonate oozes naturally lithified within the sediment column to variable degrees and to compare granulometric data from such micrites with such from carbonate oozes lithified under controlled laboratory conditions. The focus is both on aragonite mud (marine) as well as calcite mud (lacustrine). In the laboratory, carbonate muds are lithified using a tracer element in order to clearly separate precipitated (cement) and detrital (mud) components. The goal is to physically separate specific components of micrite and to investigate their origin, mineralogy, grain morphology and geochemistry. It is proposed to use the well established Paris method and to test the new Kiel (SPLITT) method. It is acknowledged that neither method can compensate for any post-depositional diagenetic alteration of aragonitic or high-Mg calcitic oozes but it is believed that this research is an important step in the right direction.

碳酸盐软泥，或微晶灰岩，它的石化对应物，形成了整个地球历史石灰岩的主要成分。泥晶灰岩数据通常代表沉积岩的地球化学平均值，但它们的来源（台地、斜坡、水柱、自生）和矿物学（文石、（Mg-）方解石）往往受到很差的限制，因为在胶结作用期间形成的碳酸盐沉淀物的地球化学和体积意义也是如此。这被称为微晶灰岩问题。块体基质微晶灰岩是许多地球化学研究的骨干，涉及过去的碳循环或化学地层学。在这里，我建议调查海洋碳酸盐软泥在沉积柱中自然地锂化到不同的程度，并将来自这种泥晶的粒度数据与来自在受控实验室条件下锂化的碳酸盐软泥的粒度数据进行比较。重点是文石泥（海相）和方解石泥（湖相）。在实验室中，使用示踪剂元素使碳酸盐泥浆锂化，以便清楚地分离沉淀（水泥）和碎屑（泥浆）组分。目的是物理分离泥晶灰岩的特定组分，并研究其来源、矿物学、颗粒形态和地球化学。建议使用成熟的巴黎方法并测试新的基尔（SPLITT）方法。人们承认，这两种方法都不能补偿文石或高镁方解石软泥的任何沉积后成岩蚀变，但人们认为，这项研究是朝着正确方向迈出的重要一步。