The role of currents for carbonate platform drowning

洋流对碳酸盐台地淹没的作用

• 批准号: 198293166
• 负责人: Professor Dr. Christian Betzler
• 金额: --
• 依托单位: Leitstelle Deutsche Forschungsschiffe
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/198293166?language=en
• 关键词: role; currents; carbonate; platform; drowning

The goal of this project is to test the hypothesis that the physical impact of currents is a major, previously underestimated or even disregarded controlling factor of tropical carbonate platform evolution, and that currents are a major contributor to carbonate platform drowning. It is proposed that strong and reversing currents inhibit progradation of shallow-water rubble and sands in the bank interior and therefore suppresses lateral expansion of shallow water facies. Two atolls of the Maldives archipelago, subjected to a complex regime of seasonally reversing monsoon currents, will be taken as a natural laboratory to provide data for model validation. It is thus proposed to compile a sedimentological and stratigraphical model contrasting with the established models of carbonate platforms developing in the trade-wind belts. This will be achieved by a combined approach of sidescan sonar and high-resolution seismic surveys as well as geological sampling. Dedicated transects through the lagoons will allow for establishing a stratigraphy, assessing the occurrence and the degree of lowstand karstification of the atoll interior, and mapping bedforms as an indicator of bottom currents. The new data will produce a snapshot of a carbonate platform caught in the drowning act, thus considerably expanding our knowledge about this process.

该项目的目标是检验以下假设：海流的物理影响是热带碳酸盐台地演变的一个主要的、以前被低估甚至被忽视的控制因素，海流是碳酸盐台地溺水的一个主要因素。据认为，强大的和反向电流抑制浅水碎石和砂在银行内部的渗透，从而抑制浅水相的横向扩展。马尔代夫群岛的两个环礁，受到季节性逆转季风流的复杂制度，将被视为一个自然实验室，为模型验证提供数据。因此，建议编制一个沉积学和地层学模型，与已建立的信风带碳酸盐岩台地发育模型进行对比。这将通过侧扫声纳和高分辨率地震勘测以及地质取样相结合的方法来实现。通过环礁湖的专用断面将能够建立地层学，评估环礁内部低水位岩溶作用的发生和程度，并绘制作为底流指标的底形图。新的数据将产生一个被淹没的碳酸盐岩平台的快照，从而大大扩展了我们对这一过程的了解。