Controls on turbidite deposition offshore the Chilean convergent margin

对智利辐合边缘近海浊积岩沉积的控制

基本信息

批准号：
216660054
负责人：
Professorin Dr. Anne Bernhardt
金额：
--
依托单位：
Institut für Geologische Wissenschaften
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2012
资助国家：
德国
起止时间：
2011-12-31 至 2017-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/216660054?language=en
关键词：
Controls turbidite deposition offshore Chilean

项目摘要

Recurrence rates of giant subduction-zone earthquakes are still highly uncertain on centennial to millennial time scales along the rupture zone of the recent Chilean earthquake (Maule region, 2/27/2010; M=8.8), but are of utmost importance for seismic hazard prediction. Turbidite frequency has been used to reveal earthquake recurrence intervals along seismically hazardous continental margins but these results are still strongly debated. Only if the controls on turbidite deposition are well understood, the compilation of a turbidite paleoseismologic record can be successful. To establish recurring seismicity as a trigger for turbidity currents, synchronous deposition of turbidites in widely spaced, isolated depocenters has to be demonstrated. The main purpose of this study is to evaluate the relative contributions and history of controls on Holocene turbiditic sediment flux within two climatic zones along the Chilean margin. The development of a holistic model of deep-marine sedimentation focusing on terrestrial and submarine components and their interactions will allow to evaluate the feasibility of compiling a turbidite paleoseismologic record. If the Chilean margin proves to be a suitable place, such a record for two seismotectonic segments will be compiled. The proposed approach entails obtaining: (1) robust geochronologic constraints of the timing of turbidite layers, (2) correlation of turbidite ages and depositional rates to records of on- and offshore forcings, and (3) to test for coeval turbidite deposition in 7 depocenters to compile a paleoseismologic record for the Maule (34º-38ºS) and an adjacent rupture zone (30º-32ºS).

巨型俯冲区地震的复发率仍然高度不确定，沿着最近智利地质的破裂区到千禧一代的百年纪念至千年时间尺度（Maule地区，2/27/2010； M = 8.8），但对于地震危害预测至关重要。浑浊的频率已用于揭示沿地震危险连续边缘的地质复发间隔，但这些结果仍然是有力的。只有对浊度沉积的控制良好，才能成功地汇编，构曲岩古介质的记录才能成功。为了建立反复出现的地震性作为浊度电流的触发，必须证明浊积岩的同步沉积。这项研究的主要目的是评估沿智利边缘的两个气候区域内全新世浊度太阳通量的相对贡献和历史。开发着集中于陆地和海底组件的深海洋沉积模型及其相互作用，将允许评估编译浊积岩古学记录的可行性。如果智利边缘被证明是一个合适的地方，则将编译两个Seismotectonic片段的记录。提出的方法需要获得：（1）浊度层时机的强大基量限制，（2）（2）浊度年龄的相关性和与近海强迫记录的相关性以及（3）测试7个二级浊度及其在7个deporters and compuret and shosissical and seputter and seputter and sepulets and seputt and seputt and sapersistic and seputter（34）（34）（34）（30º-32º）。