EAGER: Investigating the Thermal Maturity of Organic Matter in Fault Zones with Laboratory Experiments

EAGER：通过实验室实验研究断层带有机质的热成熟度

• 批准号: 1219488
• 负责人: Heather Savage
• 金额: $ 8.06万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1219488&HistoricalAwards=false
• 关键词: EAGER; Investigating; Thermal; Maturity; Organic

One of the most elusive questions in the study of fault mechanics is how much shearstress faults sustain, which is a necessary parameter for a full description of the ruptureprocess. Because frictional slip generates heat, measuring the temperature increase offault zones above background temperatures can elucidates the strength of the fault. Herewe describe a new paleothermometer that can establish time-temperature histories forfaults hosted in sedimentary rocks by examining the thermal maturity of organicmolecules within the fault. This technique is widely applied in petroleum geochemistryto determine burial heating. The investigators will establish a new paleothermometer for fault zones byrepurposing an existing paleothermometer used to establish long duration heatingassociated with burial. Quantifying the frictional heating in a fault zone will allow them toconstrain fault and earthquake parameters like shear stress along a fault during failure andslip of the largest event. In order to extend the time-temperature range of thispaleothermometer and establish thermal maturity indices at the short time scales and high temperatures that fault rocks experience during earthquakes, the investigators will design and conduct rapid heating experiments on organic-rich sedimentary rocks at various combinations of time and temperature relevant to seismic heating and determine the kinetic parameters of these reactions at short time scales.Measurement of the coseismic friction is critical for determining the conditions under which an earthquake can expand into a major, societally significant event. This work will devise a new way to directly measure friction from slip on faults.Furthermore, two early career scientists will be funded.

断层力学研究中最难以捉摸的问题之一是断层能承受多少剪应力，这是完整描述破裂过程的必要参数。由于摩擦滑动会产生热量，因此测量断层区域高于背景温度的温度增量可以阐明断层的强度。在这里，我们描述了一种新的古温度计，它可以通过检查断层内有机分子的热成熟度来建立沉积岩中断层的时间-温度历史。该技术广泛应用于石油地球化学领域以确定埋藏加热。研究人员将通过重新利用现有的用于建立与埋藏相关的长时间加热的古温度计，为断层带建立一个新的古温度计。量化断层带中的摩擦热将使他们能够限制断层和地震参数，例如在最大事件的破坏和滑动期间沿断层的剪切应力。为了扩大该古温度计的时间温度范围，并建立断层岩在地震过程中经历的短时间尺度和高温下的热成熟度指数，研究人员将在不同的组合下对富含有机质沉积岩进行快速加热实验。与地震加热相关的时间和温度，并确定这些反应在短时间尺度上的动力学参数。同震摩擦的测量对于确定地震扩展为重大社会重大事件的条件至关重要。这项工作将设计一种直接测量断层滑动摩擦力的新方法。此外，两名早期职业科学家将获得资助。