Mapping the Internal Structure of the Chicxulub Impact Structure

绘制希克苏鲁伯撞击结构的内部结构图

• 批准号: 9908851
• 负责人: Martyn Unsworth
• 金额: $ 10.5万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-03-15 至 2003-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9908851&HistoricalAwards=false
• 关键词: Mapping; Internal; Structure; Chicxulub; Impact

Unsworth 9908851 The Chicxulub impact structure in the Yucatan Peninsula is the site of an extraterrestrial impact 65 million years ago at the end of the Cretaceous period. The structure was initially discovered using gravity and magnetic data, and has subsequently been investigated through geologic studies, drilling and geophysical exploration. It is proposed to explore the Chicxulub structure by using magnetotellurics (MT), a geophysical technique that can image subsurface electrical conductivity. This is a useful quantity to measure at Chicxulub since fractured rock has a low resistivity and re-crystallized melt has a very high resistivity. In collaboration with the Universidad Autonama de Mexico (UNAM) it is proposed to collect MT data that will (1) Locate and map the impact sheet in higher detail than has been previously possible, and (2) define the distribution of fractured basement rock to see if a correlation exists with deep whole crustal penetrating faults imaged on seismic reflection profiles. This study will increase understanding of the formation of multi-ring basins and refine estimates of how large impacts can change the global environment.

Unsworth 9908851尤卡坦半岛的希克苏鲁布撞击构造是6500万年前白垩纪末期的一次外星撞击的地点。该构造最初是利用重力和磁力数据发现的，随后通过地质研究、钻探和地球物理勘探进行了调查。提议使用大地电磁法探测希克苏鲁布构造，大地电磁法是一种能够对地下电导率成像的地球物理技术。这是在希克苏鲁布测量的一个有用的量，因为断裂岩石具有低电阻率，而再结晶熔体具有非常高的电阻率。与墨西哥自治大学（UNAM）合作，建议收集MT数据，以（1）比以前更详细地定位和绘制冲击片，（2）确定断裂基底岩石的分布，以查看是否与地震反射剖面上成像的深层全地壳穿透断层存在相关性。这项研究将增加对多环盆地形成的了解，并改进对大规模影响如何改变全球环境的估计。