Paleomagnetism of Archean Batholiths and Hadean Zircons in Australia

澳大利亚太古代岩基和太古宙锆石的古地磁学

• 批准号: 0408928
• 负责人: Benjamin Weiss
• 金额: $ 20万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0408928&HistoricalAwards=false
• 关键词: Paleomagnetism; Archean; Batholiths; Hadean; Zircons

Measurements of the evolution of the Earth's ancient magnetic field may help constrain when the field first originated, when rapid convection began in the outer core, and the time of origin of the inner core. These events in turn may have had critical implications for the evolution the planetary interior, atmosphere, and life. However, little is known about the early history of the Earth's magnetic field due to the general absence of unaltered, ancient materials. However, the investigator's preliminary work suggests that part of the Shaw Batholith and other rocks in the Pilbara craton, Western Australia likely retain magnetic records dating back to their formation from 2.2-3.5 billion years ago. These rocks may therefore contain some of the oldest known paleomagnetic records on Earth. This grant will help determine the age and nature of the magnetization in the northernmost portion of the Shaw Batholith and to establish whether it retains records of the oldest geomagnetic reversals, and (2) begin to assess the fidelity of the geomagnetic, magnetostratigraphic, and environmental magnetic records in surface and drill core samples from other areas of the Pilbara.--

地球古代磁场演变的测量值可能有助于限制当磁场首次起源，当快速对流以外核和内部核心的起源时间开始时。 这些事件反过来可能对行星内部，气氛和生命的进化产生了关键的影响。 然而，由于普遍缺乏未改变的古代材料，地球磁场的早期历史知之甚少。但是，调查员的初步工作表明，西澳大利亚州皮尔巴拉·克拉顿（Pilbara Craton）的Shaw Batholith和其他岩石的一部分可能保留了25亿年前其形成的磁记录。因此，这些岩石可能包含地球上最古老的已知古磁记录。 这笔赠款将有助于确定肖巴斯（Shaw Batholith）最北端的磁化的年龄和性质，并确定它是否保留了最古老的地磁逆转的记录，（2）开始评估地面，磁性磁性磁性的忠诚度，以及来自其他地区的表面和钻探核心样本中的磁性磁记录。