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.--

对地球古代磁场演化的测量可能有助于限制磁场最初起源的时间，外核快速对流开始的时间以及内核起源的时间。 这些事件反过来可能对行星内部、大气层和生命的演化产生了重要影响。 然而，由于普遍缺乏未改变的古代材料，人们对地球磁场的早期历史知之甚少。然而，研究人员的初步工作表明，西澳大利亚皮尔巴拉克拉通的部分肖氏岩和其他岩石可能保留了可追溯到22亿至35亿年前形成的磁性记录。因此，这些岩石可能包含地球上已知的最古老的古地磁记录。 这笔赠款将有助于确定肖岩最北端磁化的年龄和性质，并确定它是否保留了最古老的地磁反转记录，以及（2）开始评估皮尔巴拉其他地区地表和钻孔岩芯样本中地磁、磁性地层和环境磁性记录的保真度。