Paleointensity of the Earth's Magnetic Field Using Basaltic Glass

使用玄武岩玻璃测量地球磁场的古强度

• 批准号: 9205653
• 负责人: Lisa Tauxe
• 金额: $ 12.1万
• 依托单位: University of California-San Diego
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-08-15 至 1995-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9205653&HistoricalAwards=false
• 关键词: Paleointensity; Earth; Magnetic; Field; Using

The principal cause of the severe limitations of paleointensity data sets is the extreme difficulty of obtaining reliable results. Not only are the measurements time consuming, but the success rate is relatively low, despite great care in sample selection. One requires, a material possessing a thermal remanence, that has not altered since its acquisition and does not alter during the experiments. Furthermore, the material should have cooled at a rate reproducible in the laboratory, and should be datable with a relative precision of a few percent. Basaltic glass has been recovered from hundreds of Deep Sea Drilling Program holes from anomalies of known age. Glass is quenched at formation and the rate of cooling can be well approximated in the laboratory. It can be inspected for alteration and shown that it does not readily alter during the Thellier experiment. Finally, basaltic glass derived from MORB appears to contain single domain low-Ti magnetite. Shards can be found that have sufficient moments to be readily measured with our equipment; such shards obtained from 0 and 2640 year eruptions of the East Pacific Rise have yielded excellent paleointensity data and similar quality data can be obtained from other basaltic glass regardless of age. The PI will carry out a paleointensity study of basaltic glasses.

严重限制的主要原因是， 古地震强度数据集是获取的极端困难 可靠的结果。 不仅测量耗时， 但成功率相对较低，尽管非常小心， 样本选择 一个是需要一种具有热传导特性的材料， 剩磁，自其获得以来没有改变， 在实验中改变。 此外，材料应 以实验室中可重现的速率冷却，并且应 可以以百分之几的相对精度来确定日期。 玄武质 从数百个深海钻探项目中回收的玻璃 已知年代的异常现象造成的空洞 玻璃在形成时淬火 并且冷却速率可以在实验室中很好地近似。 它可以被检查的更改，并表明它没有 在Thellier实验中很容易改变。 最后，玄武岩 由MORB衍生的玻璃似乎含有单畴低Ti 磁铁矿 碎片可以被发现有足够的时刻 用我们的设备容易测量;这些碎片从0 2640年前东太平洋隆起的喷发 优秀的古强度数据和类似质量的数据， 从其他玄武岩玻璃中获得，无论年龄如何。 PI将 开展玄武岩玻璃古强度研究。