Full Vector Studies of the Pringle Falls Excursion Recorded at Pringle Falls, Oregon

俄勒冈州普林格尔瀑布记录的普林格尔瀑布游览的完整矢量研究

• 批准号: 1215070
• 负责人: Emilio Herrero-Bervera
• 金额: $ 10.82万
• 依托单位: University of Hawaii
• 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: 2012-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1215070&HistoricalAwards=false
• 关键词: Full; Vector; Studies; Pringle; Falls

The main objective of this proposal is to investigate the relative paleointensity of the lake sediments that recorded the Pringle Falls excursion (ca. 218+/-1o ka) at the original site of Pringle Falls along the Deschutes River in Oregon. Paleomagnetic directions (i.e. Declination and Inclination) as well as the relative paleointensity (i.e. Full Vector) from the Pringle Falls sediments will provide information on the spatial and temporal variability of the Earth's geomagnetic field for the well documented aborted reversal at Pringle Falls which duration is of few hundred years. Due to the fact that there is a real need to obtain detailed records from high-resolution sediments (i.e. high sedimentation rates, at least 10cm/year) in order to have a better understanding of the generation of the field, we propose to study in detail five sections sampled along the Deschutes River with the main objective of understanding the directional behavior as well as the geomagnetic field strength (i.e. relative paleointensity of the sections) recorded before during and after the Pringle Falls excursion in Oregon.The objectives of this proposed study are primarily related to the knowledge of the paleofield variations during periods like reversals and excursions, and the critical time intervals that precede and follow the high resolution (i.e. at least 10 cm/year of sedimentation rates) Pringle Falls excursion (recorded in Oregon) that so far have only been documented from a few sedimentary sequences particularly between 30 to 220 thousand years of the geomagnetic history. Reversal and excursion studies cannot be separated from the surrounding polarity intervals and most records published so far were not long enough to provide complete information. The lacustrine sediments along the Deschutes River sections offer the first exceptional opportunity to document field changes over a time period thatincludes a polarity episode that lasted a few hundred to, at most, several thousand years, and thus document the field behavior over various time constants. The results of the rock magnetic tests/experiments performed on pilot samples indicate that the sediments in question are suitable for the relative paleointensity studies proposed here. The magnetic results of this proposed research will contribute to the understanding of the structure in the core of the Earth, the core-mantle and the inner and outer core boundaries as well as the related causes of the generation of the Earth's magnetic field.

这一建议的主要目的是调查记录了俄勒冈州德舒特河沿岸普林格尔瀑布原址的普林格尔瀑布漂移(约218+/-10ka)的湖泊沉积物的相对古强度。来自普林格尔瀑布沉积物的古地磁方向(即偏角和倾角)以及相对古地磁强度(即全矢量)将为普林格尔瀑布持续数百年的地球磁场逆转提供有关地球磁场时空变异性的信息。由于确实需要从高分辨率沉积物(即高沉积速率，至少10厘米/年)中获得详细的记录，以便更好地了解磁场的产生，我们建议详细研究德舒特河沿岸的五个断面，主要目的是了解俄勒冈州普林格尔瀑布漂移之前、期间和之后记录的方向行为和地磁场强度(即断面的相对古磁场强度)。这项研究的目的主要是关于诸如反转和漂移等时期的古磁场变化的知识。以及在高分辨率(即至少10厘米/年的沉积速率)普林格尔瀑布漂移(在俄勒冈州记录)之前和之后的关键时间间隔，到目前为止，这些漂移只从几个沉积序列中被记录下来，特别是在地磁历史的3万到22万年之间。反转和漂移研究不能脱离周围的极性间隔，到目前为止发表的大多数记录都不足以提供完整的信息。德舒特河沿岸的湖泊沉积物提供了第一次难得的机会来记录一段时间内的场变化，其中包括持续数百年至至多数千年的极性插曲，从而记录各种时间常数上的场行为。对先导样品进行的岩石磁学测试/实验结果表明，这些沉积物适合于本文提出的相对古强度研究。这项拟议研究的磁学结果将有助于理解地核、核-地幔、核内外边界的结构以及地球磁场产生的相关原因。