High Resolution Paleomagnetism and Magnetostratigraphy of Ferrar Volcanic rocks from the Southern Mesa Range (North Victoria Land, Antarctica)

梅萨山脉南部（南极洲北维多利亚地）费拉尔火山岩的高分辨率古地磁学和磁性地层学

基本信息

批准号：
131563479
负责人：
Professor Dr. Valerian Bachtadse
金额：
--
依托单位：
Sektion Geophysik
依托单位国家：
德国
项目类别：
Infrastructure Priority Programmes
财政年份：
2009
资助国家：
德国
起止时间：
2008-12-31 至 2013-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/131563479?language=en
关键词：
Resolution Paleomagnetism Magnetostratigraphy Ferrar Volcanic

项目摘要

Continental Flood Basalts (CFB) such as the Karoo-Ferrar province are interpreted as having been emplaced over continental areas in the order of 10 km and within a relatively short period of time of less than 1m.y. and therefore are often linked to mass extinctions. Whether the Karoo-Ferrar volcanic rocks of early Jurassic age meet the requirement of rapid extrusion has recently been debated and geochronological data suggests a longer duration of the volcanic activity of up to 6 m.y. If this longer period of emplacement is realistic than it becomes questionable whether the end- Plienbachian mass extinction is linked to the Karro-Ferrar CFB at all. Taking into account that the early Jurassic geomagnetic field displays extremely high reversal rates, any volcanic sequence which spans more than 1m.y. should record at least one, but probably more, reversals of the Earth magnetic field. It is therefore planned to study paleomagnetically the Kirkpatrick basalts of Mesa Range, Antarctica, where at least 40 volcanic flows are exposed in the Gair Mesa a sequence of up to 800m in height. Preliminary results of earlier studies suggest that there is a realistic chance to isolate primary magnetizations a notion being supported by the presence of unaltered glass in the ground mass which has been described for these rocks indicates the pristine conditions of these basalts. Our studies will be complemented by the determination of paleointensities. Taking into account that the paleointensity data base for the Mesozoic is extremely small, any contribution towards improvement of data density represents a great step forward to a better understanding geodynamo processes in the past.

大陆洪水玄武岩（CFB），例如卡鲁·费拉尔省（Karoo-Ferrar Province），被解释为已在10公里的订单上以10公里的范围内置于大陆区域，并且在相对较短的时间少于1m.y的时间内。因此，通常与大规模灭绝有关。最近对侏罗纪早期年龄的Karoo-Ferrar火山岩满足了快速挤压的要求，并且年代学数据表明，火山活动的持续时间更长，高达6M.Y。如果这种较长的时期是现实的，那么是否可以质疑终端的质量灭绝是否与karro-ferrar CFB相关。考虑到早期的侏罗纪地磁场表现出极高的逆转率，任何跨越超过1m.y的火山序列。应该记录至少一个（但可能更多）地球磁场的逆转。因此，计划在南极洲梅萨山脉的柯克帕特里克玄武岩上研究古磁，那里至少40个火山流在盖尔梅萨中暴露了高度高达800m的序列。早期研究的初步结果表明，有一个现实的机会隔离原发性磁化一个概念，即在地面质量中存在未更换的玻璃，这对这些岩石进行了描述，这表明这些底层的原始条件。我们的研究将通过确定遗传敏感性来补充。考虑到中生代的古显度数据库极小，对提高数据密度的任何贡献都代表着向前更好地理解过去的Geodynamo过程迈出的一大步。