Paleomagnetic behavior of volcanic rocks from Isla Socorro, Mexico

被引:12
作者
Sbarbori, Elise [1 ]
Tauxe, Lisa [1 ]
Goguitchaichvili, Avto [2 ]
Urrutia-Fucugauchi, Jaime [3 ]
Bohrson, Wendy A. [4 ]
机构
[1] Scripps Inst Oceanog, La Jolla, CA 92093 USA
[2] Univ Nacl Autonoma Mexico, LIMNA, Inst Geofis, Campus Morelia, Michoacan, Mexico
[3] Univ Nacl Autonoma Mexico, Inst Geofis, Lab Paleomagnetismo & Paleoambientes, Mexico City 04510, DF, Mexico
[4] Cent Washington Univ, Dept Geol Sci, Ellensburg, WA 98926 USA
来源
EARTH PLANETS AND SPACE | 2009年 / 61卷 / 01期
基金
美国国家科学基金会;
关键词
Paleomagnetism; paleointensity; Socorro; Bruhnes; IZZI method; PARTIAL THERMOREMANENT MAGNETIZATION; MULTIDOMAIN GRAINS; EASTERN PACIFIC; OCEAN ISLAND; LAVA FLOWS; GEOCHEMISTRY; FIELD; INTENSITY; PETROLOGY; HAWAII;
D O I
10.1186/BF03352899
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
The direction and magnitude of the geomagnetic field vary both spatially and temporally and undergo significant departures from that of a geocentric axial dipole. In order to properly characterize persistent behaviors, time-averaged field models must be based oil the highest quality data. Here we present full-vector paleomagnetic data for volcanic units exposed in the southeast quadrant of the island of Socorro, Mexico. We carried out a joint expedition between the Scripps Institution of Oceanography and the Universidad Nacional Autonoma Mexico to Isla Socorro in January of 2005 during which we collected oriented paleomagnetic samples from 21 sites, representing as many as 10 different volcanic units (the oldest of which is similar to 540 ka). We subjected over 100 specimens to the most up-to-date paleointensity methods, and included the standard reliability checks. In all earlier study, Bohrson et al. (1996) proposed a series of widespread eruptive events, based on similarities of argon/argon dates. Paleointensity from specimens that conform to the strictest acceptance criteria are available from both the (unoriented) original sample collection and our fully oriented (but as yet undated) new collection. Correlation between the two collections is however problematic. The time-averaged direction from Socorro is consistent with that expected from a geocentric axial dipole, and the time-averaged intensity is 30.0 +/- 7.1 mu T, equivalent to a virtual axial dipole moment (VADM) of 67.6 +/- 16.0 ZAm(2).
引用
收藏
页码:191 / 204
页数:14
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