INTENSITY OF THE EARTHS MAGNETIC-FIELD SINCE PRECAMBRIAN FROM THELLIER-TYPE PALEOINTENSITY DATA AND INFERENCES ON THE THERMAL HISTORY OF THE CORE

被引：41

作者：

PREVOT, M ^{[1
]}

PERRIN, M ^{[1
]}

机构：

[1] UNIV MONTPELLIER 2,F-34095 MONTPELLIER 05,FRANCE

来源：

GEOPHYSICAL JOURNAL INTERNATIONAL | 1992年 / 108卷 / 02期

关键词：

CORE; CORE MANTLE BOUNDARY; GEODYNAMO; GEOMAGNETIC FIELD; PALEOMAGNETISM;

D O I：

10.1111/j.1365-246X.1992.tb04640.x

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

We present a compilation of palaeointensity data obtained by the Thellier method from magmatic rocks up to 3.5 Gyr old. No apparent very long-term variation occurs from present to Early Precambrian. The overall data are compatible with a gravitationally powered dynamo model in which the inner core is some 4.0 Gyr old. However, palaeointensity data are still too incomplete to dismiss the possibility of a more complex field history with a geodynamo first thermally driven then gravitationally powered. Despite the limited number of data currently available, large differences in the dipole field moment are clearly documented with a time-scale of the order of 50-100 Myr. The changes in intensity can be due to repetitive instabilities of the thermal boundary layer at the base of the mantle.

引用

页码：613 / 620

页数：8

共 59 条

[1]

Bergh H.W., 1970, PALEOGEOPHYSICS, P143

[2] REVISED AND SYNTHETIC APPARENT POLAR WANDER PATHS OF THE AFRICAN, EURASIAN, NORTH-AMERICAN AND INDIAN PLATES, AND TRUE POLAR WANDER SINCE 200 MA [J].