干旱区生态环境知识资源中心(Arid): Ultra-Low Geomagnetic Field Intensity in the Mesoproterozoic Based on the Dike Complex Rocks of the Bunger Oasis (1133 Ma, East Antarctica)

Arid

DOI	10.1134/S106935132206012X
	Ultra-Low Geomagnetic Field Intensity in the Mesoproterozoic Based on the Dike Complex Rocks of the Bunger Oasis (1133 Ma, East Antarctica)
	Shcherbakova, V. V.; Vodovozov, V. Yu.; Zhidkov, G. V.; Aphinogenova, N. A.; Sal'naya, N. V.; Leichenkov, G. L.
通讯作者	Shcherbakova, VV
来源期刊	IZVESTIYA-PHYSICS OF THE SOLID EARTH
ISSN	1069-3513
EISSN	1555-6506
出版年	2022
卷号	58 期号:6 页码:859-881
英文摘要	In order to determine the paleointensity of the geomagnetic field in the Precambrian, a collection of rocks from 83 samples of 19 sites selected from the Mesoproterozoic (1133 Ma) dikes of the Bunger Oasis (East Antarctica) was studied. The magnetic and thermomagnetic properties of rocks have been studied in details, the domain structure of magnetic grains, carriers of natural remanent magnetization, has been evaluated, and micromagnetic and X-ray studies have been carried out. It is shown that the carriers of the characteristic component of natural remanent magnetization are single- and/or small pseudo-single-domain grains. Paleointensity was determined by the Thellier-Coe method with the check-points procedure and, in addition to it, the express Wilson method. For 11 sites, low to extremely low values of paleointensity B-anc were obtained, which meet modern reliability criteria, the main array of B-anc determinations by sites is grouped around (1.5-5) mu T. The calculated values of the virtual dipole moment VDM vary from 3 to 8 (x10(21) Am-2), which is an order of magnitude (and more) less than the current VDM value. Such low values of paleointensity do not agree with the hypothesis of an increased intensity of the geomagnetic field in the Middle Proterozoic and testify against the hypothesis of the formation of the Earth's inner core in the time interval from 1.5 to 1 Ga ago. An analysis of the VDM values presented in 2022 in the world database over the interval of 3600-500 Ma showed that the behavior of the geomagnetic field in the Precambrian is characterized by the alternation of long periods of low and high intensity with a tendency to its gradual weakening from the Archean to the Neoproterozoic. A linear approximation of such a dependence of the VDM value on time has a correlation coefficient of 0.22 at a confidence level of 0.98. The noted features of the behavior of the intensity of the geomagnetic field in the Proterozoic and Paleozoic testify in favor of the hypothesis of the origin of the Earth's solid core not earlier than the Late Neoproterozoic.
英文关键词	low paleointensity Precambrian origin of the Earth's solid core Thellier method data reliability Bunger Oasis Antarctica
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000899229700005
WOS关键词	KEY PALEOMAGNETIC POLE ; EARTHS MAGNETIC-FIELD ; PALEOINTENSITY DETERMINATION ; INNER-CORE ; BASALT SAMPLES ; GA ; GABBRO ; HILLS ; GEODYNAMO ; PROVINCE
WOS类目	Geochemistry & Geophysics
WOS研究方向	Geochemistry & Geophysics
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/393251
推荐引用方式 GB/T 7714	Shcherbakova, V. V.,Vodovozov, V. Yu.,Zhidkov, G. V.,et al. Ultra-Low Geomagnetic Field Intensity in the Mesoproterozoic Based on the Dike Complex Rocks of the Bunger Oasis (1133 Ma, East Antarctica)[J],2022,58(6):859-881.
APA	Shcherbakova, V. V.,Vodovozov, V. Yu.,Zhidkov, G. V.,Aphinogenova, N. A.,Sal'naya, N. V.,&Leichenkov, G. L..(2022).Ultra-Low Geomagnetic Field Intensity in the Mesoproterozoic Based on the Dike Complex Rocks of the Bunger Oasis (1133 Ma, East Antarctica).IZVESTIYA-PHYSICS OF THE SOLID EARTH,58(6),859-881.
MLA	Shcherbakova, V. V.,et al."Ultra-Low Geomagnetic Field Intensity in the Mesoproterozoic Based on the Dike Complex Rocks of the Bunger Oasis (1133 Ma, East Antarctica)".IZVESTIYA-PHYSICS OF THE SOLID EARTH 58.6(2022):859-881.