Preliminary paleomagnetic results of the Early-Middle Silurian rocks from North Qiangtang Terrane, and its tectonic implications 羌北地块早-中志留世古地磁学初步研究结果及其构造意义

Jiang，Nan1; Wu，Hanning1; Li，Yuyu1; Wei，Bitian1; Zhou，Yanan1; Zhang，Weijie1,2; Gao，Yang1,3; Yu，Liang1,4; Wu，Jiakun1,5; Huo，Feifei1,6; Liu，Yuchun1; Wang，Baofeng1; Cheng，Xin1

2022-03-10

10.6038/cjg2022P0065

CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION   影响因子和分区

0001-5733

In order to reconstruct the Early-Middle Silurian paleogeographic position of the North Qiangtang Terrane (NQT) and to further discuss its origin, we present preliminary paleomagnetic data (10 sites, 125 samples) from the Early-Middle Silurian Longmu Co Formation sedimentary rocks at the Longmu Co area (34.4°N, 80.3°E) of the NQT. Petrography and rock magnetism reveals that magnetite is the dominant magnetic carrier in limestone samples from the Longmu Co Formation. Systematic thermal and alternating field demagnetization curves show a feature of single or two components, while the direction of the single component is consistent with that of the high-temperate/field component that decays toward the origin stably. This stable characteristic remanent magnetization (ChRM) passes the C-class reversal test at the sample level. The tilt-corrected mean direction for the Early-Middle Silurian rocks from the NQT is D=321.8°, I=41.7°, k=31.1, α=10.1°, N=8, which yields a corresponding paleomagnetic pole at -55.3°N, 163.3°E (dp/dm=7.6°/12.4°). This paleopole does not resemble to younger paleopoles from the NQT, indicating that the ChRM is very likely to be the primary remanence. Our results, together with the evidence of geology, imply that the NQT was located in the low latitudes of the Southern Hemisphere (24.0°S) during the Early-Middle Silurian times, in which, the NQT may be closely related to the South China Block and located in the paleo-ocean on the northern side of the India Plate of Gondwana.

Early-Middle Silurian North Qiangtang Terrane Paleomagnetic pole Paleomagnetism Reversal test

SCI ; EI

中文

其他

Geochemistry & Geophysics

Geochemistry & Geophysics

WOS:000769779800020

SCIENCE PRESS

20221211811587

C (programming language) ; Cobalt ; Demagnetization ; Geomagnetism ; Magnetite ; Magnetization reversal ; Remanence ; Sedimentary rocks

Earth Magnetism and Terrestrial Electricity:481.3.2 ; Minerals:482.2 ; Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals:549.3 ; Magnetism: Basic Concepts and Phenomena:701.2 ; Computer Programming Languages:723.1.1 ; Inorganic Compounds:804.2

GEOSCIENCES

2-s2.0-85126455047

Scopus

1.Department of Geology/State Key Laboratory of Continental Dynamics,Northwest University,Xi'an,710069,China
2.Department of Ocean Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China
3.Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing,100081,China
4.Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing,100101,China
5.College of Earth and Environmental Sciences,Lanzhou University,Lanzhou,730000,China
6.Zunyi Normal University,Zunyi,563006,China

Jiang，Nan,Wu，Hanning,Li，Yuyu,等. Preliminary paleomagnetic results of the Early-Middle Silurian rocks from North Qiangtang Terrane, and its tectonic implications 羌北地块早-中志留世古地磁学初步研究结果及其构造意义[J]. CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,2022,65(3):1057-1070.

Jiang，Nan.,Wu，Hanning.,Li，Yuyu.,Wei，Bitian.,Zhou，Yanan.,...&Cheng，Xin.(2022).Preliminary paleomagnetic results of the Early-Middle Silurian rocks from North Qiangtang Terrane, and its tectonic implications 羌北地块早-中志留世古地磁学初步研究结果及其构造意义.CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,65(3),1057-1070.

Jiang，Nan,et al."Preliminary paleomagnetic results of the Early-Middle Silurian rocks from North Qiangtang Terrane, and its tectonic implications 羌北地块早-中志留世古地磁学初步研究结果及其构造意义".CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION 65.3(2022):1057-1070.