Volume 91, Issue 3 pp. 857-874
Original Articles
Full Access

Emplacement Mechanism of the Akebasitao Pluton: Implications for Regional Tectonic Evolution of West Junggar, NW China

Pan ZHANG

Pan ZHANG

Center for Global Tectonics, School of Earth Sciences, China University of Geosciences, Wuhan 430074 China

Institute of Geological Survey, China University of Geosciences, Wuhan 430074 China

Search for more papers by this author
Guocan WANG

Corresponding Author

Guocan WANG

Center for Global Tectonics, School of Earth Sciences, China University of Geosciences, Wuhan 430074 China

Institute of Geological Survey, China University of Geosciences, Wuhan 430074 China

Corresponding author. E-mail: [email protected]Search for more papers by this author
Yongtao LI

Yongtao LI

Institute of Geophysics and Geomatic, China University of Geosciences, Wuhan 430074 China

Search for more papers by this author
Shengye ZHANG

Shengye ZHANG

Institute of Geophysics and Geomatic, China University of Geosciences, Wuhan 430074 China

Search for more papers by this author
Chao PENG

Chao PENG

Center for Global Tectonics, School of Earth Sciences, China University of Geosciences, Wuhan 430074 China

Institute of Geological Survey, China University of Geosciences, Wuhan 430074 China

Search for more papers by this author
Hongwei ZHAO

Hongwei ZHAO

Center for Global Tectonics, School of Earth Sciences, China University of Geosciences, Wuhan 430074 China

Institute of Geological Survey, China University of Geosciences, Wuhan 430074 China

Search for more papers by this author
Yanhong ZHA

Yanhong ZHA

Center for Global Tectonics, School of Earth Sciences, China University of Geosciences, Wuhan 430074 China

Institute of Geological Survey, China University of Geosciences, Wuhan 430074 China

Search for more papers by this author
First published: 05 July 2017
Citations: 4

About the first author:

ZHANG Pan male; born in 1992 in Heze City, Shandong Province; Ph.D. (ABD); School of Earth Sciences, China University of Geosciences (Wuhan); His research interests are regional geotectonics and geodynamics in West Junggar Orogenic belt. Email: [email protected].

Abstract

Late Carboniferous to Early Permian A-type granites are extensively distributed throughout the West Junggar region, NW China, and the Akebasitao pluton is extremely distinguished among these plutons. In this paper, we reported new anisotropy of magnetic susceptible (AMS) data combine with detailed field study and audio magnetotelluric (AMT) sounding to assess the three-dimensional shape and magmatic emplacement mechanism of the Akebasitao pluton. The geological features and the AMT sounding indicate that the pluton had a slightly oblique movement of magma from northwest to southeast, which was most likely to correspond to an asymmetrical torch with a laccolith-shaped upper part, and a lower part formed by sub-vertical “root” that was located within its northwestern part, probably controlled by the NE-trending Anqi fault. The AMS fabrics of all the specimens reveal a low Pj value (mean of 1.02) and a low T value (mean of −0.024), suggesting that the deformation of the AMS ellipsoid is relatively weak. The specimens exhibit both oblate and prolate shapes of the AMS ellipsoid. Magnetic lineations and foliations are randomly distributed throughout the pluton without any preferred orientation. These AMS patterns indicate that the pluton formed in a relatively stable structural environment with no regional extrusion. Therefore, we propose a complex emplacement process in which the magmas reached the shallower crust levels via deep-faults and subsequently occupied the room created by doming, accompanied by stoping near the pluton roof. Additionally, the regional tectonic setting was relatively stable during the emplacement of the Akebasitao pluton, indicating the termination of compressional orogeny during the late Late Carboniferous in the West Junggar region. This conclusion perfectly coincides with the regional tectonic paleogeography, magmatic system, and paleostress field.

 

    The full text of this article hosted at iucr.org is unavailable due to technical difficulties.