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Chinese Science Bulletin

, Volume 57, Issue 16, pp 1982–1989 | Cite as

Magma flow inferred from magnetic fabrics in Wanning gabbro pluton and diabase dykes, Hainan

  • XiaoQing Pan
  • ZhongYue ShenEmail author
  • ChuanWan Dong
  • HanLin Chen
  • XiaoGan Cheng
  • ShuFeng Yang
  • ZhiLiang Zhang
Open Access
Article Geophysics

Abstract

Measurements of anisotropy of magnetic susceptibility (AMS) were performed on a gabbro pluton and 7 diabase dykes in the Wanning area, southeast Hainan Island. Rock magnetism showed that pseudo-single domain (PSD) to multidomain (MD) Ti-poor magnetite carries the magnetic fabric in the gabbro pluton whereas MD Ti-poor magnetite carries the magnetic fabric in the diabase dykes. The corrected anisotropy degree (P j ) in most specimens was found to be less than 1.2 which is indicative of a possible flow-related magnetic fabric. The AMS eigenvectors within each site are generally well grouped. The maximum susceptibility axes (K 1) of the gabbro pluton are inclined towards the north at low angles (< 30°). K 1 axes of the diabase dykes are inclined towards the NNW and SSE with dip angles of ⩽ 30°. From this study, it appears that the emplacement mode of the gabbro pluton was characterized by intrusion from the north to the south at a low angle whereas the diabase dykes were emplaced from the NNW to the SSE at low to moderate angles. This was verified by comparison of the rock fabric to the magnetic fabric. All of this evidence leads to the conclusion that the Wanning gabbro pluton and diabase dykes were the products of pulsative intrusion from the same magma chamber in the area far to the north of Wanning, which suggests that basic rocks may exist beneath the Indosinian granite in the area to the north of Wanning.

Keywords

Hainan AMS emplacement mode basic pluton basic dyke 

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Copyright information

© The Author(s) 2012

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 2.0 International License (https://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Authors and Affiliations

  • XiaoQing Pan
    • 1
  • ZhongYue Shen
    • 1
    Email author
  • ChuanWan Dong
    • 1
  • HanLin Chen
    • 1
  • XiaoGan Cheng
    • 1
  • ShuFeng Yang
    • 1
  • ZhiLiang Zhang
    • 1
  1. 1.Department of Earth SciencesZhejiang UniversityHangzhouChina

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