Origin of the Dabashan Salient: Evidence from Numerical Modelling
详细信息
- 责任者：Wang Ruirui (School of Resources and Earth Sciences ; China University of Mining and Technology ; Xuzhou 221116 ; China) ; Xu Zhiqin
- 刊名：Acta Geologica Sinica
- 出版年：2013
- 卷期：87(10)
- 关键词：弧形构造 ; arcuate structure ; 大巴山 ; Daba Mountains
- 页码：p.1489-1497
- 图表：6 illus., 1 table, 39 refs.
- 分类号：0300
- issnNo：ISSN0001-5717
- isbnNo：CN11-1951/P
摘要
Dabashan salient,located in the southern margin of the Qinling orogenic belt,has attracted much attention by its remarkable bow-shaped geometry.The mechanics of the salient has long been discussed and several models have been proposed.However,these models can not account for the forming of a series of specific characteristics in the Dabashan structural belt.Recently,some researchers’ works have revealed that the maximum horizental principal stress field is radial.Using the numerical modelling method,the displacement field and stress field during intra-continental orogeny are modelled in the article.And the formation mechanism of the Dabashan salient is discussed.The numerical modelling results show that the pre-existing salient-shaped boundary originated in extensional setting and a pair of indenters in the front control the trajectory of the maximum horizontal principal stress during intra-continental orogeny.Considering the background and previous analogue modelling results by the author,décollement is also considered to be a key role in the process.The Dabashan salient resulted mainly from pre-existing salientshaped boundary formed in extensional setting,apair of indenters in the front and lower décollement.