Study on Restrictive Factor of Fold-Thrust Belt Formation with Multiple Decollements: Taking Eastern Sichuan-Xuefeng Tectonic Belt as an Example
详细信息
- 责任者：Liu Chongqing (State Key Laboratory of Petroleum Resource and Prospecting ; China University of Petroleum ; Beijing 102249 ; China) ; Zhou Jianxun
- 刊名：Journal of Earth Sciences and Environment
- 出版年：2013
- 卷期：35(2)
- 关键词：滑脱构造 ; decollement ; 四川 ; Sichuan Province
- 页码：p.45-55
- 图表：illus., 1 table, 43 refs.
- 分类号：0300
- issnNo：ISSN1672-6561
- isbnNo：CN61-1423/P
摘要
In order to study the impact of properties of decollement layer on the tectonic style and evolution of multiple decollements system,three sets of cross-sectional model were designed,and the impacts of rheological property and depth of decollement on the tectonic deformation of overlying strata were physically simulated,and the simulation result was contrasted with the geological condition of fold-thrust belt in the eastern Sichuan-Xuefeng tectonic belt.The results showed that the rheological properties of decollement layer affected the direction of strain adjustment of overlying strata;the strata deformation under the influence of horizontal cumulative contraction decollement layer had more horizontal components of strain,so that the stress transmitted rapidly and widely,and the wide and gentle fold-thrust belt developed;the direction of strata deformation under the influence of high rheological decollement layer was significant vertical movement,and the narrow fold-thrust belt developed with large taper angle;the depth of decollement layer controlled the wavelength of overlying strata fold,the fold with large wavelength controlled by deep decollement distributed tightly and developed as trough-likefold;high-steep anticline controlled by shallow decollement distributed sparsely and developed as partition style fold;the sedimentary cover thickness,quantity of decollement layer and decollement depth in different areas and the SE-NW-trending extrusion stress were the key factors for the development of partition style fold and trough-like fold in the eastern Sichuan-Xuefeng tectonic belt.