Mesozoic Intra-Continental Progressive Deformation in Western Hunan-Hubei-Eastern Sichuan Provinces of China: Evidence from Apatite Fission Track and Balanced Cross-Section
MEI Lian-fu
LIU Zhao-qian
TANG Ji-guang
SHEN Chuan-bo
FAN Yuan-fang
Abstract：The Mesozoic intra-continental evolution of about 400 km wide middle-upper Yangtze thrust belt from western Hunan-Hubei-easteru Sichuan provinces has been established with a time interval of 70 Ma (from 165 Ma to 95 Ma). Based on apatite fission track (AFT), time-temperature thermal history and balanced cross-section, we conclude that the deformation evolution is progressive from southeast (Jiangnan-Xuefeng intra-continental orogeny) to northwest (Huayingshan thrust belt),and younger and younger. The shortening of thick-skinned fault-fold zone in western Hunan Province-Hubei Province is less than that of thin-skinned fault-fold zone in east Sichuan Province. The shortening rate of the fault-fold zone in western Hunan Province-Hubei Province during Jurassic is obviously more than that of the southeast region of the fault-fold zone of eastern Sichuan Province during the early and middle periods of Early Crataceous. And the shortening rate of the southeast region of the fault-fold zone of eastern Sichuan Province during the early and middle periods of Early Crataceous is more than that of the northwest region of the fault-fold zone of eastern Sichuan Province during the late periods of Early Crataceous. The differences of the shortening rates in the different zones are controlled by the basement and the strength of the compressional deformation.These results indicate that Mesozoic intra-continental deformation in western Hunan Province-Hubei Province to eastern Sichuan Province is progressive with a large width and a long diachronous interval. Because of the different basement, basement involvement level and participation level of detachment layer, the differences of shorterning and shortening rates reflect the obvious differences of intra-continental deformation and its dynamics. The "driving engine" of Mesozoic intra-continental progressive deformation is speculated to be in Taoyuan-Huaihua area, if the Jiangnan-Xuefeng uplift is in place or parautochthon. The Taoyuan-Huaihua area is also where the Jiangnan-Xuefeng Mesozoic intra-continental orogenesis began and expanded southward and northward with a flower-structure geometry.
Keywords：western Hunan-Hubei-eastern Sichuan provincesMesozoictectonicsfission trackbalanced cross-section.
Publication Date：2010-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：14( 161-174 )