Premium
Eocene to Miocene Out‐of‐Sequence Deformation in the Eastern Tibetan Plateau: Insights From Shortening Structures in the Sichuan Basin
Author(s) -
Tian Yuntao,
Kohn Barry P.,
Qiu Nansheng,
Yuan Yusong,
Hu Shengbiao,
Gleadow Andrew J. W.,
Zhang Peizhen
Publication year - 2018
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.983
H-Index - 232
eISSN - 2169-9356
pISSN - 2169-9313
DOI - 10.1002/2017jb015049
Subject(s) - geology , plateau (mathematics) , foreland basin , cenozoic , paleontology , outcrop , structural basin , late miocene , tectonics , paleogene , thermochronology , tectonic phase , tectonic uplift , geomorphology , mathematical analysis , mathematics
A distinctive NNE trending belt of shortening structures dominates the topography and deformation of the eastern Sichuan Basin, ~300 km east of the Tibetan Plateau. Debate continues as to whether the structures resulted from Cenozoic eastward growth of the Tibetan Plateau. A low‐temperature thermochronology (AFT and AHe) data set from four deep boreholes and adjacent outcrops intersecting a branch of the shortening structures indicates distinctive differential cooling at ~35–28 Ma across the structure, where stratigraphy has been offset vertically by ~0.8–1.3 km. This result forms the first quantitative evidence for the existence of a late Eocene‐Oligocene phase of shortening in the eastern Sichuan Basin, synchronous with the early phase of eastward growth and extrusion of the Tibetan Plateau. Further, a compilation of regional Cenozoic structures reveals a Miocene retreat of deformation from the foreland basin to the hinterland areas. Such a tectonic reorganization indicates that Eocene to Miocene deformation in the eastern Tibetan Plateau is out‐of‐sequence and was probably triggered by enhanced erosion in the eastern Tibetan Plateau.