Premium
Pulsed growth of the West Qinling at ~30 Ma in northeastern Tibet: Evidence from Lanzhou Basin magnetostratigraphy and provenance
Author(s) -
Wang Weitao,
Zhang Peizhen,
Liu Caicai,
Zheng Dewen,
Yu Jingxing,
Zheng Wenjun,
Wang Yizhou,
Zhang Huiping,
Chen Xiuyan
Publication year - 2016
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 - 10.1002/2016jb013279
Subject(s) - geology , provenance , magnetostratigraphy , foreland basin , paleocurrent , structural basin , paleontology , plateau (mathematics) , cenozoic , cretaceous , subsidence , neogene , conglomerate , clastic rock , mathematical analysis , mathematics
The development of Cenozoic basins in the northeast margin of the Tibetan Plateau is central to understanding the dynamics of plateau growth. Here we present a magnetostratigraphy from the Lanzhou Basin, dating the terrestrial deposits from the Eocene (~47 Ma) to the middle Miocene (~15 Ma). The stratigraphic observation, palocurrent, and sediment provenance analysis suggest that the Lanzhou Basin (subbasin of the Longzhong Basin) probably initiated as a topographically enclosed depression during Eocene to early Oligocene (~47–30 Ma). We suspect that right‐lateral transtensional deformation inherited from the Cretaceous may result in formation of the Lanzhou Basin at the Eocene. Subsequently, changes in paleocurrent, sandstone and conglomerate compositions and detrital zircon provenance reflect the pulsed growth of the West Qinling at ~30 Ma, which triggered not only the formation of new flexural subsidence to the north of the West Qinling, but also renewed subsidence of Lanzhou Basin into the broad foreland basin system. We compare this growth history with major NE Tibet deformation and suggest that it may result from northeastward extrusion of the Tibetan Plateau due to the onset of Altyn Tagh Fault activity at Oligocene.