Intensified Late Miocene Deformation in the Northern Qaidam Basin, Northern Tibetan Plateau, Constrained by Apatite Fission-Track Thermochronology

Pengju He,Yuanhao Zhao,Chunhui Song,Yihu Zhang,Yadong Wang,Wenqi Chen,Qingquan Meng

doi:10.3389/feart.2021.750993

Abstract

The Cenozoic tectonic evolution of the North Qaidam-Qilian Shan fold-thrust belt in the northern Tibetan Plateau is important to understanding the tectonic rejuvenation of orogeny and growth of the plateau. However, the deformation processes in this region remain controversial. This study presents new apatite fission track (AFT) data from Paleogene strata in the northern Qaidam Basin to investigate the time of deformation in this site. Thermal modeling of these partially annealed detrital AFT ages shows a thermal history with a noticeable transition from heating to cooling after ∼10 Ma. This transition is attributed to the intensified thrusting and folding of the northern Qaidam Basin since ∼10 Ma. Integrated with published tectonics and thermochronology results, we suggest the North Qaidam-Qilian Shan fold-thrust belt experienced prevailing tectonism since the late Miocene.

Highlights

Tibetan Plateau is an ideal region for studying the uplift of plateau and deformation of continents (Molnar et al, 1993; Yin and Harrison, 2000; Tapponnier et al, 2001; Royden et al, 2008; Wang et al, 2008; Fang et al, 2020)
This study presents new apatite fission track (AFT) data from Paleogene strata in the northern Qaidam Basin to investigate the time of deformation in this site
As the HLG section locates between the Saishiteng Shan and Luliang Shan, which is the outmost thrust belt of the North Qaidam-Qilian Shan fold-thrust belt (NQQB), we suggest tectonism transmitted to this structure belt at ∼10 model peaks ± σ (Ma) and caused persistent deformation since

Summary

Introduction

Tibetan Plateau is an ideal region for studying the uplift of plateau and deformation of continents (Molnar et al, 1993; Yin and Harrison, 2000; Tapponnier et al, 2001; Royden et al, 2008; Wang et al, 2008; Fang et al, 2020). The North Qaidam-Qilian Shan fold-thrust belt (NQQB) comprises the northern Tibetan Plateau (Figure 1), intensely deformed during the Cenozoic as a result of the remote response to Indian-Asian plate collision (Fang et al, 2005, 2007; Yin et al, 2008; Zheng et al, 2010; Zhuang et al, 2011, 2018; He et al, 2020, 2021). The evolution of Cenozoic deformation in the NQQB is crucial for understanding the growth of the Tibetan Plateau and the re-activation of ancient orogenic belts. More time records of tectonic deformation at crucial site in the NQQB is imperative

Methods

Results

Discussion

Conclusion