Detrital Zircon Fission-Track Thermochronology of the Present-Day River Drainage System in the Mt. Kailas Area, Western
- PDF / 3,490,105 Bytes
- 9 Pages / 595.22 x 842 pts (A4) Page_size
- 96 Downloads / 138 Views
ISSN 1674-487X
Detrital Zircon Fission-Track Thermochronology of the Present-Day River Drainage System in the Mt. Kailas Area, Western Tibet: Implications for Multiple Cooling Stages of the Gangdese Magmatic Arc Tianyi Shen *, Guocan Wang School of Earth Sciences, Center for Global Tectonics, and State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074, China Tianyi Shen: https://orcid.org/0000-0002-8199-2819 ABSTRACT: It is still controversial how the high elevation of the Tibetan Plateau established after the Indian-Asian collision during the Cenozoic. The timing of Gangdese magmatic arc exhumation and uplift history would provide useful message for this disputation. We present six zircon fission-track (ZFT) data from modern river sand in the Western Tibet, around the Mt. Kailas, to decipher the long-term exhumation histories of the Gangdese magmatic arc. The data suggests that all the Gangdese magmatic arc rocks experienced rapid cooling during the Eocene (~46–35 Ma) and Oligocene (~31–26 Ma). The movement along the north-south trending extensional fault and dextral strike-slip Karakoram fault induced the adjacent rocks exhumed at the Middle Miocene (~15–16 Ma) and Late Miocene (~10–11 Ma), respectively. According to the minimum and central AFT ages for each sample, the fastest exhumation rate is about 0.4 km/Myr, with average long-term exhumation rates on the order of ~0.3 km/Myr since the Oligocene. This result supports the outward growth model for plateau forming, indicating the southern margin of the Gangdese magmatic arc attained high elevation after the Oligocene. KEY WORDS: detrital zircon fission-track, exhumation history, Gangdese magmatic arc, Western Tibet. 0
INTRODUCTION The exhumation process of the Gangdese magmatic arc, southern Tibet, is indispensable for understanding the uplift processes of the Tibetan Plateau, and has been widely discussed for many years (Ge et al., 2017; Li et al., 2016, 2015; Tremblay et al., 2015; Carrapa et al., 2014; Dai et al., 2013; Rohrmann et al., 2012; Copeland et al., 1995). During these years, many studies have suggested that the Tibetan Plateau rose and expanded from Central Tibet since the Eocene (e.g., Wang et al., 2014, 2008; Tapponnier, 2011). Many low temperature thermochronological data in the hinterland of the plateau supported this hypothesis (e.g., Haider et al., 2013; Rohrmann et al., 2012; Hetzel et al., 2011). Most of previous thermochronological studies revealed that the Gangdese batholith in the Southern Tibet mainly experienced rapidly cooling during the Miocene (e.g., Li et al., 2015; Tremblay et al., 2015; Carrapa et al., 2014), consistent with the outward growth model. However, several other studies also reported the batholith had been rapid cooled during the Early Cenozoic periods with limited data (Ge et al., 2017; Li et al., *Corresponding author: [email protected] © China University of Geosciences (Wuhan) and Springer-Verlag GmbH Germany, Part of Springer Nature 2020 Manuscript received
Data Loading...
