Cenozoic uplift of the Tibetan Plateau: Evidence from the tectonic–sedimentary evolution of the western Qaidam Basin

Abstract

Geologists agree that the collision of the Indian and Asian plates caused uplift of the Tibet Plateau. However, controversy still exists regarding the modes and mechanisms of the Tibetan Plateau uplift. Geology has recorded this uplift well in the Qaidam Basin. This paper analyzes the tectonic and sedimentary evolution of the western Qaidam Basin using sub-surface seismic and drill data. The Cenozoic intensity and history of deformation in the Qaidam Basin have been reconstructed based on the tectonic developments, faults growth index, sedimentary facies variations, and the migration of the depositional depressions. The changes in the sedimentary facies show that lakes in the western Qaidam Basin had gone from inflow to still water deposition to withdrawal. Tectonic movements controlled * Corresponding author. Tel.: þ86 10 13893297695; fax: þ86 10 09314960853.

Uplift-driven diversification in the Hengduan Mountains, a temperate biodiversity hotspot

“…We expected regional differences to reflect contrasting times of orogeny, in particular the prediction of the uplift-driven diversification hypothesis that in situ speciation increases with mountain-building activity. In this context, the late Miocene emerges as an important reference point, because previous studies of geology and paleontology indicate that the Hengduan Mountains achieved their current height only after this time, whereas the Himalayas and central QTP did so before (4,13,15,17,21). Here, our phylogenetic inferences, which make no prior assumptions about the timing of geological events, show that after about 8 Ma the rate of in situ diversification increased in the Hengduan Mountains (Fig.…”

“…One is that the central plateau was uplifted first, forming a "proto-QTP" as early as 40 Mya, with subsequent outward extensions by the early Miocene (11,14). By the late Miocene, 8 to 10 Mya, all of the mountains surrounding the QTP to the south, west, and north had reached their current elevations (12,(15)(16)(17). By contrast, uplift of the Hengduan Mountains region, at the southeastern margin (Fig.…”

Climatic and tectonic controls on sedimentation and erosion during the Pliocene-Quaternary in the Qaidam Basin (China)

“…If unit 1 is part of the Upper Youshashan Formation, then it must be time transgressive, and get younger toward our section to the northeast, where it is as young as 3.3 Ma. This interpretation, however, is inconsistent with all published ages for the Shizigou Formation that claim the formation is at least 5.2 Ma (Table S1 [see footnote 1]) and with recently published maps that place the entire study area within the Pliocene-Quaternary (fi g. 2 in Wang et al, 2012). For simplicity, we prefer to assign unit 1 to the Shizigou Formation based on age relationships, but we recognize that lateral facies changes and time-transgressive strata could result in alternative scenarios, and may imply that the Shang Youshashan Formation is much younger (ca.…”

“…Similar discrepancies are reported for the Pliocene Shizigou Formation, the basal age of which has been assigned a minimum of 5.3 Ma to a maximum 8.2 Ma, with very little discussion of potential time-transgressive behavior or facies variability (Table S1 [see footnote 1]; Y. Wang et al, 2012;Song and Wang, 1993). Overall, age as doi:10.1130/B30748.1 Geological Society of America Bulletin, published online on 22 February 2013 discrepancies for these young strata have precluded inferences about tectonic and climatic infl uences on lithofacies changes within the Qaidam Basin.…”

Late Cenozoic continuous aridification in the western Qaidam Basin: evidence from sporopollen records

“…In this case, the Qaidam Basin probably remained stable during the late Cenozoic; thus the aridification of the Qaidam Basin would have been less closely linked with the Tibetan Plateau uplift according to the models (e.g., Manabe and Terpstra, 1974;Kutzbach et al, 1989;Manabe and Broccoli, 1990;Raymo and Ruddiman, 1992;Liu et al, 2003). However, considering the several tectonic events and stratigraphic deformation history (Liu et al, 2009;Wang et al, 2012) within the basin, and the series of tectonic events on the northern Tibetan Plateau, we argue that the Qaidam Basin might have experienced upwards growth during the late Cenozoic even though an exact paleoaltimetry history cannot be established, which would have intensified aridification.…”