A new approach to stable isotope-based paleoaltimetry: implications for paleoaltimetry and paleohypsometry of the High Himalaya since the Late Miocene

Constraints on the early uplift history of the Tibetan Plateau

“…Thus, by using the disappearance of marine facies as a measure of early surface uplift, we conclude that the emergence of the Himalaya occurred postEocene at the earliest, possibly even more recently. Oxygen isotopebased paleoaltimetry studies from the Thakkhola graben and Gyirong basin suggest that the Tethyan Himalaya were at or near modern elevation by the mid-Miocene (14,15). Collectively, these studies are consistent with the sedimentary record of Himalayan orogenesis (46) and indicate significant southward elevation gain between 40 and Ϸ12 Ma ago.…”

“…How such high topography, which should have an effect on climate, monsoon intensity, and ocean chemistry (1)(2)(3)(4)(5), has developed through geologic time remains disputed. Various lines of investigation, including evidence from the initiation of rift basins (6), potassium-rich (K-rich) volcanism (7), tectonogeomorphic studies of fluvial systems and drainage basins (8), thermochronologic studies (9), upper-crustal deformation histories (10,11), stratigraphic and magnetostratigraphic studies of sediment accumulation rates (12), paleobotany (13), and oxygen isotope-based paleoaltimetry (14)(15)(16)(17)(18)(19)(20)(21)(22), have suggested different uplift histories. Authors of recent geologic studies (11) have proposed that significant crustal thickening (and by inference, surface uplift) in the Qiangtang terrane occurred in the Early Cretaceous [Ϸ145 mega-annum (Ma) age], followed by major crustal thickening within the Lhasa terrane between Ϸ100 and 50 Ma ago.…”

Signatures of Tibetan Plateau heating on Indian summer monsoon rainfall variability

“…One explanation for these changes is that at that time the surface of the plateau rose abruptly 1000 m or more [e.g., Harrison et al, 1992;Molnar et al, 1993], but much less than the full 5000 m present-day elevation of the plateau. Estimates of paleo-elevations of southern Tibet do not support, but rather contradict, this idea; essentially all such estimates show little change since 10 Ma to perhaps 25-35 Ma [Currie et al, 2005;DeCelles et al, 2007;Garzione et al, 2000aGarzione et al, , 2000bRowley and Currie, 2006;Rowley et al, 2001;Saylor et al, 2009;Spicer et al, 2003]. Because uncertainties in all arẽ 1000 m, however, let us consider the possibility that the average elevation of Tibet was 1000 m lower at 10-15 Ma than today.…”

Sensitivity of East Asian climate to the progressive uplift and expansion of the Tibetan Plateau under the mid-Pliocene boundary conditions

“…Some investigators speculated that significant increase in elevation of portions of the TP occurred about 7.2 Ma ago , 8 Ma ago (Harrison et al, 1992;Molnar et al, 1993;Molnar, 2005), 10 Ma ago (Rowley et al, 2001), 13.7-9 Ma ago , 11 Ma ago (Garzione et al, 2000), 12 Ma ago (Dettman et al, 2003), at least 15 Ma ago (Spicer et al, 2003), and 22 Ma ago (Guo et al, 2002). In contrast, Wang et al (1999) deduced that the TP probably reached an elevation of 1500 meters by the latest Miocene (8-5 Ma ago), not as high as was previously thought.…”