Upward and outward growth of north-central Tibet: Mechanisms that build high-elevation, low-relief plateaus.

Large orogenic plateaus, such as the Tibetan Plateau, are characterized by high-elevation, low-relief topography, in contrast to the rugged terrains of narrower mountain belts. A key question is how low-elevation hinterland basins, characteristic of broad regions of shortening, were raised while regional relief was flattened. This study uses the Hoh Xil Basin in north-central Tibet as an analogue for late-stage orogenic plateau formation.

Late Miocene Tarim desert wetting linked with eccentricity minimum and East Asian monsoon weakening.

Periodic wetting is an inherent feature of many monsoon marginal region deserts. Previous studies consistently demonstrate desert wetting during times of Earth's high orbital eccentricity and strong summer monsoon. Here we report the first evidence demonstrating desert wetting during Earth's low orbital eccentricity from the late Miocene strata of the northwestern Tarim Basin of northern China, which is commonly thought to be beyond the range of Asian monsoon precipitation.

Alpine permafrost could account for a quarter of thawed carbon based on Plio-Pleistocene paleoclimate analogue.

Estimates of the permafrost-climate feedback vary in magnitude and sign, partly because permafrost carbon stability in warmer-than-present conditions is not well constrained. Here we use a Plio-Pleistocene lacustrine reconstruction of mean annual air temperature (MAAT) from the Tibetan Plateau, the largest alpine permafrost region on the Earth, to constrain past and future changes in permafrost carbon storage. Clumped isotope-temperatures (Δ-T) indicate warmer MAAT (~1.

Pulsed rise and growth of the Tibetan Plateau to its northern margin since ca. 30 Ma.

The onset of mountain building along margins of the Tibetan Plateau provides a key constraint on the processes by which the high topography in Eurasia formed. Although progressive expansion of thickened crust underpins most models, several studies suggest that the northern extent of the plateau was established early, soon after the collision between India and Eurasia at ca. 50 Ma.

Pre-Quaternary decoupling between Asian aridification and high dust accumulation rates.

Theories of late Cenozoic climate cooling assume that central Asian aridification and high dust accumulation rates in the Chinese Loess Plateau and the North Pacific Ocean are genetically related. On the basis of detailed sediment provenance analysis, we show that high dust accumulation rates in the Chinese Loess Plateau and the North Pacific Ocean during the late Miocene-Pliocene were mainly caused by increased erosion in the Qilian Mountains and low-elevation eastern Asia areas, driven by the effects of East Asian summer monsoon intensification. We conclude that precipitation-driven erosion increased dust input to the North Pacific Ocean and may have played a pivotal role in late Cenozoic climate cooling.

Dominant 100,000-year precipitation cyclicity in a late Miocene lake from northeast Tibet.

East Asian summer monsoon (EASM) precipitation received by northern China over the past 800 thousand years (ky) is characterized by dominant 100-ky periodicity, mainly attributed to CO and Northern Hemisphere insolation-driven ice sheet forcing. We established an EASM record in the Late Miocene from lacustrine sediments in the Qaidam Basin, northern China, which appears to exhibit a dominant 100-ky periodicity similar to the EASM records during the Late Quaternary. Because evidence suggests that partial or ephemeral ice existed in the Northern Hemisphere during the Late Miocene, we attribute the 100-ky cycles to CO and Southern Hemisphere insolation-driven Antarctic ice sheet forcing.

Low palaeoelevation of the northern Lhasa terrane during late Eocene: Fossil foraminifera and stable isotope evidence from the Gerze Basin.

The Lhasa terrane is a key region for understanding the paleoelevation of the southern Tibetan Plateau after India-Asia collision. The Gerze Basin, located in the northern part of the Lhasa terrane, is a shortening-related basin. We discovered Lagena laevis (Bandy) fossils in upper Eocene strata of the Gerze Basin.

Rise of the Andes.

The surface uplift of mountain belts is generally assumed to reflect progressive shortening and crustal thickening, leading to their gradual rise. Recent studies of the Andes indicate that their elevation remained relatively stable for long periods (tens of millions of years), separated by rapid (1 to 4 million years) changes of 1.5 kilometers or more.

Rapid uplift of the Altiplano revealed through 13C-18O bonds in paleosol carbonates.

The elevation of Earth's surface is among the most difficult environmental variables to reconstruct from the geological record. Here we describe an approach to paleoaltimetry based on independent and simultaneous determinations of soil temperatures and the oxygen isotope compositions of soil waters, constrained by measurements of abundances of 13C-18O bonds in soil carbonates. We use this approach to show that the Altiplano plateau in the Bolivian Andes rose at an average rate of 1.