TY  - JOUR
A1  - Page, M.
A1  - Licht, A.
A1  - Dupont-Nivet, Guillaume
A1  - Meijer, Niels
A1  - Barbolini, Natasha
A1  - Hoorn, C.
A1  - Schauer, A.
A1  - Huntington, K.
A1  - Bajnai, D.
A1  - Fiebig, J.
A1  - Mulch, Andreas
A1  - Guo, Z.
T1  - Synchronous cooling and decline in monsoonal rainfall in northeastern Tibet during the fall into the Oligocene icehouse
JF  - Geology
N2  - The fall into the Oligocene icehouse is marked by a steady decline in global temperature with punctuated cooling at the Eocene-Oligocene transition, both of which are well documented in the marine realm. However, the chronology and mechanisms of cooling on land remain unclear. Here, we use clumped isotope thermometry on northeastern Tibetan continental carbonates to reconstruct a detailed Paleogene surface temperature record for the Asian continental interior, and correlate this to an enhanced pollen data set. Our results show two successive dramatic (>9 degrees C) temperature drops, at 37 Ma and at 33.5 Ma. These large-magnitude decreases in continental temperatures can only be explained by a combination of both regional cooling and shifts of the rainy season to cooler months, which we interpret to reflect a decline of monsoonal intensity. Our results suggest that the response of Asian surface temperatures and monsoonal rainfall to the steady decline of atmospheric CO2 and global temperature through the late Eocene was nonlinear and occurred in two steps separated by a period of climatic instability. Our results support the onset of the Antarctic Circumpolar Current coeval to the Oligocene isotope event 1 (Oi-1) glaciation at 33.5 Ma, reshaping the distribution of surface heat worldwide; however, the origin of the 37 Ma cooling event remains less clear.
Y1  - 2019
U6  - https://doi.org/10.1130/G45480.1
SN  - 0091-7613
SN  - 1943-2682
VL  - 47
IS  - 3
SP  - 203
EP  - 206
PB  - American Institute of Physics
CY  - Boulder
ER  - 
TY  - JOUR
A1  - Licht, Alexis
A1  - Dupont-Nivet, Guillaume
A1  - Pullen, A.
A1  - Kapp, P.
A1  - Abels, Hemmo A.
A1  - Lai, Z.
A1  - Guo, Z.
A1  - Abell, Jordan
A1  - Giesler, D.
T1  - Resilience of the Asian atmospheric circulation shown by Paleogene dust provenance
JF  - Nature Communications
N2  - The onset of modern central Asian atmospheric circulation is traditionally linked to the interplay of surface uplift of the Mongolian and Tibetan-Himalayan orogens, retreat of the Paratethys sea from central Asia and Cenozoic global cooling. Although the role of these players has not yet been unravelled, the vast dust deposits of central China support the presence of arid conditions and modern atmospheric pathways for the last 25 million years (Myr). Here, we present provenance data from older (42-33 Myr) dust deposits, at a time when the Tibetan Plateau was less developed, the Paratethys sea still present in central Asia and atmospheric pCO(2) much higher. Our results show that dust sources and near-surface atmospheric circulation have changed little since at least 42 Myr. Our findings indicate that the locus of central Asian high pressures and concurrent aridity is a resilient feature only modulated by mountain building, global cooling and sea retreat.
Y1  - 2016
U6  - https://doi.org/10.1038/ncomms12390
SN  - 2041-1723
VL  - 7
SP  - 885
EP  - 894
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Licht, A.
A1  - van Cappelle, M.
A1  - Abels, Hemmo A.
A1  - Ladant, J. -B.
A1  - Trabucho-Alexandre, J.
A1  - France-Lanord, C.
A1  - Donnadieu, Y.
A1  - Vandenberghe, J.
A1  - Rigaudier, T.
A1  - Lecuyer, C.
A1  - Terry, D.
A1  - Adriaens, R.
A1  - Boura, A.
A1  - Guo, Z.
A1  - Soe, Aung Naing
A1  - Quade, J.
A1  - Dupont-Nivet, Guillaume
A1  - Jaeger, J. -J.
T1  - Asian monsoons in a late Eocene greenhouse world
JF  - Nature : the international weekly journal of science
N2  - The strong present-day Asian monsoons are thought to have originated between 25 and 22 million years (Myr) ago, driven by Tibetan-Himalayan uplift. However, the existence of older Asian monsoons and their response to enhanced greenhouse conditions such as those in the Eocene period (55-34Myrago) are unknown because of the paucity of well-dated records. Here we show late Eocene climate records revealing marked monsoon-like patterns in rainfall and wind south and north of the Tibetan-Himalayan orogen. This is indicated by low oxygen isotope values with strong seasonality in gastropod shells and mammal teeth from Myanmar, and by aeolian dust deposition in northwest China. Our climate simulations support modern-like Eocene monsoonal rainfall and show that a reinforced hydrological cycle responding to enhanced greenhouse conditions counterbalanced the negative effect of lower Tibetan relief on precipitation. These strong monsoons later weakened with the global shift to icehouse conditions 34 Myr ago.
Y1  - 2014
U6  - https://doi.org/10.1038/nature13704
SN  - 0028-0836
SN  - 1476-4687
VL  - 513
IS  - 7519
SP  - 501
EP  - +
PB  - Nature Publ. Group
CY  - London
ER  -