Revisiting clay‐sized mineral and elemental records of the silicate weathering history in the northern Tibetan Plateau during the late Cenozoic: The role of aeolian dust

Terra Nova ◽  
2020 ◽  
Author(s):  
Yibo Yang ◽  
Chengcheng Ye ◽  
Rongsheng Yang ◽  
Xiaomin Fang
Keyword(s):  
Tibetan Plateau ◽  
Silicate Weathering ◽  
Late Cenozoic ◽  
Aeolian Dust ◽  
Northern Tibetan Plateau

A new negative feedback mechanism for balancing Tibet uplift-driven CO2 drop: Evidence from Paleogene chemical weathering records in the northern Tibetan Plateau

2020 ◽  
Author(s):  
Xiaomin Fang ◽  
Albert Galy ◽  
Yibo Yang ◽  
Weilin Zhang ◽  
Chengcheng Ye ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Carbon Cycle ◽  
Negative Feedback ◽  
Feedback Mechanism ◽  
Global Temperature ◽  
Silicate Weathering ◽  
Negative Feedback Mechanism ◽  
Northern Tibetan Plateau ◽  
Organic Carbon Burial ◽  
Global Cooling

<p>The CO<sub>2</sub> degassing by plate tectonic process has long been thought to be balanced by weathering of silicate rocks on continents, keeping the Earth a relative stable global carbon cycle and temperature suitable for life creation, survival and evolution. The uplift of the Tibetan Plateau (TP) is hypothesized to enhance erosion and silicate weathering and organic carbon burial, thus cool the global temperature. However, the imbalance resulting from accelerated CO<sub>2</sub> consumption by uplift of the TP and a relatively stable CO<sub>2</sub> input from volcanic degassing during the Cenozoic should have depleted atmospheric CO<sub>2</sub> within a few million years; therefore, a negative feedback mechanism must have stabilised the carbon cycle. Here, we present the first almost complete Paleogene silicate weathering intensity (SWI) records from continental rocks in the northern TP, based on detailed volcanic ash and paleomagnetic dating of two continuous Cenozoic sections in the Xining and Qaidam Basin in NW China. They show that the Paleogene silicate weathering in this tectonically inactive area was modulated by global temperature. These findings suggest that Paleogene global cooling was also strongly influenced by the temperature feedback mechanism that regulated silicate weathering rates and hydrological cycles and maintained a nearly stable carbon cycle. It acted as a negative feedback through decreasing CO<sub>2</sub> consumption resulting from the lower SWI and the kinetic limitations in tectonically inactive areas that followed the global cooling. This means that the enhanced erosion and silicate weathering by the uplift of the south and central Tibetan Plateau, thus accelerated CO<sub>2</sub> consumption, must be compensated by reducing CO<sub>2</sub> consumption of the rest vast continents through their reduced silicate weathering from cooling.</p>

scholarly journals Cryoconite on a glacier on the north-eastern Tibetan plateau: light-absorbing impurities, albedo and enhanced melting

2019 ◽  
Vol 65 (252) ◽  
pp. 633-644 ◽  
Author(s):  
YANG LI ◽  
SHICHANG KANG ◽  
FANGPING YAN ◽  
JIZU CHEN ◽  
KUN WANG ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Mass Balance ◽  
Glacier Mass Balance ◽  
Eastern Tibetan Plateau ◽  
The North ◽  
Ice Surface ◽  
Northern Tibetan Plateau ◽  
North Eastern ◽  
The Mean

ABSTRACTCryoconite is a dark-coloured granular sediment that contains biological and mineralogical components, and it plays a pivotal role in geochemistry, carbon cycling and glacier mass balance. In this work, we collected cryoconite samples from Laohugou Glacier No. 12 (LHG) on the north-eastern Tibetan Plateau during the summer of 2015 and measured the spectral albedo. To explore the impacts of this sediment on surface ablation, the ice melting differences between the cryoconite-free (removed) ice and the intact layers were compared. The results showed that the mean concentrations of black carbon (BC), organic carbon (OC) and total iron (Fe) in the LHG cryoconite were 1.28, 11.18 and 39.94 mg g−1, respectively. BC was found to play a stronger role in solar light adsorption than OC and free Fe. In addition, ice covered by cryoconite exhibited the lowest mean reflectance (i.e., <0.1). Compared with the cryoconite-free ice surface, cryoconite effectively absorbed solar energy and enhanced glacial melting at a rate of 2.27–3.28 cm d−1, and free Fe, BC and OC were estimated to contribute 1.01, 0.99 and 0.76 cm d−1, respectively. This study provides important insights for understanding the role of cryoconite in the glacier mass balance of the northern Tibetan Plateau.

scholarly journals Pre-Cenozoic geologic history of the central and northern Tibetan Plateau and the role of Wilson cycles in constructing the Tethyan orogenic system

Lithosphere ◽  
2016 ◽  
Vol 8 (3) ◽  
pp. 254-292 ◽  
Author(s):  
Chen Wu ◽  
An Yin ◽  
Andrew V. Zuza ◽  
Jinyu Zhang ◽  
Wencan Liu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Geologic History ◽  
Northern Tibetan Plateau ◽  
History Of

Paleogene global cooling–induced temperature feedback on chemical weathering, as recorded in the northern Tibetan Plateau

Geology ◽  
2019 ◽  
Vol 47 (10) ◽  
pp. 992-996 ◽  
Author(s):  
Xiaomin Fang ◽  
Albert Galy ◽  
Yibo Yang ◽  
Weilin Zhang ◽  
Chengcheng Ye ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Carbon Cycle ◽  
Negative Feedback ◽  
Feedback Mechanism ◽  
Silicate Weathering ◽  
Northern Tibetan Plateau ◽  
Co2 Consumption ◽  
Temperature Feedback ◽  
Organic Carbon Burial ◽  
Global Cooling

Abstract Plate-tectonic processes have long been thought to be the major cause of the Cenozoic global carbon cycle, and global cooling by uplift of the Tibetan Plateau through enhancing silicate weathering and organic carbon burial and/or by weathering of obducted ophiolites during the closure of the Neo-Tethys Ocean. However, the imbalance resulting from accelerated CO2 consumption and a relatively stable CO2 input from volcanic degassing during the Cenozoic should have depleted atmospheric CO2 within a few million years; therefore, a negative feedback mechanism must have stabilized the carbon cycle. Here, we present the first almost-complete Paleogene silicate weathering intensity (SWI) records from continental rocks in the northern Tibetan Plateau showing that silicate weathering in this tectonically inactive area was modulated by global temperature. These findings suggest that Paleogene global cooling was also strongly influenced by a temperature feedback mechanism, which regulated silicate weathering rates and hydrological cycles and maintained a nearly stable carbon cycle. It acted as a negative feedback by decreasing CO2 consumption resulting from the lower SWI and the kinetic limitations in tectonically inactive areas.

Sign in / Sign up

Export Citation Format

Share Document