scholarly journals 14C Dating of Holocene Soils from an Island in Lake Pumoyum Co (Southeastern Tibetan Plateau)

Radiocarbon ◽  
2010 ◽  
Vol 52 (3) ◽  
pp. 1443-1448 ◽  
Author(s):  
Takahiro Watanabe ◽  
Tetsuya Matsunaka ◽  
Toshio Nakamura ◽  
Mitsugu Nishimura ◽  
Takahiro Sakai ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Soil Depth ◽  
Stable Carbon Isotope ◽  
Soil Samples ◽  
14C Dating ◽  
Continuous Section ◽  
Southeastern Tibetan Plateau ◽  
Gravel Layer ◽  
Mass Spectrometry System ◽  
Pumoyum Co

Soil samples from an 85-cm-long continuous section (PY608ES) were collected from an island in Lake Pumoyum Co (southeastern Tibetan Plateau, ∼5020 m asl) in August 2006. To estimate past environmental conditions of Lake Pumoyum Co during the Holocene, we analyzed radiocarbon ages, stable carbon isotope compositions, and total organic carbon/total nitrogen (TOC/TN) atomic ratios of the soil samples. The 14C measurements were performed with the Tandetron accelerator mass spectrometry system at the Center for Chronological Research, Nagoya University. The 14C concentration in the surface layer (101 pMC; 5–10 cm soil depth) was nearly modern. A 14C chronology of the sequence indicated that continuous soil development began on the island in Lake Pumoyum Co at ∼5800 cal BP (at 63 cm soil depth, the top of a gravel layer). These results may reflect a decrease in the lake level in the middle Holocene. The age of the obvious lithologic boundary (∼5800 cal BP) corresponds to the end of Holocene climate optimum.

scholarly journals A New 14C Data Set of the PY608W-PC Sediment Core from Lake Pumoyum Co (Southeastern Tibetan Plateau) Over the Last 19 kyr

Radiocarbon ◽  
2010 ◽  
Vol 52 (3) ◽  
pp. 1435-1442 ◽  
Author(s):  
Takahiro Watanabe ◽  
Tetsuya Matsunaka ◽  
Toshio Nakamura ◽  
Mitsugu Nishimura ◽  
Yasuhiro Izutsu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Sediment Core ◽  
Environmental Changes ◽  
Plant Residue ◽  
Plant Residues ◽  
Silty Clay ◽  
Data Set ◽  
Large Plant ◽  
Southeastern Tibetan Plateau ◽  
Pumoyum Co

A new continuous sediment core (PY608W-PC; 3.8 m length) for reconstruction of climatic and environmental changes in the southeastern Tibetan Plateau was taken from the eastern part of Lake Pumoyum Co in August 2006. Sediment layers of the lower part of PY608W-PC (380–300 cm depth) were composed mainly of relatively large plant residues (up to ∼3 cm in length) with an admixture of fine sand and sandy silt. The large plant residues disappeared at ∼300–290 cm depth in core PY608W-PC and were replaced by silt-silty clay. The large plant residues from the lower part of PY608W-PC could be aquatic, because the plant residues were extremely enriched in 13C (up to –3.0‰, −5.6 ± 2.3‰ on average). On the other hand, the plant residue concentrates (PRC fractions) from the upper part of the core (290–0 cm in depth) could be terrestrial C3 plants (δ13C = –21.8 ± 1.7‰ on average). Radiocarbon dating was performed on the large plant residues and PRC fractions from the PY608W-PC sediment core, which represented the chronology from ∼19,000 cal BP to present.

Radiocarbon chronology of a sediment core from Lake Pumoyum Co in the southeastern Tibetan plateau

2008 ◽  
Vol 30 (4) ◽  
pp. 611-614 ◽  
Author(s):  
T. Watanabe ◽  
T. Nakamura ◽  
M. Nishimura ◽  
T. Matsunaka ◽  
M. Minami ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Sediment Core ◽  
Southeastern Tibetan Plateau ◽  
Radiocarbon Chronology ◽  
Pumoyum Co

scholarly journals Effect of period of sugarcane cultivation on the abundance and distribution of weed seeds in the soil profile

2014 ◽  
Vol 32 (3) ◽  
pp. 507-513
Author(s):  
R.O. Adereti ◽  
F.O Takim ◽  
Y.A. Abayomi
Keyword(s):  
Land Use ◽  
Soil Depth ◽  
Seed Banks ◽  
Soil Samples ◽  
Soil Tillage ◽  
Fallow Period ◽  
Tillage Practices ◽  
Weed Seeds ◽  
Seed Distribution ◽  
Screen House

An experiment was laid down in a screen house to determine the distribution of weed seeds at different soil depths and periods of cultivation of sugarcane in Ilorin, Nigeria. Soil samples from different depth levels (0-10 cm, 11-20 cm and 21-30 cm) were collected after harvesting of canes from three different land use fields (continuous sugarcane cultivation for > 20 years, continuous sugarcane cultivation for < 10 years after long fallow period and continuous sugarcane cultivation for < 5 years after long fallow period) in November, 2012. One kilogram of the sieved composite soil samples was arranged in the screen house and watered at alternate days. Germinating weed seedlings were identified, counted and then pulled out for the period of 8 months. Land use and soil depth had a highly significant (p £ 0.05) effect on the total number of weeds that emerged from the soil samples. The 010 cm of the soil depth had the highest weed seedlings that emerged. There was an equal weed seed distribution at the 11-20 cm and 21-30 cm depths of the soil. Sugarcane fields which have been continuously cultivated for a long period of time with highly disturbing soil tillage practices tend to have larger seed banks in deeper soil layers (11-20 cm and 21-30 cm) while recently opened fields had significantly larger seed banks at the 0-10 cm soil sampling depth.

scholarly journals Role of the Early Miocene Jinhe-Qinghe Thrust Belt in the building of the Southeastern Tibetan Plateau topography

2021 ◽  
Vol 811 ◽  
pp. 228871
Author(s):  
Chengyu Zhu ◽  
Guocan Wang ◽  
Philippe Hervé Leloup ◽  
Kai Cao ◽  
Gweltaz Mahéo ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Early Miocene ◽  
Thrust Belt ◽  
Southeastern Tibetan Plateau

scholarly journals Linking deeply-sourced volatile emissions to plateau growth dynamics in southeastern Tibetan Plateau

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Maoliang Zhang ◽  
Zhengfu Guo ◽  
Sheng Xu ◽  
Peter H. Barry ◽  
Yuji Sano ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Growth Dynamics ◽  
High Elevation ◽  
Fault System ◽  
The Tibetan Plateau ◽  
Southeastern Tibetan Plateau ◽  
Surface Uplift ◽  
Multi Stage ◽  
Geodynamic Processes ◽  
Underlying Mechanisms

AbstractThe episodic growth of high-elevation orogenic plateaux is controlled by a series of geodynamic processes. However, determining the underlying mechanisms that drive plateau growth dynamics over geological history and constraining the depths at which growth originates, remains challenging. Here we present He-CO2-N2 systematics of hydrothermal fluids that reveal the existence of a lithospheric-scale fault system in the southeastern Tibetan Plateau, whereby multi-stage plateau growth occurred in the geological past and continues to the present. He isotopes provide unambiguous evidence for the involvement of mantle-scale dynamics in lateral expansion and localized surface uplift of the Tibetan Plateau. The excellent correlation between 3He/4He values and strain rates, along the strike of Indian indentation into Asia, suggests non-uniform distribution of stresses between the plateau boundary and interior, which modulate southeastward growth of the Tibetan Plateau within the context of India-Asia convergence. Our results demonstrate that deeply-sourced volatile geochemistry can be used to constrain deep dynamic processes involved in orogenic plateau growth.

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