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Yamamoto, Yasuto; Ajioka, Taku; Yamamoto, Masanobu. |
We investigated branched and isoprenoid glycerol dialkyl glycerol tetraethers (GDGTs) in surface soils and a paleosol sequence to understand the effects of environmental and postdepositional factors on branched GDGT composition in different soil types and to reconstruct the past changes in the mean annual air temperature (MAAT) in southwestern Japan during the last 15 ka. The estimated MAAT was overestimated by 6 degrees C and 2 degrees C when the global and regional soil calibrations were applied, respectively. Additionally, the estimated MAAT increased downward by a maximum of 4 degrees C in the upper 30 cm of the soil sequence. This is likely to reflect the addition of newly produced branched GDGTs in subsurface soils. The estimated MAATs in a paleosol... |
Tipo: Text |
Palavras-chave: GDGT; MBT/CBT; Paleotemperature; Japan; Holocene. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00421/53259/54690.pdf |
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Shiau, Liang-jian; Yu, Pai-sen; Wei, Kuo-yen; Yamamoto, Masanobu; Lee, Teh-quei; Yu, Ein-fen; Fang, Tien-hsi; Chen, Min-te. |
Variations in sea surface temperature (SST), productivity, and biogenic components such as total organic carbon (TOC), carbonate, and opal contents measured from IMAGES (International Marine Global Changes Study) core MD972142 provide information about long-term paleoceanographic changes during the past similar to 870000 years in the southeastern South China Sea (SCS). MD972142 U-37(k)-SSTs varied from 25 to 29 degrees C, paralleling the glacial to interglacial changes. MD972142 biogenic components show relatively high carbonate and opal, and low TOC contents in interglacial stages, and low carbonate and opal and high TOC contents in glacial stages, and these variations appear to be sensitive to regional terrestrial sediment input and productivity. Our... |
Tipo: Text |
Palavras-chave: Total organic carbon; Carbonate; Opal; Productivity; Sea surface temperature; South China Sea; Monsoon; IMAGES. |
Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00237/34817/33682.pdf |
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