|
|
|
|
|
Wan, Sui; Jian, Zhimin. |
Deep ocean circulation is widely considered as one of the important factors for increasing CO2 concentration and decreasing radiocarbon activity (C-14) of the atmosphere during the last deglaciation. The AMS C-14 ages of benthic and planktonic foraminifers from 18 samples of Core MD05-2904 (water depth of 2066m) in the northern South China Sea (SCS) and 15 samples of Core MD05-2896 (water depth of 1657m) in the southern SCS were analyzed in this study for reconstructing the intrabasin deep oceanic processes and hence exploring the deep water exchanges between the SCS and the Pacific since the last glacial period. The results show that during the Holocene the average apparent ventilation age of deep water was younger in the southern SCS (1350years) than in... |
Tipo: Text |
Palavras-chave: Deep water renewal; AMS 14C dating; Last glacial cycle; South China Sea. |
Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00289/40040/39257.pdf |
| |
|
|
Fankhauser, Adelheid; Mcdermott, Frank; Fleitmann, Dominik. |
Eighty four new U-Th ages are presented for twenty randomly selected broken, displaced and reworked calcite speleothems retrieved from clastic sedimentary fill and from isolated bedding-plane shelves in Crag cave (SW Ireland). The dated pre-Holocene samples span much of the last glacial, ranging in age from 85.15 +/- 0.60 to 23.45 +/- 0.17 ka. Speleothem deposition requires the presence of liquid water, and because Crag cave is a shallow system, deposition is considered likely only when mean annual air temperatures (MAAT) exceed the freezing point of water. Deposition at this mid-latitude ocean-marginal site occurred episodically during MIS5a through to MIS2, synchronously within dating uncertainties, with the timing of Greenland Interstadials (GI). In the... |
Tipo: Text |
Palavras-chave: Speleothems; Last glacial cycle; Greenland Interstadials; NGRIP chronology. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00421/53211/83358.pdf |
| |
|
|
|