|
|
|
|
|
| Railsback, L. Bruce; Brook, George A.; Liang, Fuyuan; Marais, Eugene; Cheng, Hai; Edwards, R. Lawrence. |
| Stalagmite Orum-1 from a cave near Orumana in northwestern Namibia provides a multi-proxy record of regional drying with increasing global-scale warmth over the last 47 kyr, in a region with few long well-dated location specific paleoclimate records. Data from Stalagmite Orum-1 include carbon and oxygen stable isotope ratios, proportions of aragonite and calcite, pronouncedly differing petrographic fabrics, positions of layer-bounding surfaces, variation in layer-specific width, and changes in layer thickness, all of which combine to support change from wetter to drier conditions. Combined with fourteen U-Th ages, they suggest that climate was wetter in northwestern Namibia during globally cold MIS 3 than it is today, and with more grass than is present... |
| Tipo: Text |
Palavras-chave: Namibia; Paleoclimate; Pleistocene; Holocene; Savanna; Stalagmite. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00421/53213/54862.pdf |
| |
|
|
| WATANABE,SHIGUEO; CANO,NILO F.; RAO,T.K. GUNDU; SILVA-CARRERA,BETZABEL N.; CARMO,LUCAS S.; QUINA,ANTONIO J.A.; GENNARI,ROSELI F.; MUNITA,CASIMIRO S.; AYALA-ARENAS,JORGE S.; FERNANDES,BRUNO G.. |
| ABSTRACT A cylindrical fragment of stalagmite from Caverna do Diabo, State of São Paulo, Brazil, has been studied and dated by thermoluminescence and electron paramagnetic resonance techniques. The thermoluminescence glow curves of stalagmite samples and subsequently gamma irradiated, have shown rise of three peaks at 135, 180 and 265 °C. From electron paramagnetic resonance spectra of stalagmite was possible to clearly identify three paramagnetic centers in the g = 2.0 region: Centers I, II and III are due to , and , respectively. The additive method was applied to calculate the accumulated dose using thermoluminescence peak at 265 °C and the electron paramagnetic resonance signal at g = 1.9973 of CO- 2 radical. The ages of the different slices of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Stalagmite; Caverna do Diabo; Dating; TL; EPR. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652016000602137 |
| |
|
|
|
