|
|
|
|
|
| Dolven, Jk; Cortese, G; Bjorklund, Kr. |
| Polycystine radiolarians are used to reconstruct summer sea surface temperatures (SSSTs) for the Late Pleistocene-Holocene (600-13,400 C-14 years BP) in the Norwegian Sea. At 13,200 C-14 years BP, the SSST was close to the average Holocene SSST (similar to12degreesC). It then gradually dropped to 7.1degreesC in the Younger Dryas. Near the Younger Dryas-Holocene transition (similar to10,000 C-14 years BP), the SSST increased 5degreesC in about 530 years. Four abrupt cooling events, with temperature drops of up to 2.1degreesC, are recognized during the Holocene: at 9340, 7100 ("8200 calendar years event''), 6400 and 1650 C-14 years BP. Radiolarian SSSTs and the isotopic signal from the GISP2 ice core are strongly coupled, stressing the importance of the... |
| Tipo: Text |
Palavras-chave: Radiolarians; Paleoclimate; Late Pleistocene-Holocene; Norwegian Sea. |
| Ano: 2002 |
URL: https://archimer.ifremer.fr/doc/00223/33384/31894.pdf |
| |
|
|
| Feitosa,Yuri Oliveira; Absy,Maria Lúcia; Latrubesse,Edgardo Manuel; Stevaux,José Cândido. |
| The present study reconstructs the paleovegetation of a varzea (seasonally flooded) forest in the central parts of the Madeira River floodplain in Brazil using palynological data. Forty-nine cut-bank sediment samples from the Madeira River were processed in the study; from these, ten samples contained pollen: two contained pollen from the Middle Pleniglacial age, one contained pollen from the Tardiglacial age, six contained pollen from the Holocene, and one contained more recently deposited pollen. The Middle Pleniglacial pollen belonged to a primary succession varzea forest, while the Tardiglacial pollen represented a late succession varzea forest. On the other hand, the three Holocene samples showed the characteristic composition of chavascal... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cut-bank sediment; Late Pleistocene-Holocene; Palynology; Southern Amazonian tributary; Varzea. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062015000100120 |
| |
|
| |
|
|
| ROSSETTI,DILCE F.; MOULATLET,GABRIEL M.; TUOMISTO,HANNA; GRIBEL,ROGÉRIO; TOLEDO,PETER M.; VALERIANO,MÁRCIO M.; RUOKOLAINEN,KALLE; COHEN,MARCELO C.L.; CORDEIRO,CARLOS L.O.; RENNÓ,CAMILO D.; COELHO,LUIZ S.; FERREIRA,CARLOS A.C.. |
| Abstract: What controls the formation of patchy substrates of white sand vegetation in the Amazonian lowlands is still unclear. This research integrated the geological history and plant inventories of a white sand vegetation patch confined to one large fan-shaped sandy substrate of northern Amazonia, which is related to a megafan environment. We examined floristic patterns to determine whether abundant species are more often generalists than the rarer one, by comparing the megafan environments and older basement rocks. We also investigated the pattern of species accumulation as a function of increasing sampling effort. All plant groups recorded a high proportion of generalist species on the megafan sediments compared to older basement rocks. The vegetation... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazonian wetlands; Geological history; Late Pleistocene-Holocene; Megafan sedimentary dynamics; White sand vegetation. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000700503 |
| |
|
|
|
