| Texto completo | |
| Autor(es): |
Duarte, L. R. C.
;
Kochhann, K. G. D.
;
Trentin, F. A.
;
Kochhann, M. V. L.
;
Leandro, L. M.
;
Oliveira, R. G.
;
D'Apolito, C.
;
Villegas-Martin, J.
Número total de Autores: 8
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Geophysical Research Letters; v. 52, n. 18, p. 12-pg., 2025-09-18. |
| Resumo | |
Carbon cycling in tropical wetlands may have significantly influenced climate variability during past phases of global warmth, such as during hyperthermal events. However, poorly resolved age models for terrestrial sections hamper correlations with global events. During the warm Middle Miocene, the megalake phase of the Pebas wetland system was active in western Amazonia. Here, we present a cyclostratigraphic analysis of hydroclimate proxies recorded by a Middle Miocene sedimentary archive retrieved from western Amazonia, spanning the intervals 14.4-14.1 Ma (Langhian) and 12.6-12.4 Ma (Serravalian). We identified orbital cycles with periods of similar to 87-133, similar to 17-19, and 11-13 kyr within the Langhian, and similar to 19-23 and 10-11 kyr within the Serravallian. This change of eccentricity-precession-semiprecession to precessional-only forcing suggests a shift toward modern-like hydroclimate variability over western Amazonia after East Antarctic Ice Sheet expansion during the Middle Miocene Climate Transition. (AU) | |
| Processo FAPESP: | 21/02877-3 - Evolução paleoceanográfica do giro subtropical do Atlântico Sul durante os últimos 800.000 anos com base em uma abordagem multi-proxy |
| Beneficiário: | Marcus Vinicius Lermen Kochhann |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado |