A 26,000-year integrated record of marine and terrestrial environmental change off Gabon, west equatorial Africa SCIE SCOPUS

Cited 14 time in WEB OF SCIENCE Cited 17 time in Scopus
Title
A 26,000-year integrated record of marine and terrestrial environmental change off Gabon, west equatorial Africa
Author(s)
Kim, So-Young; Scourse, James; Marret, Fabienne; Lim, Dhong-Il
KIOST Author(s)
Lim, Dhong Il(임동일)
Alternative Author(s)
김소영; 임동일
Publication Year
2010-11-10
Abstract
Dinoflagellate cysts, pollen and charred cuticle fragments from two sediment cores (giant piston Calypso core MD03-2708 and giant gravity Casq core MD03-2708CQ) collected off the Ogooue River mouth, Gabon (01 degrees 10.33'S-08 degrees 19.01'E, 920 m water depth) have been analysed to identify the direction and timing of marine-terrestrial environmental changes over western equatorial Africa during the last 26,000 yr. Changes in the proxy records indicate that both terrestrial and oceanic domains off Gabon were impacted synchronously by significant climate changes during the last glacial-interglacial transition and Holocene. Leading into, and during, the Last Glacial Maximum (LGM), heterotrophic dinoflagellate cysts and Ca X-ray fluorescence intensity suggest nutrient enrichment off the river mouth, while pollen records indicate expansions of open forest, savannah woodland, and the Afromontane forest in the catchment area. From the deglaciation to mid-Holocene, however, a marked decrease in Brigantedinium spp. as well as in Poaceae. Cyperaceae and Podocarpus pollen reflects a reduction in nutrient supply to the coastal ocean in parallel with a reduction in grassland, herbaceous communities and Afromontane forest within the catchment. A sharp decline or even disappearance of heterotrophic species during this period is almost contemporaneous with an appearance of Operculodinium aguinawense, reflecting enhanced river influence in the study area. A marked increase of Rhizophora (mangrove) pollen during this transition also indicates eustatic sea-level rise after the LGM which forced a major expansion of the mangrove ecosystem across the gradually submerging shelf. The combination during the late Holocene of a reoccurrence of heterotrophic dinoflagellate cysts with increased Poaceae, Cyperaceae and Podocarpus pollen indicates enhanced nutrient supply to the ocean concordant with a shift to cooler/drier conditions over the Gabon basin. This appears to be linked to a deterioration of the monsoon system induced by the low sea-surface temperatures in the tropical Atlantic Ocean in association with decreased summer insolation. (C) 2010 Elsevier B.V. All rights reserved.
ISSN
0031-0182
URI
https://sciwatch.kiost.ac.kr/handle/2020.kiost/4013
DOI
10.1016/j.palaeo.2010.08.026
Bibliographic Citation
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY, v.297, no.2, pp.428 - 438, 2010
Publisher
ELSEVIER SCIENCE BV
Subject
WALLED DINOFLAGELLATE CYSTS; LAST DEGLACIATION; LATE QUATERNARY; CLIMATE CHANGES; RAIN-FOREST; TROPICAL ATLANTIC; LATE-HOLOCENE; SEDIMENTS; POLLEN; BP
Keywords
Ogooue; Monsoon; Last Glacial Maximum; Holocene; Pollen; Dinoflagellate cysts
Type
Article
Language
English
Document Type
Article
Publisher
ELSEVIER SCIENCE BV
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