Modern sediments and Pleistocene reefs from isolated carbonate platforms (Iles Eparses, SW Indian Ocean): A preliminary study


Autoria(s): Jorry, Stephan; Camoin, Gilbert F.; Jouet, Gwenael; Le Roy, Pascal; Vella, Claude; Courgeon, Simon; Prat, Sophie; Fontanier, Christophe; Paumard, Victorien; Boulle, Julien; Caline, Bruno; Borgomano, Jean
Data(s)

01/04/2016

Resumo

Isolated carbonate platforms occur throughout the geologic record, from Archean to present. Although the respective roles of tectonics, sediment supply and sea-level changes in the stratigraphical architecture of these systems are relatively well constrained, the details of the nature and controls on the variability of sedimentological patterns between and within individual geomorphologic units on platforms have been barely investigated. This study aims at describing and comparing geomorphological and sedimentological features of surficial sediments and fossil reefs from three isolated carbonate platforms located in the SW Indian Ocean (Glorieuses, Juan de Nova and Europa). These carbonate platforms are relatively small and lack continuous reef margins, which have developed only on windward sides. Field observations, petrographic characterization and grain-size analyses are used to illustrate the spatial patterns of sediment accumulation on these platforms. The internal parts of both Glorieuses and Juan de Nova platforms are blanketed by sand dunes with medium to coarse sands with numerous reef pinnacles. Skeletal components including coral, green algae, and benthic foraminifera fragments prevail in these sediments. Europa platform exhibits a similar skeletal assemblage dominated by coral fragments, with the absence of wave-driven sedimentary bodies. Fossil reefs from the Last interglacial (125,000 years BP) occur on the three platforms. At Glorieuses, a succession of drowned terraces detected on seismic lines is interpreted as reflecting the last deglacial sea-level rise initiated 20,000 years ago. These findings highlight the high potential of these platforms to study past sea-level changes and the related reef response, which remain poorly documented in the SW Indian Ocean.

Formato

application/pdf

Identificador

http://archimer.ifremer.fr/doc/00292/40329/39074.pdf

DOI:10.1016/j.actao.2015.10.014

http://archimer.ifremer.fr/doc/00292/40329/

Idioma(s)

eng

Publicador

Elsevier Science Bv

Direitos

2015 Elsevier Masson SAS. All rights reserved.

info:eu-repo/semantics/openAccess

restricted use

Fonte

Acta Oecologica-international Journal Of Ecology (1146-609X) (Elsevier Science Bv), 2016-04 , Vol. 72 , P. 129-143

Palavras-Chave #Mozambique channel #Carbonate sediments #Fossil reefs #Isolated carbonate platforms
Tipo

text

Publication

info:eu-repo/semantics/article