Modern sediments and Pleistocene reefs from isolated carbonate platforms (Iles Eparses, SW Indian Ocean): A preliminary study
|Author(s)||Jorry Stephan1, Camoin Gilbert F.2, Jouet Gwenael1, Le Roy Pascal3, Vella Claude2, Courgeon Simon1, Prat Sophie1, Fontanier Christophe1, Paumard Victorien4, Boulle Julien1, Caline Bruno5, Borgomano Jean2, 5|
|Affiliation(s)||1 : IFREMER, Inst Carrot Edrome, Unite Geosci Marines, Lab Environm Sedimentaires, F-29280 Plouzane, France.
2 : Aix Marseille Univ, CNRS, IRD, CEREGE UM34, BP 80, F-13545 Aix En Provence, France.
3 : IUEM, Lab Domaines Ocean, F-29280 Plouzane, France.
4 : Univ Western Australia, Sch Earth & Environm, Ctr Energy Geosci, 35 Stirling Highway, Crawley, WA 6009, Australia.
5 : CSTJF, TOTAL Explorat & Prod, Ave Larribau, F-64000 Pau, France.
|Source||Acta Oecologica-international Journal Of Ecology (1146-609X) (Elsevier Science Bv), 2016-04 , Vol. 72 , P. 129-143|
|WOS© Times Cited||33|
|Note||Îles Éparses (French Scattered Islands, SW Indian Ocean) as reference ecosystems for environmental research. 2011 Iles Eparses cruise on the R/V Marion Dufresne|
|Keyword(s)||Mozambique channel, Carbonate sediments, Fossil reefs, Isolated carbonate platforms|
|Abstract||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.|