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Atoll-Lagunen als Archive von Umweltveränderungen: Tsunami-Ablagerungen, Riff- und Insel-Entwicklung und Meeresspiegel in den Malediven, Indischer Ozean

Fachliche Zuordnung Paläontologie
Förderung Förderung von 2009 bis 2014
Projektkennung Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 129863134
 
Erstellungsjahr 2014

Zusammenfassung der Projektergebnisse

For the first time, the Holocene development of an atoll in the Maldives, one of the major carbonate platform regions in the world, was detailed. Pleistocene atolls were prone to karst dissolution and soil development during the last glaciation and developed saucer-shaped morphologies. During the subsequent sea-level rise, swamps formed in atoll interiors, leaving behind peat deposits. With continued rise of the sea and marginal reef growth, carbonate deposition commenced in atoll interiors. Starting in the late Holocene, sand apron progradation has significantly added to the infilling process of the lagoon, i.e., the filling of accomodation space. Apart from background sedimentation, event sedimentation tied to tsunamis may be detected in lagoonal successions of the Maldives. Confusion with storm deposits may be largely excluded as the Maldives located adjacent to the equator are virtually a storm-free region. Even though atolll lagoons evidently have a high potential as environmental recorders, the tsunami archive in atoll lagoons is presumably far from complete. The abundance of faroes, annular reefs so common to marginal reefs and lagoons in the Maldives, is largely a consequence of the changing wind and current regime in the NW Indian Ocean. By means of lateral sand/sediment transport, reefs develop sand spits that are subsequently colonized by corals. Eventually, sand spits merge and amalgamate to form faroes. The early lagoon flooding phase and the development of faroes, i.e., the formation of subbasins in atolls lagoons, may also be detected by the occurrence and biodiversity of benthic foraminifera. These organisms are major sediment producers and reach a species richness of >270 taxa in the central Maldives. Benthic foraminifera also exhibit trends of diversification and dominance as predicted by the intermediate disturbance model.

Projektbezogene Publikationen (Auswahl)

 
 

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