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Sea‐level and ocean‐current control on carbonate‐platform growth, M aldives, I ndian O cean
Author(s) -
Betzler Christian,
Fürstenau Jörn,
Lüdmann Thomas,
Hübscher Christian,
Lindhorst Sebastian,
Paul Andreas,
Reijmer John J. G.,
Droxler André W.
Publication year - 2013
Publication title -
basin research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.522
H-Index - 83
eISSN - 1365-2117
pISSN - 0950-091X
DOI - 10.1111/j.1365-2117.2012.00554.x
Subject(s) - progradation , geology , carbonate platform , aggradation , upwelling , sedimentary depositional environment , carbonate , paleontology , contourite , oceanography , geomorphology , chemistry , structural basin , fluvial , organic chemistry
Multichannel high‐resolution seismic and multibeam data were acquired from the M aldives‐isolated carbonate platform in the I ndian O cean for a detailed characterization of the N eogene bank architecture of this edifice. The goal of the research is to decipher the controlling factors of platform evolution, with a special emphasis on sea‐level changes and changes of the oceanic currents. The stacking pattern of L ower to M iddle M iocene depositional sequences, with an evolution of a ramp geometry to a flat‐topped platform, reflects variations of accommodation, which here are proposed to be primarily governed by fluctuations of relative sea level. Easterly currents during this stage of bank growth controlled an asymmetric east‐directed progradation of the bank edge. During the late middle M iocene, this system was replaced by a twofold configuration of bank development. Bank growth continued synchronously with partial bank demise and associated sediment‐drift deposition. This turnover is attributed to the onset and/or intensification of the Indian monsoon and related upwelling and occurrence of currents, locally changing environmental conditions and impinging upon the carbonate system. Mega spill over lobes, shaped by reversing currents, formed as large‐scale prograding complexes, which have previously been interpreted as deposits formed during a forced regression. On a regional scale, a complex carbonate‐platform growth can occur, with a coexistence of bank‐margin progradation and aggradation, as well as partial drowning. It is further shown that a downward shift of clinoforms and offlapping geometries in carbonate platforms are not necessarily indicative for a sea‐level driven forced regression. Findings are expected to be applicable to other examples of C enozoic platforms in the I ndo‐ P acific region.