@misc{10481/98125,
year = {2016},
month = {11},
url = {https://hdl.handle.net/10481/98125},
abstract = {Seismic, hydroacoustic and sedimentological data were used to analyse the
response of atoll-slope sedimentation in the Maldives to the late Quaternary
sea-level change. The slope deposits, as imaged in multichannel seismic profiles,
are arranged into stacked aggrading to backstepping basinward thinning
wedges. In a piston core recovered at the lower slope of one of the atolls, the
sediment texture ranges from packstone to rudstone. Major components are
blackened bioclasts, the large benthic foraminifers Operculina and Amphistegina,
together with Halimeda debris and red algae. Radiocarbon dating at a core
depth of 66 cm indicates that the wedge sedimentation stopped or was largely
reduced after 16 ka BP. Therefore, the atoll-slope deposits largely consist of
sediment formed in situ and deposited during the last glacial lowstand in sealevel.
This is in apparent contradiction to the concept of highstand shedding of
tropical carbonate platforms, which requires slope sedimentation during sealevel
highstands, when the platform is flooded. Rather than intrinsic factors,
such as sediment bypass along the steep slope, the extrinsic process of current
winnowing of the slope appears to be a major controlling factor in the production
of this feature. This process may be relevant for other case studies of carbonate
platforms, as currents may be accelerated around such edifices, leading
to slope winnowing and sediment deposition in more current-protected zones.
The study results also have consequences for the interpretation of outcrop and
seismic subsurface data of carbonate platform slope series, because such slope
sediment wedges are not necessarily formed during sea-level highstands, but
can consist of lowstand wedges only.},
organization = {03S0405, 03G0236A, German Federal Ministry of Education and Research},
organization = {Ministry of Fisheries and Agriculture of the Maldives},
publisher = {Wiley},
keywords = {Drift deposits},
keywords = {large benthic foraminifers},
keywords = {rhodoliths},
title = {Lowstand wedges in carbonate platform slopes (Quaternary, Maldives, Indian Ocean)},
doi = {10.1002/dep2.21},
author = {Betzler, Christian and Hübscher, Christian and Lindhorst, Sebastian and Lüdmann, Thomas and Reijmer, John J. G. and Braga Alarcón, Juan Carlos},
}