caa a22 4500 606148981 CHVBK 20210128100532.0 cr unu---uuuuu 210128e20150101xx s 000 0 eng 10.1007/s00531-014-1068-8 doi (NATIONALLICENCE)springer-10.1007/s00531-014-1068-8 Holocene sedimentary evolution of a mid-ocean atoll lagoon, Maldives, Indian Ocean [Elektronische Daten] [Lars Klostermann, Eberhard Gischler] Based on detailed analyses of cores covering the lagoon of Rasdhoo Atoll, Maldives, six carbonate facies, one soil, and one peat facies have been identified. The abundance of carbonate and rare opaque grains was quantified with a point counter. X-ray diffractometry was used to measure mineralogical composition of samples. The statistical delineation of facies using cluster analysis was based on point count, mineralogical, and textural analyses. In decreasing abundance, the six carbonate facies are classified as mollusk-coral-algal floatstone to rudstone (30%), mollusk-coral-red algae rudstone (23 %), mollusk-coral-algal wackestone to floatstone (23%), mollusk-coral wackestone (13%), mollusk-coral mudstone to wackestone (9%), and mollusk mudstone (2%). The carbonate facies represent lagoonal background sedimentation, mostly consisting of fine sediments, and event sedimentation depositing transported coarse-grained reefal components. Fifty-seven carbonate samples and one peat sample were dated radiometrically, covering the Holocene transgression from 10kyrsBP until today. Comparing the sediment accumulation data of the lagoon with two local sea-level curves, three systems tracts can be identified: (1) a lowstand systems tract characterized by karst and soil deposition >10kyrsBP, (2) a transgressive systems tract with peat and carbonate separated by hiatus 10-6.5kyrsBP, and (3) a highstand systems tract dominated by carbonate sedimentation 6.5-0kyrsBP and further divided into three stages (6.5-3, 3-1, and 1-0kyrsBP). During the Holocene transgression, sedimentation rates increased continuously to a maximum of 1.4m/kyr during 3-1kyrsBP. Modern (1-0kyrsBP) mean sedimentation rates average 0.6m/kyr. A simple calculation suggests that two processes (background sedimentation and sand apron progradation) will probably fill up the accommodation space of the lagoon during the Holocene highstand, but these processes will not suffice to fill the larger atoll lagoons of the archipelago. Springer-Verlag Berlin Heidelberg, 2014 Carbonate sediment nationallicence Sediment facies nationallicence Lagoon nationallicence Holocene nationallicence Maldives nationallicence Indian Ocean nationallicence Klostermann Lars Institut für Geowissenschaften, Goethe-Universität Frankfurt, Altenhoeferallee 1, 60438, Frankfurt am Main, Germany aut Gischler Eberhard Institut für Geowissenschaften, Goethe-Universität Frankfurt, Altenhoeferallee 1, 60438, Frankfurt am Main, Germany aut International Journal of Earth Sciences Springer Berlin Heidelberg 104/1(2015-01-01), 289-307 1437-3254 104:1<289 2015 104 531 https://doi.org/10.1007/s00531-014-1068-8 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00531-014-1068-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Klostermann Lars Institut für Geowissenschaften, Goethe-Universität Frankfurt, Altenhoeferallee 1, 60438, Frankfurt am Main, Germany aut NATIONALLICENCE 700 1- Gischler Eberhard Institut für Geowissenschaften, Goethe-Universität Frankfurt, Altenhoeferallee 1, 60438, Frankfurt am Main, Germany aut NATIONALLICENCE 773 0- International Journal of Earth Sciences Springer Berlin Heidelberg 104/1(2015-01-01), 289-307 1437-3254 104:1<289 2015 104 531