Recent sedimentary facies of isolated carbonate platforms, Belize-Yucatan system, Central America

Abstract

Distribution of recent sedimentary facies is significantly different in four closely spaced, isolated carbonate platforms off the coasts of Belize and Yucatan (SE Mexico). These differences are largely controlled by variations in submarine topography, which are likely the result of differential subsidence and karstification from platform to platform. A variety of depositional styles and patterns is found in platform interiors that developed during the same Holocene sea-level rise. Composition and texture of surface sediment samples were used to define four major sediment types and to distinguish nine depositional environments within the platforms. Facies maps are based on analysis of 454 sediment samples and high-resolution satellite imagery. Glovers Reef is characterized by a circular facies distribution. The nearly continuous reef margin is composed of a coral-red coralline algae-Halimeda grainstone. Mixed nonskeletal (peloidal)/skeletal wackestones and packstones are present in shallow lagoon parts (Ͻ 5 m water depth) behind the margin. The deep interior, from 5 to 18 m water depth, is characterized by mollusk-foram-Halimeda wackestones with over 860 patch reefs of coral-red algae-Halimeda-mollusk packstones. Lighthouse Reef also has a coral grainstone and coral-red algae-Halimeda grainstone rim, but the facies distribution in the interior is strongly asymmetrical. The 8-m-deep eastern lagoon is floored by mollusk-foram-Halimeda wackestones and packstones; the 3-m-deep western lagoon has the mixed peloidal/skeletal wackestone to grainstone facies. A linear trend of coalescing patch reefs and skeletal grainstone facies separates the two lagoons. Banco Chinchorro is similar to Lighthouse Reef, inasmuch as facies distribution patterns of the interior are strongly asymmetrical. Mollusk-foram-Halimeda wackestones-grainstones are present in eastern lagoon areas, whereas shallow (Ͻ 5 m) western parts of the lagoon are composed of mixed peloidal/skeletal grainstones, packstones, and wackestones. Most of Turneffe Islands is protected on the east by Lighthouse Reef. Accordingly, Turneffe has a narrower reef and skeletal grainstone rim than the other two platforms. Restricted interior lagoons are up to 8 m deep, and are enclosed by wide mangrove rims and surface sediments dominated by Halimeda-rich wackestone rich in organic matter. Coral patch reefs are absent. In contrast, the unprotected northernmost part of Turneffe has a wide reef and grainstone rim and the open lagoon area consists of mollusk-foram-Halimeda wackestones-packstones with abundant patch reefs.

National assessment of shoreline change: Historical shoreline change in the Hawaiian Islands

“…Radiocarbon age of carbonate sands has been used as an indicator of longevity, production rate, and transport of coastal sediments (Kench, 1997;Gischler and Lomando, 1999). Dates measured for Hawaiian coral and skeletal fragments show that sediment is produced, transported, and lost from the coastal system on a millennial scale.…”

A Re‐Evaluation of Facies on Great Bahama Bank I: New Facies Maps of Western Great Bahama Bank

“…In a discussion of the sediment distribution of three isolated carbonate platforms seaward of the Belize barrier reef system (Glovers Reef, Lighthouse Reef and Turneffe Islands) Gischler (1994) and Gischler & Lomando (1999) suggested that variations in antecedent topography and exposure to waves and currents were the dominant factors infl uencing the sediment distribu tion of these three relatively small-scale carbonate platforms. In analogy with the scenario developed for the facies distribution of the inner lagoon of Mayotte (Zinke et al, 2001(Zinke et al, , 2003a, Gischler (2003) showed that the timing of refl ooding of the Pleistocene bedrock in combination with the rate of sea-level rise determined the sedimentation patterns in the lagoons of the Belize atolls.…”

Microfacies and depositional setting of the Upper Triassic mid-oceanic atoll-type carbonates of the Sambosan Accretionary Complex (southern Kyushu, Japan)

“…The juxtaposition of facies on the suggested profile is based on lithologies, facies interpretation, and also on comparison to depositional settings of intact time-equivalent platforms such as Dachstein Platform (Flügel 1981), Dolomites (Blendinger and Blendinger 1989), Triassic limestones of Sikhote-Alin (Punina 1997), Triassic carbonates of United Arab Emirates and Oman (Bernecker 1996;Maurer et al 2008), and modern isolated carbonate platforms such as Andros and other Islands of the Bahamas (Blatt et al 1980;Hine et al 1981), Kapingamarangi Atoll (Mckee et al 1959), Marshall Islands (Enewetak and Bikini Atolls, Atkinson et al (1981), the atoll system of the Maldives (Purdy and Bertram 1993) and the Banco Chinchorro (Gischler and Lomando 1999;Gischler and Möder 2009).…”