The significant role of sediment bio-retexturing within a contemporary carbonate platform system: Implications for carbonate microfacies development

Assessments of carbonate platform reef–lagoon sediments and benthic habitats around Rodrigues Island (south-west Indian Ocean) have been undertaken in order to examine carbonate sediment texturalproperties and the controls on texturally-defined sediment fabrics. Reef–lagoon sediments, sampled from a...

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Main Authors: O'Leary, Mick, Perry, C., Beavington-Penney, S., Turner, J.
Format: Journal Article
Published: Elsevier Science BV 2009
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/29158
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author O'Leary, Mick
Perry, C.
Beavington-Penney, S.
Turner, J.
author_facet O'Leary, Mick
Perry, C.
Beavington-Penney, S.
Turner, J.
author_sort O'Leary, Mick
building Curtin Institutional Repository
collection Online Access
description Assessments of carbonate platform reef–lagoon sediments and benthic habitats around Rodrigues Island (south-west Indian Ocean) have been undertaken in order to examine carbonate sediment texturalproperties and the controls on texturally-defined sediment fabrics. Reef–lagoon sediments, sampled from across the expansive (~8 km wide) carbonate-dominated windward platform, principally comprise poorly sorted medium- to coarse-grained bioclastic sands, composed of a low diversity of grain constituents — predominantly non-geniculate coralline algal bioclasts. Despite a marked homogeneity in sediment compositional and grain size properties, eight distinct sediment textural groups can be identified that form a heterogeneous mosaic across the contemporary reef–lagoon system. Only along the narrow outer platform margins (reef crest, sand apron and outermost lagoon environments) do we observe consistent (predictable) transitions in sediment textural groups, where physical processes are the primary drivers of selective sediment transport and sorting. In contrast, across the main expanse of the lagoon, the sediment substrates are characterised by an irregular mosaic of texturally-defined sediment groups — formed primarily as a function of sediment bio-retexturing. The burrowing activities of alpheid and callianassid shrimps are particularly important in this respect and impart a distinctly unique textural fabric to the upper sediment horizons in the environments in which the respective organisms occur. The consequence of this is that, at the platform system scale, individual, texturally-defined sediment groups are relatively poor indicators of prevailing hydrodynamic regimes or of local sediment production, reflecting more the biological action of organisms inhabiting the substrate. This has important implications for understanding the development of carbonate sediment fabrics in the context of palaeoenvironmental reconstructions and for interpreting a key diagnostic criteria of carbonate microfacies
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spelling curtin-20.500.11937-291582017-09-13T15:22:40Z The significant role of sediment bio-retexturing within a contemporary carbonate platform system: Implications for carbonate microfacies development O'Leary, Mick Perry, C. Beavington-Penney, S. Turner, J. Alpheid Microfacies Callianassa Bioturbation Carbonate sediments Assessments of carbonate platform reef–lagoon sediments and benthic habitats around Rodrigues Island (south-west Indian Ocean) have been undertaken in order to examine carbonate sediment texturalproperties and the controls on texturally-defined sediment fabrics. Reef–lagoon sediments, sampled from across the expansive (~8 km wide) carbonate-dominated windward platform, principally comprise poorly sorted medium- to coarse-grained bioclastic sands, composed of a low diversity of grain constituents — predominantly non-geniculate coralline algal bioclasts. Despite a marked homogeneity in sediment compositional and grain size properties, eight distinct sediment textural groups can be identified that form a heterogeneous mosaic across the contemporary reef–lagoon system. Only along the narrow outer platform margins (reef crest, sand apron and outermost lagoon environments) do we observe consistent (predictable) transitions in sediment textural groups, where physical processes are the primary drivers of selective sediment transport and sorting. In contrast, across the main expanse of the lagoon, the sediment substrates are characterised by an irregular mosaic of texturally-defined sediment groups — formed primarily as a function of sediment bio-retexturing. The burrowing activities of alpheid and callianassid shrimps are particularly important in this respect and impart a distinctly unique textural fabric to the upper sediment horizons in the environments in which the respective organisms occur. The consequence of this is that, at the platform system scale, individual, texturally-defined sediment groups are relatively poor indicators of prevailing hydrodynamic regimes or of local sediment production, reflecting more the biological action of organisms inhabiting the substrate. This has important implications for understanding the development of carbonate sediment fabrics in the context of palaeoenvironmental reconstructions and for interpreting a key diagnostic criteria of carbonate microfacies 2009 Journal Article http://hdl.handle.net/20.500.11937/29158 10.1016/j.sedgeo.2009.05.005 Elsevier Science BV restricted
spellingShingle Alpheid
Microfacies
Callianassa
Bioturbation
Carbonate sediments
O'Leary, Mick
Perry, C.
Beavington-Penney, S.
Turner, J.
The significant role of sediment bio-retexturing within a contemporary carbonate platform system: Implications for carbonate microfacies development
title The significant role of sediment bio-retexturing within a contemporary carbonate platform system: Implications for carbonate microfacies development
title_full The significant role of sediment bio-retexturing within a contemporary carbonate platform system: Implications for carbonate microfacies development
title_fullStr The significant role of sediment bio-retexturing within a contemporary carbonate platform system: Implications for carbonate microfacies development
title_full_unstemmed The significant role of sediment bio-retexturing within a contemporary carbonate platform system: Implications for carbonate microfacies development
title_short The significant role of sediment bio-retexturing within a contemporary carbonate platform system: Implications for carbonate microfacies development
title_sort significant role of sediment bio-retexturing within a contemporary carbonate platform system: implications for carbonate microfacies development
topic Alpheid
Microfacies
Callianassa
Bioturbation
Carbonate sediments
url http://hdl.handle.net/20.500.11937/29158