Microbialite development patterns in the last deglacial reefs from Tahiti (French Polynesia, IODP Expedition #310); implications on reef framework architecture

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doi: 10.1016/j.margeo.2010.10.013
Author(s): Seard, Claire; Camoin, Gilbert; Yokoyama, Yusuke; Matsuzaki, Hiroyuki; Durand, Nicolas; Bard, Edouard; Sepulcre, Sophie; Deschamps, Pierre
Author Affiliation(s): Primary:
Gentre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement, Aix-en-Provence, France
Other:
University of Tokyo, Japan
Volume Title: Marine Geology
Source: Marine Geology, 279(1-4), p.63-86. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0025-3227 CODEN: MAGEA6
Note: In English. 83 refs.; illus., incl. 5 tables, sketch map
Summary: The widespread occurrence of microbialites in the last deglacial reef frameworks (16-6KaBP) implies that the accurate study of their development patterns is of prime importance to unravel the evolution of reef architecture through time and to reconstruct the reef response to sea-level variations and environmental changes. The present study is based on the sedimentological and chronological analysis (14C AMS dating) of drill cores obtained during the IODP Expedition #310 "Tahiti Sea Level" on the successive terraces which typify the modern reef slopes from Tahiti. It provides a comprehensive data base to investigate the microbialite growth patterns (i.e. growth rates and habitats), to analyze their roles in reef frameworks and to reconstruct the evolution of the reef framework architecture during sea-level rise. The last deglacial reefs from Tahiti are composed of two distinctive biological communities: (1) the coralgal communities including seven assemblages characterized by various growth forms (branching, robust branching, massive, tabular and encrusting) that form the initial frameworks and (2) the microbial communities developed in the primary cavities of those frameworks, a few meters (1.5 to 6m) below the living coral reef surface, where they heavily encrusted the coralgal assemblages to form microbialite crusts. The dating results demonstrate the occurrence of two distinctive generations of microbialites: the "reefal microbialites" which developed a few hundred years after coralgal communities in shallow-water environments, whereas the "slope microbialites" grew a few thousands of years later in significantly deeper water conditions after the demise of coralgal communities. The development of microbialites was controlled by the volume and the shape of the primary cavities of the initial reef frameworks determined by the morphology and the packing of coral colonies. The most widespread microbialite development occurred in frameworks dominated by branching, thin encrusting, tabular and robust branching coral colonies which built loose and open frameworks typified by a high porosity (> 50%). In contrast, their growth was minimal in compact coral frameworks formed by massive and thick encrusting corals where primary cavities yielded a low porosity (∼30%) and could not host a significant microbialite expansion. Abstract Copyright (2011) Elsevier, B.V.
Year of Publication: 2011
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 06 Petrology, Sedimentary; Absolute age; Anthozoa; Assemblages; Biostratigraphy; Boreholes; C-14; Carbon; Carbonate rocks; Cenozoic; Chemostratigraphy; Chronostratigraphy; Cnidaria; Cores; Dates; East Pacific; Expedition 310; French Polynesia; Holocene; Integrated Ocean Drilling Program; Invertebrata; Isotopes; Limestone; Lithostratigraphy; Microbialite; Mineral composition; Oceania; Organic compounds; Pacific Ocean; Paleoecology; Pleistocene; Polynesia; Quaternary; Radioactive isotopes; Reefs; Sedimentary rocks; Society Islands; South Pacific; Southeast Pacific; Tahiti; Tahiti Sea Level Expedition; Total organic carbon; Upper Pleistocene; X-ray diffraction data
Coordinates: S180000 S170000 W1490000 W1500000
Record ID: 2011026382
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands