Geology and Hydrogeology of Mururoa and Fangataufa, French Polynesia

Buigues, D.

doi:10.1016/s0070-4571(04)80035-9

Cited by 13 publications

(7 citation statements)

References 11 publications

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“…Diagenetic loss of uranium probably shifted the date to an older age. Missing deposits of MIS 5 and 7 under Holocene atoll lagoonal deposits, however, were also reported by Buigues (1997) from, for example, Mururoa Atoll in the Pacific. Macintyre and Toscano (2004) considered the Pleistocene dates of from Belize atolls and Ambergris Cay as being "problematic and unreliable".…”

Section: Atoll and Northern Belize Datamentioning

confidence: 79%

Pleistocene facies of Belize barrier and atoll reefs

Gischler

2006

Facies

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The knowledge of Pleistocene reef facies of Belize, Central America, is largely limited to outcrops in the northernmost part of the country. Otherwise, Pleistocene limestone, which forms the basement of the modern barrier and atoll reefs, occurs in the subsurface and is to a major extent unstudied. Based on the study of 40 m of core from 25 rotary core holes collected on central and southern Belize barrier and on atoll reefs, five Pleistocene reef facies are distinguished in the present study. They include (1) Acropora palmata grainstone, (2) Acropora cervicornis grainstone, (3) biogenic grainstone, (4) mollusk packstone, and (5) mollusk-foram wackestone. Facies 1 and 3 occur on marginal reefs, facies 2 is found on marginal and lagoonal reefs, and facies 4 and 5 mark lagoon shoals and lagoons, respectively. Most of the facies have equivalents in the Pleistocene of the wider Caribbean and also in the modern of the study area. Diagenetic features include dissolution, caliche formation, laminated blocky low-magnesium-calcite and dogtooth spars. Age data from Pleistocene corals obtained during earlier studies are discussed, and indicate deposition during marine isotope stage 5, between 140-80 ka bp.

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Section: Atoll and Northern Belize Datamentioning

confidence: 79%

Pleistocene facies of Belize barrier and atoll reefs

Gischler

2006

Facies

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“…Since the above authors give no spatial dimensions of their atoll, the initial surface used in the simulation is based on the dimensions of a typical Pacific atoll, Fangataufa (Buigues, 1997). The simulated area measures 15 km by 15 km with a relief of 300 m (Fig.…”

Section: Application Of Carbonate 3d To Simulating An Offshore Atollmentioning

confidence: 99%

Quantifying the sequence stratigraphy and drowning mechanisms of atolls using a new 3‐D forward stratigraphic modelling program (CARBONATE 3D)

2002

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This paper describes a new 3‐D forward numerical model (CARBONATE 3D) that simulates the stratigraphic and sedimentological development of carbonate platforms and mixed carbonate–siliciclastic shelves by simulating the following sedimentary processes: (1) Carbonate shallow, open‐marine production, dependent on water depth, restriction and sediment input; (2) Carbonate shallow, restricted‐marine production, dependent on water restriction; (3) Pelagic sediment production and deposition; (4) Coarse and fine siliciclastic input; (5) Erosion, transport and redeposition of sediment, dependent on currents, slope, depth and restriction as well as sediment grain‐size and composition; (6) Dissolution of subaerially exposed carbonate. In this paper the model is used to investigate the controlling mechanisms on the sequence stratigraphy of isolated carbonate platforms and atolls and to predict distinctive architectural signatures from different drowning mechanisms. Investigation of the mechanisms controlling atoll strata shows that although relative sea‐level is the major control, antecedent topography, environmental setting and early diagenesis have profound influence on what stratigraphic geometries and facies develop. Hence care must be taken if sea‐level curves are interpreted from real stratigraphies. Atoll drowning by fast sea‐level rise, by lowered production and by repeated exposure and fast subsequent sea‐level rises are investigated and different stratigraphic signatures for the respective mechanisms predicted. A fast relative sea‐level rise results in a bucket‐shaped morphology developed prior to drowning and a sharp transition from the platform margin facies to a pelagic cover. Drowning caused by lowered platform margin production is predicted to result in the development of a dome‐shaped, shallow‐water shoal over the whole platform top prior to drowning. Fourth order amplitudes of several tens of metres, typical of ‘icehouse’ settings, cause atoll drowning at subsidence rates where atolls subject to fourth order amplitude of only a few metres, typical of ‘greenhouse’ settings, can keep up with the rising sea‐level. In the resultant strata, vertical facies belts are less well developed but horizontally extensive facies bands are more prominent. High fourth order amplitudes (up to 80 m) without sufficient third order scale subsidence will not lead to drowning, however, as the platform can recover in each fourth order lowstand. These results suggest that atolls might be easier to drown in ‘icehouse’ rather than in ‘greenhouse’ conditions but only in situations with suitably high rates of longer‐term relative sea‐level rise or sufficient lag times.

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“…Such a lack of knowledge is due to the difficulty of accessing the outermost and deepest parts of atoll margins. Only seaward‐oriented coring has proven to be able to access the closest parts of atoll flanks (Buigues, ; Camoin et al ., ).…”

Section: Introductionmentioning

confidence: 99%

Quaternary atoll development: New insights from the two‐dimensional stratigraphic forward modelling of Mururoa Island (Central Pacific Ocean)

et al. 2015

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Knowledge about the Quaternary evolution of mid-ocean atolls comes mainly from drilling and field observations carried out on a number of Pacific carbonate islands. However, little is known about the early to mid Pleistocene atoll development history, especially at margin and foreslope settings. Using previous field and subsurface data from Mururoa Atoll and a processbased modelling software (DIONISOS), a two-dimensional forward stratigraphic model of atoll development is proposed for the past 1Á8 million years (Myr). Observational data from vertical to inclined coring, seismic and bathymetric surveys indicate that, from approximately 0Á45 to 0Á40 million years before present (Ma), carbonate deposition at Mururoa Atoll resulted in a series of mostly prograding reef units. The model is first constrained at the base by the shape and topography of the pre-Quaternary basement. A number of sensitivity tests were performed to define the respective influence of variant parameters. The best-fit development scenario that accounts for the overall geometry and stratigraphic architecture of the Quaternary sediment packages is obtained by using the sea-level curve by Miller et al. (2005), uniform subsidence rate of 105 m Myr À1 , and carbonate production rates gradually increasing from 0Á50 to 8 mm yr À1 between 1Á80 Ma and the present. Additional controlling parameters include subaerial erosion (at a constant rate of 0Á25 m/kyr), wave-energy and sediment-transport processes. The stratigraphic forward model predicts a succession of three distinct types of carbonate systems that have developed since the earliest Pleistocene: toe of slope systems from 1Á80 Ma to about 0Á80 Ma, open-platform systems from 0Á80 Ma to 0Á50 Ma, and framework-reef systems from about 0Á50 Ma to the present. The development of these different systems is most likely to be controlled by climate and changes in sea-level cycles. During the low-amplitude 41 kyr cycle periods of the earliest Pleistocene, ambient conditions were not conducive to framework-reef growth; shallow-water carbonate sedimentation was dominantly gravity-driven, operating along the platform foreslopes only. During the Mid-Pleistocene Climate Transition, narrow, open-platform units have developed at the upper parts of the pre-Quaternary basement flanks. With the onset of the high-amplitude 100 kyr sea-level modes and climate restoration, reef frameworks started to be generated. These models from Mururoa agree with a number of previous studies suggesting that most of the true framework reefs were not initiated prior to 0Á50 Ma. Mururoa Atoll is 466 demonstrated to be a robust analogue for providing more realistic interpretations of the development history of Pacific atolls. Further modelling with three-dimensional DIONISOS could generate better predictions by taking into account hydrodynamic and transport parameters more accurately.

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Geology and Hydrogeology of Mururoa and Fangataufa, French Polynesia

Cited by 13 publications

References 11 publications

Pleistocene facies of Belize barrier and atoll reefs

Pleistocene facies of Belize barrier and atoll reefs

Quantifying the sequence stratigraphy and drowning mechanisms of atolls using a new 3‐D forward stratigraphic modelling program (CARBONATE 3D)

Quaternary atoll development: New insights from the two‐dimensional stratigraphic forward modelling of Mururoa Island (Central Pacific Ocean)

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