Zoeken
Zoeken kan via de modus 'eenvoudig zoeken' (één veld) of uitgebreid via 'geavanceerd zoeken' (meerdere velden). Zo kan je bv. zoeken op een combinatie van een auteursnaam (auteur), een jaartal (jaar) en een documenttype.
Boekenmand
Nuttige resultaten kan je aanvinken en toevoegen aan een mandje. De inhoud hiervan kan je exporteren of afdrukken (naar bv. PDF).
RSS
Op de hoogte blijven van nieuw toegevoegde publicaties binnen uw interessegebied? Dit kan door een RSS-feed (?) te maken van jouw zoekopdracht.
nieuwe zoekopdracht
Controle climatique et tectonique de l'édification recifale en Nouvelle-Calédonie au cours du Quaternaire terminal
Cabioch, G.; Recy, J.; Jouannic, Ch.; Turpin, L. (1996). Controle climatique et tectonique de l'édification recifale en Nouvelle-Calédonie au cours du Quaternaire terminal. Bull. Soc. Géol. Fr. 167(6): 729-742
In: Bulletin de la Société Géologique de France. Société Géologique de France: Paris. ISSN 0037-9409; e-ISSN 1777-5817, meer
|  |
| Trefwoorden |
Colonization
Earth sciences > Geology > Sedimentology
Earth sciences > Geology > Stratigraphy
Earth sciences > Geology > Tectonics
Geological time > Phanerozoic > Geological time > Cenozoic > Quaternary > Holocene
Geological time > Phanerozoic > Geological time > Cenozoic > Quaternary > Pleistocene
New Caledonia
Reef formation
Reefs > Biogenic deposits > Coral reefs > Barrier reefs
Reefs > Biogenic deposits > Coral reefs > Fringing reefs
Temporal variations > Long-term changes > Sea level changes > Eustatic changes
New Caledonia [Marine Regions]
Marien/Kust |
| Auteurs | | Top |
- Cabioch, G.
- Recy, J.
- Jouannic, Ch.
- Turpin, L.
|
|
|
| Abstract |
Sedimentological and stratigraphic analysis of about 40 sub-surface cores drilled through the reefs of New Caledonia (especially fringing reefs) provides valuable data on the processes of reef recolonization following the last postglacial sea-level rise, and on the vertical tectonic behaviour of the island over the past 125.000 years (i.e. the late Pleistocene period). Holocene reefs in New Caledonia are not older than 8.5 ka, most probably because the sea surface temperature around the island (Lat. 19-23 degree S) was formerly too cold to allow significant reef development. This sugaests that the intertropical belt had markedly narrowed during the last glacial period, but, following the deglaciation, the southern tropical limit shifted progressively southward to include New Caledonian latitudes. The fringing reef which developed during the last interglacial high sea-level stand, 125 ka ago, is today uplifted and lies along some 30 km of coast in the area of Tara /Yate, in the SE of the island. There, it reaches a maximum elevation of 10 m, while the present-day barrier reef is deeply submerged (around -15 to -20 m). Near Hienghene (east coast), a double system of two notches is markedly deformed by a bulge, but is much more localized (3 km long) than in the Yate area, with a maximum uplift of 13 m of the upper double notch system (interpreted as having formed during the last interglacial event). Relics of the 125 ky frineing reef are emergent at various locations in the Bourail region (west coast). However, their altitudes are lower than that generally admitted (+ 6 m) for their construction at 125 ka, thus most probably reflecting a slight subsidence of the area. Elsewhere, the 125 ka fringing reef underlies the Holocene reef: in the SW of the island, in particular, the Holocene-Pleistocene unconformity is observed at - 6 m. In areas of higher subsidence rates, such as the NW or NE of the island, the 125 ka fringing reef may be more deeply buried. In that case, the Holocene reef rests directly on a metamorphic or sedimentary substratum, Within the barrier reef build-up itself, the 125 ka reef flat is overlain by a Holocene sequence, whose thickness depends on local subsidence rates. The overall setting of the 125 ka reef around New Caledonia reflects an increasing -- though irregular -- tendency for island subsidence northward and south-westward from a relatively more stable, possibly slightly uplifting, central zone, that includes the Bourail area to the west and the Yate/Tara and Hienghene areas to the east. Subsidence rates increase even more markedly seaward, as, for instance, in the Noumea lagoon or at the Yate barrier reef. The New Caledonian ridge seems to have undergone continuous warping over the past 125.000 years. This longitudinal and transversal warping is, in fact, characteristic of the vertical tectonic behaviour of the ridge since Miocene times. The observation of notches, raised beach-rocks or coral reefs (dated at around 5,500 yr) uplifted up to 1 to 1.5 m above MLWS reflects the existence of a hydro-isostatic rebound. Traces of this rebound disappear in areas of high subsidence rate, illustrating the action of local tectonics. |
IMIS is ontwikkeld en wordt gehost door het VLIZ.
