Late Pleistocene-Holocene acceleration of uplift rate in southwest Erromango Island, Southern Vanuatu, South Pacific: relation to the growth of the Vanuatuan Mid Sedimentary Basin
Late Quaternary and Holocene raised coral reefs are well developed in southwestern Erromango Island, which lies in the frontal arc area of the Vanuatuan Island Arc. Eight uranium series ages and one /sup 14/C age from samples from coral reefs at three localities range in age from 4800 B.P. to about 320,000 B.P. Six of the samples dated are from the Matiwo Point area. Here the youngest reef has given a /sup 230/Th//sup 234/U age of 4800 B.P. and a slightly older reef, 4.3 m higher in elevation, has a /sup 14/C age of 5270 B.P. Inland of a cliff the youngest three of four northeastward-tilted raised reefs have given /sup 230/Th//sup 234/U ages ranging from 104,000 B.P. to about 320,000 B.P. These data indicate accelerating uplift rates for southwest Erromango: during the periods 320,000-133,000 B.P., 133,000-6000 B.P., and 6000 - 0 B.P. average uplift rates were 0.33 mm/yr, 0.65 mm/yr, and about 1 mm/yr respectively. These data are interpreted to indicate the growth of the Mid Sedimentary Basin, which lies within the frontal and volcanic arc part of the island arc complex. This increase in uplift/eastward-tilting could represent a Quaternary-Late Pleistocene increase in the subduction rate of the Australian Plate beneath Erromango.
- Research Organization:
- Univ. of New South Wales, Kensington (Australia)
- OSTI ID:
- 7036330
- Journal Information:
- J. Geol.; (United States), Journal Name: J. Geol.; (United States) Vol. 96:4; ISSN JGEOA
- Country of Publication:
- United States
- Language:
- English
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Uranium-234 anomalies in corals older than 150,000 years
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Related Subjects
580100* -- Geology & Hydrology-- (-1989)
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
AGE ESTIMATION
ALPHA DECAY RADIOISOTOPES
AUSTRALASIA
AUSTRALIA
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON 14
CARBON ISOTOPES
CENOZOIC ERA
CNIDARIA
CORALS
EARTH PLANET
EVEN-EVEN NUCLEI
GEOLOGIC AGES
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GROUND UPLIFT
HEAVY NUCLEI
ISLANDS
ISOTOPE DATING
ISOTOPES
LIGHT NUCLEI
NEW ZEALAND
NUCLEI
PACIFIC OCEAN
PLANETS
PLEISTOCENE EPOCH
QUATERNARY PERIOD
RADIOISOTOPES
REEFS
SEAS
SEDIMENTARY BASINS
SOUTHERN HEMISPHERE
SUBDUCTION ZONES
SURFACE WATERS
THORIUM 230
THORIUM ISOTOPES
URANIUM 234
URANIUM ISOTOPES
YEARS LIVING RADIOISOTOPES