Evidence of high sea level during isotope stage 5c in Queensland, Australia
Australie ; Corallien ; Datation 230Th/234U ; Datation radiométrique ; Dune littorale ; Eolien ; Géographie physique ; Haut niveau marin ; Niveau marin ; North Stradbroke Island ; Paléorivage ; Paléosol ; Pléistocène supérieur ; Podzol géant
Thirty-nine species of scleractinian corals, associated with thin intertidal sediments, have been recovered from under a high dune on the western (mainland) side of North Stradbroke Island, eastern Australia. Three species yielded a mean 230Th/234U
age of 105,000 yr BP. The corals provide evidence of a sea stand near present sea level during isotope Stage 5c, which is considerably higher than previously suggested for this period. Their good condition implies that the overlying parabolic dune
is of comparable age and formed during that high stand of sea level. Also, the isotope age provides a maximum period for the development of giant podzols in the podzol chronosequences on coastal dunes in southern Queensland.
The Sayif travertines and lacustrine limestones cropping out in the northern Arava Valley, a region of extreme aridity, have been dated by the 230Th/234U disequilibrium method. Most of the ages fall within two clusters that are coincident with ages
representative of oceanic oxygene-isotope stages 5 and 7. The colder intervening stage 6 was not a period of substantial travertine formation. During the warmer global episodes of isotopic stages 5 and 7 the arid south of Israel apparently was considerably wetter
Paleoclimatic significance of the stable isotopic composition and petrology of a Late Pleistocene stalagmite from Botswana
Botswana ; C 14 dating ; Cave ; Climatic variation ; Isotope analysis ; Oxygen 18 ; Palaeo-environment ; Pleistocene ; Quaternary ; Th/U dating
alteration of the carbonate explains the deviation between the 230Th/234U and 14C age determinations relative to proposed external conditions (4 new 230h/234U ages determined by mass spectrometry are presented.
Samples of corals from all three previously reported localities in eastern Australia have been dated anew the 230Th/234U technique. Results for two sites are confirmed, but the new results for the third site are older than previously reported and do
not support a high sea level for isotope substage 5 c. All sites are now referred to substage 5c.
datation 230Th/234U et He/U des terrasses coralliennes: l'étage 5 correspond aux terrasses de Worthing (82000BP), Ventnor (105000BP) et Rendezvous Hill (125000BP), l'étage 7 aux terrasses de Kendal Hill (180000BP), Kingsland (200000BP) et Aberdare (220000BP
Seven dates have been produced, using the 230Th/234U dating method on six samples of speleothems collected in a cave, recently discovered in Gaspésie. Ages obtained range between 102000 and 223000 years B. P. The absence of redissolution traces
Cinétique du concrétionnement dans quelques grottes belges: apport des datations 14C et 230 Th/234U. (Kinetics of speleothems growth in some Belgian caves as inferred from 14C and U-series dating)
which are in the range of the applied methods (about 0-30 ka BP and 5-350 ka BP for 14C dating and 5-350 ka BP for 230Th/234U dating). Speleothems developed in Holocene and Eemian show vertical growth rates from 0,2 to 0,3 cm. 100 Years I. (LW).
Over 60 14C analyses on speleothems. First results of 230 Th/234U dating indicate a period of speleothem growth between 85 and 130 ka BP. A slowdown or maybe an interruption of the calcite deposition occurred during the cold phases of the Quaternary
Reevaluation of the lake-sediment chronology in the Dead Sea Basin, Israel, based on new 230Th/U dates
Dating ; Dead Sea ; Geochronology ; Isotope analysis ; Israel ; Lacustrine sediment ; Lake level ; Palaeogeography ; Stratigraphy ; Th/U dating
The Dead Sea is surrounded by chemical and detrital sediments that where deposited in its larger precursor lakes, Lake Samra and Lake Lisan. The sedimentary history of these lakes was reconstructed by means of 230Th/234 U ages of 30 samples
. The general validity of the ages was demonstrated by subjecting them to tests of internal isotopic consistency, agreement with stratigraphic order, and concordance with 14C ages.
Corals from the Seychelles Islands, Indian Ocean, occur mainly as small coralline algae-vermetid remnants found in cavities adhering to the rock surface. This paper presents results of new TIMS 238U-234U-230Th measurements on coral samples from
Baja California ; California ; Coral reef ; Geochemistry ; Isotope analysis ; Marine quaternary ; Marine terrace ; Mexico ; North Pacific Ocean ; Oregon ; Sea level ; United States of America ; Uranium
Corals from marine terrace deposits of the Pacific coast of North America show some open-system effects with respect to U isotopes. Secondary addition of 234U is observed and implies that some apparent ages are probably minima. Some variability
Inactive stalagmites from the Silberen cave system and its surroundings (Muota Valley, Central Switzerland) have been dated by the 230Th/U method (alpha spectrometry and TIMS). The following complementary dating methods were applied : 234U/238U
This study aims to determine the neotectonic activity of the Manisa Fault and the most recent time of the change in its stress condition through age-dating data obtained by using 230Th/234U dating methodology applied on the calcite coating
of Xian. Twelve speleothems samples near the position of palaeowater tables in three cave passages are dated by the 230Th dating method. The results show that these events are close to the interglacial transitions following marine oxygen isotope stages 10
New archeomagnetic and 226Ra-230Th dating of recent lavas for the Geological map of Etna volcano
to reconstruct a coherent sequence of eruptions, and ii) a multidisciplinary approach is necessary to obtain a comprehensive eruptive history of such a very active volcano. Thanks to these new archeomagnetic and 226Ra-230Th data coupled with stratigraphic data
La basse terrasse corallienne pleistocène (Eemien) de la Guadeloupe : morphologie, datations 230Th/234 U, néotectonique
Etude morphologique et datations 230Th/234 U de la basse terrasse corallienne décrite à Grande Terre de la Guadeloupe, Marie Galante et la Désirade. Mise en évidence d'une néotectonique postéémienne active : subsidence de caractère volcano
La datation par la méthode des déséquilibres des familles de l'uranium (234U/230) d'ossements et de planchers stalagmitiques provenant des niveaux moustériens de l'Abri des Pêcheurs (Casteljau, Ardèche) a permis de donner des points de repère