The karst of Mallorca Island (Balearic Archipelago, Western Mediterranean) is characterised by the occurrence of many coastal caves, where phreatic speleothems accrete today, around conventional vadose-zone speleothems in correspondence with the current sea level. Older deposits of this kind of carbonate precipitates have recorded ancient high and low sea stands by means of strictly horizontal alignments of the phreatic overgrowths on speleothems (POS) respectively located above and below present sea level. Mallorca has proved to be a good location for investigations on eustatic sea level changes because it is located far from the former margins of the major ice-sheets and was only affected by a minor tectonic tilt since the end of marine oxygen isotope stage (OIS) 5e. A number of POS now located above and below present sea level have been dated by the U-series method using MC-ICPMS and TIMS. The obtained high precision ages fall within a time interval ranging form 144 to 78 ka ago and provide constraints on sea level changes curve during the last interglaciation in Mallorca. Three high stand have been recognised corresponding to OIS 5e (138 ? 128 ka and 122 ? 110 ka) and OIS 5a (84 ? 82 ka) separated by very fast sea level falls. The resulting eustatic curve emphasises the occurrence of marine level fluctuations greater than 18 m in amplitude within short time spans (< 5 ka)
Tuccimei, P., Gines, J., Gines, A., Gracia, F., Fornos, J.J. (2006). U-series ages of phreatic overgrowths on speleothems in coastal caves of Mallorca (Spain). New ICP-MS data for the construction of a sea level changes curve for the Last Interglacial in the Western Mediterranean, 50, 1-21.
U-series ages of phreatic overgrowths on speleothems in coastal caves of Mallorca (Spain). New ICP-MS data for the construction of a sea level changes curve for the Last Interglacial in the Western Mediterranean.
TUCCIMEI, Paola;
2006-01-01
Abstract
The karst of Mallorca Island (Balearic Archipelago, Western Mediterranean) is characterised by the occurrence of many coastal caves, where phreatic speleothems accrete today, around conventional vadose-zone speleothems in correspondence with the current sea level. Older deposits of this kind of carbonate precipitates have recorded ancient high and low sea stands by means of strictly horizontal alignments of the phreatic overgrowths on speleothems (POS) respectively located above and below present sea level. Mallorca has proved to be a good location for investigations on eustatic sea level changes because it is located far from the former margins of the major ice-sheets and was only affected by a minor tectonic tilt since the end of marine oxygen isotope stage (OIS) 5e. A number of POS now located above and below present sea level have been dated by the U-series method using MC-ICPMS and TIMS. The obtained high precision ages fall within a time interval ranging form 144 to 78 ka ago and provide constraints on sea level changes curve during the last interglaciation in Mallorca. Three high stand have been recognised corresponding to OIS 5e (138 ? 128 ka and 122 ? 110 ka) and OIS 5a (84 ? 82 ka) separated by very fast sea level falls. The resulting eustatic curve emphasises the occurrence of marine level fluctuations greater than 18 m in amplitude within short time spans (< 5 ka)I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
