Fission-track analysis was used to examine 13 basement samples of high-grade schist, pelitic gneiss, granite, migmatite, and calc-silicate rock, obtained from Ocean Drilling Program Hole 976B in the floor of the Alboran Sea. Long mean-track-length and tight length distributions, together with homogeneity of apatite age, indicate rapid cooling through the temperature range from 120° to 60°C at about 18-19 Ma. This cooling history represents exhumation within the top few kilometers of the earth's surface, and is therefore likely to date the creation of the present basement morphology in the area. The cooling age is very close to the age of the oldest sediments in the Alboran Sea, which indicates a close link in time between basement exhumation and creation of the Alboran Sea basin.
1Examples
of how to reference the whole or part of this volume can be found under "Citations"
in the preliminary pages of the volume.
2Research
School of Geological and Geophysical Sciences, University College London and
Birkbeck College, Gower Street, London WC1E 6BT, United Kingdom.
John.Platt@ucl.ac.uk
Date of
initial receipt: 23 April 1997
Date of acceptance: 1 October 1997
Reproduced
online: 20 November 2003
Ms 161SR-213