The Ablah succession of Saudi Arabia (dating and geological significance)

The Ablah sedimentary succession represents a molasse basin in the Neoprote rozoic Shield of Saudi Arabia. A rhyolite flow interbedded in the successio n has been dated by the Pb/Pb method ar 641 +/- 1 Ma, indicating that the b asin is a local expression of Panafrican tectonism in the south of the shie ld. Consequently, the Panafrican phase that has previously been described i n the north can now be extrapolated to the south of dhe shield. This age de termination also enables post-Panafrican events, which differ between the s outh and the north, to be analysed over the entire shield. ((C) 1999 Academ ie des sciences / Editions scientifiques et medicales Elsevier SAS.)