1887

### Abstract

In Saudi Arabia, a pre-Buwaib unconformity was mentioned by Powers et al., (1966) on bases of angular discordance and of biostratigraphic changes. According to the Hauterivian and Valanginian ages assumed for Buwaib and underlying Yamama formations respectively by Powers, this unconformity should be equivalent to the late Valanginian unconformity. In fact, both arguments given by Powers for this unconformity were since subject to objection. Therefore, based on previous geological mapping by BRGM-DMMR and on two recent maps by SGS, we discuss the pre-Buwaib unconformity in outcrop and the age of the hiatuses from lat. 26°N to lat. 21°N. This formation is associated to the cycle GSS K30 and the Late Valanginian unconformity is thus identified as the pre-Biyadh unconformity and not as the pre-Buwaib unconformity.

/content/papers/10.3997/2214-4609.20142795
2012-12-09
2020-10-27