In Yemen, the outcropping Cretaceous System consists of continental and
marine clastics and carbonates which are distributed in three main lithofacies:
continental (in northern provinces), transitional (in western parts of southern
provinces), and
marine (in eastern parts of southern provinces). These are
included within the Tawilah Formation and Ahwar/Mahra Groups. The
occurrence of the Tawilah Formation (Cretaceous-Paleocene) is restricted to
the northern provinces. Its lower parts consist of continental (fluvial)
sandstones (continental lithofacies) of Cretaceous age which constitute the Zone
without diagnostic fossils. Its upper parts consist of alternations of nonmarine
and fossiliferous marine sandstones of Paleocene age which constitute the
Pulsiphonina prima Zone.
