Late cretaceous muwaqqar formation ammonites in Southeastern Jordan

Abstract EN

Three Maastrichtian ammonite species belonging to two families, were recorded in the upper part of Muwaqqar Formation (MCM).

Two planispiral species belong to the family, namely, Sphenodiscidae, Sphenodiscus lobatus and Libycoceras ismaeli while the third, straight species, belongs to Baculitidae family; Baculites sp.

The Paleocene strata are represented by 6 m in the measured section below the Rijam Formation.

This might indicate a long erosional unconformity at the end of the MCM which was documented by other workers several tens of kilometers west of the study area.

The erosional unconformity is also supported by the presence of tree trunks at the Muwaqqar-Rijam formations contact.

Microfacies analysis indicates that the upper Muwaqqar Formation in the Jebal Khuzayma area was deposited in an offshore, open marine conditions affected by upwelling currents.

This is evidenced by the abundant planktonic fauna exceeding benthic fauna, the abundant matrix represented by lime mudstone, and the relatively high phosphate particles and organic matter.