The late Lower (above Rich 3, Upper Emsian) and early
  Middle Devonian (Eifelian) of the Tata region in the eastern
  part of the Dra Valley has not yet been the subject of any
  detailed stratigraphical publication although it occupies an
  important palaeogeographical position between the more
  neritic southwestern part of the Anti-Atlas and of the
  predominantly pelagic Maider and Tafilalt regions of the
  southeastern Anti-Atlas.  Intercalating Emsian and Eifelian
  brachiopod and ammonoid faunas have been listed from the
  Jebel Hamsailikh S of Foum Zguid (HOLLARD &
  JAQUEMONT 1956), further to the NE, but have not yet been
  studied in detail. JANSEN (2001) concentrated on the
  Lochkovian to Lower Emsian sandstones and limestones
  with brachiopods of the Foum Zguid and Tata regions.
  SCHRAUT (2000) described Pragian trilobites from the same
  sections and localities of the Tata area.      The studied
  succession is characterized by a rather sudden change from
  early Emsian shallow-water sediments and faunas to late
  Emsian deeper-water facies, obviously caused by the peak
  of the global Daleje Event. There are no significant mixed
  neritic-pelagic faunas as further to the SW (Assa region).