Korn, Klug & Reisdorf, 2000, p.72:

El Atrous North (15 km northwest of Taouz): This section  is located 500 m cast of the Frasnian-Famennian
Boundary stratotype candidate (BECKER et al., 1988). The crinoid limestones are here 8.20 m thick and, as in
preceding outcrop, overlain by a black ammonoid packstone that contains a.rich fauna with Platyclymenia
annulata.  The outcrop is partly covered bv scree from fossil mining, but is 80 cm higher, and a 10 cm thick
black platy limestone is exposed that yielded a fauna dominated by Cvmaclymenia sp.  After another small
covered portion, the Gonioclymenia Limestone follows.