GEOLOGY OF MAROCCO AND GREAT ATLAS. 463 



occurs from the cliff north of SaiE. to the plateau skirting 

 the Atlas, representing the whole of the Cretaceous epoch ; but 

 it is also open to question whether the level beds of the plain 

 may not be an inland extension of the strata of Miocene age 

 from which Dr. Hooter obtained fossils at the Jew's Cliff south 

 of Saffi. 



(d) Grey Shales. — At several points on entering the lateral 

 valleys of the Atlas, almost vertical shaly beds are crossed, 

 having a strike nearly east and west, corresponding with the 

 trend of the chain. They clearly underlie, and are unconform- 

 able to, the Red Sandstone and Limestone series ; and their 

 almost vertical position appears connected with one of the 

 several upheavals that have affected the chain. Of their 

 geological age there is no evidence, except that they are pre- 

 Cretaceous. In places, as at Assghin, they abound in nodules 

 of carbonate of iron. Pale shales, containing quartz veins, crop 

 up near the village of Frouga, in the plain south-west of 

 Marocco, which may possibly belong to this series ; and if the 

 porphyries forming the mass of the Atlas are contemporaneous, 

 they are probably interbedded with these gi'ey shaly beds. 

 Lieut. Washington speaks of the occurrence of clay-slate 

 dipping 45° east between El Mansoria and Fidallah, and again 

 of a hilly country of clay-slate near the plain of Smira, and at 

 Peira, farther south ; but it is impossible to say whether these 

 beds are related to the grey shales of the Atlas. 



(e) Metamorphic Rocks. — The most important development 

 of metamorphic rocks in the neighbourhood of Marocco is on 

 the north side of the city. In its immediate neighbourhood, 

 three miles to the north-west, a low rugged hill occurs, composed 

 of a very hard and compact dark-grey rock, containing knotted 

 white concretions elongated in the line of stratification, which 

 dips from 50° to 80° south-west, the strike being north west and 

 south-east. The whole of the north side of the plain is 

 bounded by ranges of rugged hills of similar form, and 

 apparently rising from 2,000 to 3,000 feet above the plain. We 

 had not an opportunity of visiting them ; but, judging from 

 their outline, they are identical in formation with the hill close 

 to Marocco. We observed nothing ia the Atlas resembling it. 

 Lieut. Washington, who crossed these hills on his journey to 

 Marocco at about the point I visited, and again forty miles to 



