585 



superposed, that the sandstone of the Impossible, 

 and the Aguas calientes, constitute the same 

 soil. The muriatiferous clay (with petroleum and 

 lamellar gypsum) cover the western part of the 

 peninsula of Araya, opposite the town of Cu- 

 mana, and at the center of the island of Mar- 

 guerita. This clay appears placed immediately 

 by micaslate, and covered by the calcareous 

 brechia of tertiary soil. I shall not decide if 

 Araya, rich in disseminated muriate of soda* 

 belongs to the formation of sandstone of the 

 Impossible, which from its position may be 

 compared to variegated sandstone (red marl). 



Fragments of tertiary soil surround indubi- 

 tably the castle and town of Cumana (Castillo de 

 San Antonio), and they also appear at the south- 

 west extremity of the peninsula of Araya (Cerro 

 de la Vela et del Barigon) ; at the ridge of 

 Meapire, near Cariaco ; at Cabo Blanco, on the 

 west of la Guayra, and on the shore of Portoca- 

 bello ; they are found consequently at the foot 

 of the two slopes of the northern chain of the 

 Cordillera of Venezuela. This tertiary -f* soil 

 is composed of alternate beds of calcareous 

 aglomerats, compact limestone, marl, and clay, 

 containing selenite, and lamellar gypsum. This 



* Vol. iii. p. 94. 



t Vol. ii, p. 266—269, 290, 291 ; Vol. iii, p, 204 ; Vol. 

 vi, p. 93. 



