257 



quantity of petrified sea-shells, united by a cal- 

 careous cement, in which are mingled grains of 

 quartz ; fourthly, near the point of Barigon, 

 whence the stone employed for building at Cu- 

 mana is drawn, banks of yellowish white shelly 

 lime-stone, in which are found some scattered 

 grains of quartz ; fifthly, at Pennas Negras, at 

 the top of the Cerro de la V ela, a bluish gray 

 compact lime-stone, very tender, almost without 

 petrifactions, and covering the schistose sand- 

 stone. However extraordinary this mixture of 

 sand-stone and compact lime- stone * may ap- 

 pear, we cannot doubt, that these strata belong 

 to one and the same formation. The very recent 

 secondary rocks every where present analogous 

 phenomena ; the molasse of the Pays de Vaud 

 contains a fetid shelly lime-stone, and the cerite 

 lime-stone of the banks of the Seine is sometimes 

 mixed with sand-stone f- 



The strata of calcareous breccia, which can 

 be best examined in going along the rocky coast 

 from Punta Gorda to the castle of Araya, are 

 composed of an infinite number of sea shells, 

 from four to six inches in diameter, and in part 

 well preserved. We find they contain not am- 

 monites, but ampullaires, solens, and terebra- 

 tulse. The greater part of these shells are 



* Dichter kalk stein, 

 f Cuvier and Brongniart, Geogr. min. des Environs de 

 Paris, 1811, p. 18, 25, and 135. 



