256 



tie of St. Antony rises, is covered with very re- 

 cent formations of sandstone and clay mixed with 

 gypsum. Perhaps these same formations for- 

 merly filled the longitudinal valleys, now occu- 

 pied by the ocean ; and perhaps they favoured 

 the irruption of the waters, by making less re- 

 sistance than the mica-slates and Alpine lime- 

 stone. Near Maniquarez a breccia or sand- 

 stone with calcareous cement, which might ea- 

 sily be confounded with a real limestone, is 

 placed immediately on the mica-slate ; while on 

 the opposite side, near Punta Delgada, this sand- 

 stone covers a compact, bluish gray lime-stone, 

 almost destitute of petrifactions, and traversed 

 by small veins of calcareous spar. This last 

 rock is analogous to the lime-stone of the high 

 Alps*. 



The very recent sand-stone formation of the 

 peninsula of Araya contains, first, near Punta 

 Arenas, a stratified sand-stone, composed of very 

 fine grains, united by a calcareous cement in 

 small quantity ; secondly, at the Cerro de la 

 Vela, a schistose sand-stone-}-, without mica, 

 and passing into slate-clay which accompa- 

 nies coal ; thirdly, on the western side, between 

 Punta Gorda and the ruins of the castle of St. 

 Jago, a breccia composed of an innumerable 



* Alpenkalkstein. 

 t Sandsteinschiefer. 

 % SchSeferthon. 



