Geological Delineation of South America, 1 73 



twcen Valencia and St. Carlos, and that of Sierra Neveda 

 de Merida, contain, like that of St. Gothard, fissures which 

 are covered with very beautiful and large rock crystals. 



The granite is covered with gneiss and micaceous schist, 

 particularly on the cordillera of the coast of Venezuela. 

 Gneiss is abundant in particular from Cape Chichibocoa to 

 Cape Codcra in the Tcquez, Cocuiza, and the mountain 

 Guignc, as well as in the islands of the Lake of Valencia, 

 where I found (on Cape Blanc, opposite toGuacara,) blackish 

 quartz in tlie gneit^s which passes into Lydian stone, or 

 rather into the schistous state of VV^erner. The Macanao 

 on Margaret's island, and the whole cordillera on the isth- 

 mus of Cariaco, is nothing else than micaceous schist full 

 of red garnets ; and at Maniquarez it is combined with a 

 little cyanite. Green garnets are intermixed with the gneiss 

 of the mountain Avila. in the gneiss of the rock Cala- 

 micari in Cassiquiare, and in the granite of Las Trincheras 

 near V^alencia, I saw round masses, from three to four 

 inches in diameter, interspersed, which consisted of finer 

 grained granite, yellow feldspar, a great deal of quartz, and 

 scarcely any mica. Is this old granite contained in some 

 of later formation, or are these masses, which have the ap- 

 pearance of accumulations, merely the effect of attraction, 

 which here and there made the particles to approach nearer 

 to each other, but at the same time that the whole moun- 

 tain was formed ? This phrsnomenon of one kind of gra- 

 nite interspersed in the other is observed also in Silesia, at 

 Wuusiedel, on the Fichtelberg, in Chamouni, on St. Ber- 

 nard, on the Escurial, and m Galicia. Nature is uniform 

 in her natural productions, even to the small variations in 

 proportions. 



The micaceous schist passes into talc schist in the cor- 

 dillera of the coast, on the mountain Capaya, and on the 

 ()uebrada Sccca, in the valley del Tuy. In the cordillera 

 of Pariraa talc is found in very large shining masses, and 

 this has contributed so much to the celebrity of the Do- 

 rado, or Cerro Ucucuamo, between the river Es<|uivo and 

 Mao, in the island Pumaoena. The bright iiery appearance 

 exhibited sometimes bv the truncated pyramids of the large 

 Cerro Calitamini, near Cunavami, at sun-setting, seems also 

 to proceed from a stratum of talcy schist cut perpendicu- 

 larly to"A ards the west. 



Small idols of nephrite, which I saw brought from Ero- 

 vato, show that to the south of Raudal de Mura there are 

 nephrite rocks in gneiss like those I found at the bottom of 

 St. Gothaid, near Urfcrn. This formation \\ as repeated by 



nature 



