BLATB F0EMATI0K3. 
385 
most violence in the granitic soils of Caracas iind tlie 
Orinoco. Igneous phenomena (if their existence be really 
well certified) arc attributed by the people to the granitic 
peaks of Ouida and GuaracOj and also to the calcareous 
mountain of Ciichivano. 
From these observations, it results that gneiss-granite 
predominates in the immense group of the mountains of the 
Pariine, as niicaslate-gneiss prevails in the Cordillera of the 
coast; that in the two systems, the granitic soil, unmixed 
with gneiss and mica-slate, occupies hut a very small extent 
of country ; and that in the coast-chain the formations of 
clayey slate (thonschiefer), mica-slate, gneiss, and granite, 
succeed each other in such a manner on the same line from 
east to west (presenting a very uniform and regular inclina- 
tion of their strata towards the north-west), that, according 
to the hypothesis of a subterraneous prolongation of the 
strata, tlie granite of Las Trinchcras and the liincon del 
Diablo may be superposed on the gneiss of the Villa de 
Cura, of lineiiavista, and Caracas; and the gneiss super- 
posed in its turn on the mica-slate and clay-slate of Mani- 
quarez and Chuparuparu in the peninsula of Araya. This 
hypothesis of a prolongation of every rock, in some sort 
indefinite, founded on the angle of inclination presented by 
the strata appearing at the surface, is not admissible ; and 
according to similar equally vague reasoning, we should 
be forced to consider the primitive rocks of the Alps of 
Switzerland as supcrjiosed on the lormation of the compact 
limestone of Achsenberg, and that [transition, or identical 
with zechstein?3 in turn, as being superposed on the inolassus 
of the tertiary strata. 
II. FoRM.iTIOIf OF THE CLAT-SEATE (TnO>'SCniEEER) OF 
Mal'passo.— If, in the sketch of the formations ot Vene- 
zuela, I bad followed the received division into primitive, 
intermediary, secondary, and tertiary strata, I might be 
doubtful what place the last stratum of mica-slate ni the 
peninsula of Araya should occupy. This stratum, in the 
ravine (aroyo) of Ilobalo, iiasses insensibly in a carburetted 
and shining slate, into a real ampelite. The direction and 
inclination of tlio stratum remain the same, and the thon- 
Bchiefer, which takes the look of a transition-rock, is but a 
2 c 
