In The Latter Place He Founded The City Of Caracas.), And From The Ancient Gold-Mines Of Baruta And Oripoto.

Ascending in the direction of Carapa, we enjoy once more the sight of the Silla, which appears like an immense dome with a cliff on the side next the sea.

This rounded summit, and the ridge of Galipano crenated like a wall, are the only objects which in this basin of gneiss and mica-slate impress a peculiar character on the landscape. The other mountains have a uniform and monotonous aspect.

A little before reaching the village of Antimano we observed on the right a very curious geological phenomenon. In hollowing the new road out of the rock, two large veins of gneiss were discovered in the mica-slate. They are nearly perpendicular, intersecting all the mica-slate strata, and are from six to eight toises thick. These veins contain not fragments, but balls or spheres of granular diabasis,* formed of concentric layers. (* Ur-grunstein. I remember having seen similar balls filling a vein in transition-slate, near the castle of Schauenstein in the margravate of Bayreuth. I sent several balls from Antimano to the collection of the king of Spain at Madrid.) These balls are composed of lamellar feldspar and hornblende closely commingled. The feldspar approximates sometimes to vitreous feldspar when disseminated in very thin laminae in a mass of granular diabasis, decomposed, and emitting a strong argillaceous smell. The diameter of the spheres is very unequal, sometimes four or eight inches, sometimes three or four feet; their nucleus, which is more dense, is without concentric layers, and of a very dark green hue, inclining to black. I could not perceive any mica in them; but, what is very remarkable, I found great quantities of disseminated garnets. These garnets are of a very fine red, and are found in the grunstein only. They are neither in the gneiss, which serves as a cement to the balls, nor in the mica-slate, which the veins traverse. The gneiss, the constituent parts of which are in a state of considerable disintegration, contains large crystals of feldspar; and, though it forms the body of the vein in the mica-slate, it is itself traversed by threads of quartz two inches thick, and of very recent formation. The aspect of this phenomenon is very curious: it appears as if cannon-balls were embedded in a wall of rock. I also thought I recognized in these same regions, in the Montana de Avila, and at Cabo Blanco, east of La Guayra, a granular diabasis, mixed with a small quantity of quartz and pyrites, and destitute of garnets, not in veins, but in subordinate strata in the mica-slate. This position is unquestionably to be found in Europe in primitive mountains; but in general the granular diabasis is more frequently connected with the system of transition rocks, especially with a schist (ubergangs-thonschiefer) abounding in beds of Lydian stone strongly carburetted, of schistose jasper,* (Kieselschiefer.) ampelites,* (Alaunschiefer.) and black limestone.

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