These Layers Have The Same Direction And The Same Inclination As The Mica-Slate Of Araya.

Where the flank of the limestone mountains of New Andalusia is very steep we observe, as at Achsenberg, near Altdorf in Switzerland, layers that are singularly arched or turned.

The tints of the limestone of Cumanacoa vary from darkish grey to bluish white and sometimes pass from compact to granular. It contains, as substances accidentally disseminated in the mass, brown iron-ore, spathic iron, even rock-crystal. As subordinate layers it contains (1) numerous strata of carburetted and slaty marl with pyrites; (2) quartzose sandstone, alternating with very thin strata of clayey slate; (3) gypsum with sulphur near Guire in the Golfo Triste on the coast of Paria. As I did not examine on the spot the position of this yellowish-white fine-grained gypsum I cannot determine with any certainty its relative age.

([Footnote not indicated:] This sandstone contains springs. In general it only covers the limestone of Cumanacoa, but it appeared to me to be sometimes enclosed.)

The only petrifactions of shells which I found in this limestone formation consist of a heap of turbinites and trochites, on the flank of Turimiquiri, at more than 680 toises high, and an ammonite seven inches in diameter, in the Montana de Santa Maria, north-north-west of Caripe. I nowhere saw the limestone of Cumanacoa (of which I treat specially in this article) resting on the sandstone of the Llanos; if there be any such superposition it must be found on descending the table-land of Cocollar towards the Mesa de Amana. On the southern coast of the gulf of Cariaco the limestone formation probably covers, without the interposition of another rock, a mica-slate which passes to carburetted clay-slate. In the northern part of the gulf I distinctly saw this clayey formation at the depth of two or three fathoms in the sea. The submarine hot springs appeared to me to gush from mica-slate like the petroleum of Maniquarez. If any doubts remain as to the rock on which the limestone of Cumanacoa is immediately superposed, there is none respecting the rocks which cover it, such as (1) the tertiary limestone of Cumana near Punta Delgada and at Cerro de Meapire; (2) the sandstone of Quetepe and Turimiquiri, which, forming layers also in the limestone of Cumanacoa, belongs properly to the latter soil; the limestone of Caripe which we have often identified in the course of this work with Jura limestone, and of which we shall speak in the following article.

8. FORMATION OF THE COMPACT LIMESTONE OF CARIPE.

Descending the Cuchillo de Guanaguana towards the convent of Caripe, we find another more recent formation, white, with a smooth or slightly conchoidal fracture, and divided in very thin layers, which succeeds to the bluish grey limestone formation of Cumanacoa. I call this in the first instance the limestone formation of Caripe, on account of the cavern of that name, inhabited by thousands of nocturnal birds. This limestone appeared to me identical (1) with the limestone of the Morro de Barcelona and the Chimanas Islands, which contains small layers of black kieselschiefer (slaty jasper) without veins of quartz, and breaking into fragments of parallelopiped form; (2) with the whitish grey limestone with smooth fracture of Tisnao, which seems to cover the sandstone of the Llanos. We find the formation of Caripe in the island of Cuba (between the Havannah and Batabano and between the port of Trinidad and Rio Guaurabo), as well in the small Cayman Islands.

I have hitherto described the secondary limestone formations of the littoral chain without giving them the systematic names which may connect them with the formations of Europe. During my stay in America I took the limestone of Cumanacoa for zechstein or Alpine limestone, and that of Caripe for Jura limestone. The carburetted and slightly bituminous marl of Cumanacoa, analogous to the strata of bituminous slate, which are very numerous* in the Alps of southern Bavaria (* I found them also in the Peruvian Andes near Montau, at the height of 1600 toises.), appeared to me to characterize the former of these formations; while the dazzling whiteness of the cavernous stratum of Caripe, and the form of those shelves of rocks rising in walls and cornices, forcibly reminded me of the Jura limestone of Streitberg in Franconia, or of Oitzow and Krzessowic in Upper Silesia. There is in Venezuela a suppression of the different strata which, in the old continent, separate zechstein from Jura limestone. The sandstone of Cocollar, which sometimes covers the limestone of Cumanacoa, may be considered as variegated sandstone; but it is more probable that in alternating by layers with the limestone of Cumanacoa, it is sometimes thrown to the upper limit of the formation to which it belongs. The zechstein of Europe also contains a very quartzose sandstone. The two limestone strata of Cumanacoa and Caripe succeed immediately each other, like Alpine and Jura limestone, on the western declivity of the Mexican table-land, between Sopilote, Mescala and Tehuilotepec. These formations, perhaps, pass from one to the other, so that the latter may be only an upper shelf of zechstein. This immediate covering, this suppression of interposed soils, this simplicity of structure and absence of oolitic strata, have been equally observed in Upper Silesia and in the Pyrenees. On the other hand the immediate superposition of the limestone of Cumanacoa on mica-slate and transition clay-slate - the rarity of the petrifactions which have not yet been sufficiently examined - the strata of silex passing to Lydian stone, may lead to the belief that the soils of Cumanacoa and Caripe are of much more ancient formation than the secondary rocks. We must not be surprised that the doubts which arise in the mind of the geologist when endeavouring to decide on the relative age of the limestone of the high mountains in the Pyrenees, the Apennines (south of the lake of Perugia) and in the Swiss Alps, should extend to the limestone strata of the high mountains of New Andalusia, and everywhere in America where the presence of red sandstone is not distinctly recognized.

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