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During my stay in America I took the limestone of Cumanacoa for zechstein or Alpine limestone, and that of Caripe for Jura limestone. There is in Venezuela a suppression of the different strata which, in the old continent, separate zechstein from Jura limestone.
There are 25 Gasteropods and only one cephalopod, Nautilus Freieslebeni, which is also found in the German Zechstein. Spirifera alata, Schloth. Syn. Trigonotreta undulata, Sowerby., King's Monograph. King and Howse.
The marly gypsum, of which we collected specimens near the Carib mission of Cachipo, appeared to me to belong to the same formation as the gypsum of Ortiz. To class it according to the type of European formations I would range it among the gypsums, often muriatiferous, that cover the Alpine limestone or zechstein.
Now those names cannot remain the same if, after further examination, the objects of comparison have not retained the same place in the geologic series; if the most able geologists now take for transition-limestone and green sandstone, what they took formerly for zechstein and variegated sandstone.
Wealden : Weald-formation. Portland : Upper oolithic. Oxford : Middle oolithic. Bath : Lower oolithic. Lias : Liassic. Keuper : Upper triassic. Muschelkalk : Middle triassic. Bunter : Lower triassic. Permian : 14. Zechstein : Upper permian. Permian : 13. Neurot sand : Lower permian. Carboniferous sandstone : Upper carboniferous. Carboniferous limestone : Lower carboniferous.
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.
I believe the surest means by which geologic descriptions may be made to survive the change which the science undergoes in proportion to its progress, will be to substitute provisionally in the description of formations, for the systematic names of red sandstone, variegated sandstone, zechstein and Jura limestone, names derived from American localities, as sandstone of the Llanos, limestone of Cumanacoa and Caripe, and to separate the enumeration of facts relative to the superposition of soils, from the discussion on the analogy of those soils with those of the Old World.*
The meridian altitude of the fourth day must have been reached where for the first time the covering of vapor and clouds of the earthly atmosphere permanently parted, and sun, moon, and stars became visible: and geology finds this time in the period which lies between the carboniferous period and the trias in the Permian period, as it is called in England, in the dyas of the fossiliferous and of cupriferous slate and Zechstein, as we call it in Germany.
These strata are less connected by alternation than by opposition. Porphyritic breccias which envelope the quartzose porphyries. The gem-salt oscillates from zechstein to muschelkalk. Tertiary strata, showing a much smaller number of dicotyledonous plants. These alternations and transitions appeared to me less common in the littoral Cordillera of Venezuela than in the Sierra Parime.
It is here a blackish grey, of compact fracture, tending sometimes towards the sandy fracture, and crossed by small veins of white carbonated lime. I saw no petrifactions in it; but the inhabitants assert that considerable masses of shells are found at great heights. The alpine limestone and the zechstein, famous among the geologists of Freyberg, are identical formations.
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