Geological Delineation of Sonth America^ 1 77 



and as has been incntioned by that excellent geologist M. 

 Von Buch, in his Miueralogical Description of the County 

 of Glatz in Silc,>?ia, a small work, which contains valuable 

 ideas and interesting observations. 



1 found here two^fonnations of compact limestone. The 

 one makes a transition into the small grained and imper- 

 ceptibly foliaceous limestone, and is identic with the lime- 

 stone of the high Alps; the other is compact, exceedingly 

 homogeneous, with several petrifactions of shells, and ana- 

 logous to the limestone of Jura, Pappcnhcim, Gibraltar, 

 X'crona, Dalmatia, and Suez 5 a formation of foliaceous 

 gypsum, and another mixed with clay, containing common 

 salt and rock oil. The saline clay which I always found 

 accompanied with rock salt in the Tyrol, Steyermark, and 

 Salzbourg in Swisserland ; marl schist stratified in lime- 

 stone of the Alps, and two formations of sandstone, one 

 of which is older and almost without petrifactions, some- 

 times small and large-grained sandstone of i\v: llanos, and 

 >hc other full of the remains of marine animals, which 

 fonns the transition into the compact limestone. 



The blue limestone of the Alps, with white veins of cal- 

 careous spar, is found on the micaceous schist lying upon 

 the Quebrada Secca near Tuy to the east from the Punta 

 Dclgada, on the road from Cumana, on the Impossible 

 towards Bordones, on the island of Trinidad, and on the 

 mountain Paria. This limestone contains here, as in Swis- 

 serland, three formations arranged under each other : — • 

 1st, Repeated strata of black marl schist; marl schist, or 

 cupreous schist ofThuringia, mixed with pyrites, and earth 

 pitch on the Cuchivana near Cumanacoa. This clay con- 

 tains carbon, and absorbs the oxygen of the atmospheric 

 air. 2d, Saline clay mixed with i-ock salt and crystallized 

 gypsum, in which the salt pits of Araga, Pozuelas, and 

 Margaret's Island are placed. 3d, Small-grained sand- 

 stone, with a calcareous base, almost without petrifactions 

 of shells, always penetrated by water, and sometimes w ith 

 brown strata of ferruginous earth on the Cocollard, Tamir- 

 quiri. I am not certain whether the last-mentioned stone 

 lies on the limestone, or is not sometimes covered by it. 



This limestone serves as the base for a newer one. It is 

 exceedingly white and compact, full of holes (Cueva del 

 Ouacharo, in which thousands of birds reside, and among 

 which is a new genus of Caprimulgus, from which a kind 

 of fat much used in the country is obtained, Cueva del 

 S. Juan, Cueva del Cuchivano) ; sometimes porous like 

 the Franconian, and forms grotesque rocks (Morros de 

 . Vol. XVIII. No. 70. M S. Juan 



