BA>'J)STOS"E formations. 
i73 
diately covers tlie sandstone of Calabozo, wMcli appeared to 
me on the spot, to be identical with our red sandstone, 
I am uncertain of the age of its formation. The secondary 
rocks of the Llanos of Cumana, Barcelona, and Caracas, 
occupy a space of more than 5000 square leagues. \^eir 
continuity is the more remarkable, as they appear to have 
no existence, at least on the east of the meridian of Porto 
Cabello (70° 37') in the whole basin of the Amazon, 
not covered by granitic sands. The causes which have 
favoured the accumulation of calcareous matter in the eastern 
region of the coast chain, in the Llanos of Venezuela (from 
10A° to 8° north), cannot have operated nearer the equator, 
in the group of the momitains of the Panme, and m the 
plains of the Eio Negro and the Amazon (lat. 1 north, to 1 
south). The latter plains however, furnish some ledges of 
fran-mentary rocks, on the south-west of San Fernando de 
Atabapo, as well as on the south-east, in the lower ppt ot 
the Eio Negro and the Eio Branco. I saw m the plains ot 
Jaen de Bracamoros a sandstone which alternates with ledges 
of sand and conglomerate nodules of porphyry and Lvdian 
stone. MM. Spix and Martius affirm that the banks of 
the Eio Negro, on the south of the equator, are composed ot 
variegated sandstone; those of the Eio Branco, Jupura, and 
Apoporis, of quadersandstein ; and those of the Amazon, on 
several points, of ferruginous sandstone.* It remains to 
examine if (as I am mclined to suppose) the limestone and 
gypsum formations of the eastern part ot the httoral Cordil- 
lera of Venezuela differ entirely from those ot the Llanos and 
to what series belongs that rocky wallf named the (xalera, 
» Braunes eiscnschUssiges Sandstein-Conglomerat (Iron-sand of the 
English geologists, between tlie Jura Umestone and green sandstone.) 
MM. Sp?x and Marlins found on rocks of out 
Apoporis and the Japura, the same sculptures which we hp m Itte 
frL^the Essequibo to the plains of InditIt 
the migrations of a people more advanced in civilization than the Indians 
vho now inhabit those countries. - . , -x nf nii&der« 
t Is this wall a succession of rocks of dolomite or a dyke of quader. 
sandstein, Uke the Devil’s Wall (Teufelsmaoer), at foot of the Hart,^ 
Calcareous shelves (coral banks), either ledges of sandstone (e«oots ot tne 
revXontftLwaUorvolca’nm 
borders of great plains, that is, on the sliores of 
Llanos of Venezuela furnish e.xamples of such eruptions nea. Barais— i. 
