1804.] 7 
ftructure, the fame direétion, and the fame 
inclination of the ftrata. The three hol- 
lows, or valleys of Caracas, Aragua, and 
Monai, are remarkable on this account, 
that the level of them is above the furtace 
of the fea ; they become lower by grada- 
tions, and the higheft ftep is the eaftern, 
which may ferve as a proof that they were 
formed at an earlier period than the.Lla- 
nos, whofe declivity proceeds from eati to 
wett, like. the whcle continent of South 
America. By repeated barometric mea- 
furement I found the height of. the val- 
leys of Caracas to be 416 toifes, of Ara- 
gua 212 toifes, above the furface of the 
fea ; the Llanos of Monai, the we(tern ba- 
fon; appears to have an elevation of no 
more than eighty or one hundred. toifes.— 
The valley of Caracas has once “been a 
lake, which formed for itfelf an-efflux 
through the Quebrada de Tipe, Catia, 
and Rio Mamon ; the bafon of Aragua 
appears, on the other hand, to have be- 
come dry by gradual evaporation ; for 
the remains of the old water (loaded with 
muriate of Jime,) are {ill feen in the lake 
of Valencia, which becomes lefs every 
year, and difcovers iflands which are 
known uncer the name of Aparecidas.— 
The height of the cordijlera of the coaft 
is commonly from 600 to 800 toifes ; the 
highelt peaks, Sierra de Nevada de Meri- 
da and the Silla de Caracas, (to which we 
undertook a laborious journey with our 
inftruments,) are 2350 and 136 toifes in 
height. To the welt they always become 
lower, and the height of Cape Codera is 
only 176 teifes. The Macanao, on the 
ifland Margaretha, which J meafured tri- 
gonometrically, isnot more in height than 
342 toiles; but this fpeedy depreifion 
takes place only in the. primitive moun-. 
tains of the cordillera. On the eaftern 
coalt fecondary accumulations of lime 
rile from Cape Unare to a more. confider- 
able height than the gneis and micaceous 
{chiftus ; thefe calcareous rocks, which 
are covered with fanditone of a calcareous 
bafe, and which accompany the cordillera 
of the coaft in its fouthern declivity, are 
very low on the fide towards Cura, but 
rife in a mafs towards the eaftern extremi- 
ty of the continent, 
In Bergantin they are 702 toifes high, 
in Coccollard 392, in Cucurucho du Tu- | 
miniquiri (the highett fummits of the pro- 
vince of Cumana) 976 toifes, and the py- 
ramid of the Guacharo rifes above 820 
toifes: from Cape Unare they form a fe- 
parate ridge of mountains, in which the 
original ridge totally difappears; they 
are conneéted alfo with the micaceous 
MontTuiy Mage. No. 113, 
Geological Defcription of South America, 
"933 
fchiftous cordillera_of Maniquare and 
Paria only by the Cerro de. Meapire, 
which, analogous to the branches of ‘To- 
rito and los Teques, which fepara'e the 
bafons of Monai, Aragua, and Caracas, 
“extends north and fouth from Guacharo 
and Catouaro, to the mountain Paria, and 
feparates the valley of Cariaco (the dried- 
up bank of the Gulf of Cariaco) from the 
valley of St. Boniface, which formerly 
belonged to the Golfo Trifte.. It will be 
feen hereafter, that the accumulation of 
calcareous formation on the eaftern part 
of the coaft of this country feems to have 
been more expo‘ed to earchquakes; and 
that the Cerro de Meapire, at the time of 
the irruption of the Gulf of Cariaco, and 
the Golfo Trifte, prevented the water 
from converting the land of Araya and 
the ridge of Paria intoan ifland. i 
-The declivity of the cordillera of th 
coaft of Venezuela is gentler towards the 
fouth than towards the north, which is 
particularly firiking when one defcends 
from the heights of Guigue, through St. 
Juan, Parapara, and Ortiz, towards the 
Mera de Paja, which belongs to the great 
Llano de Calabozo. The northern de. . 
clivity is every where very fteep, and 
there is {carcely found, Mont Blanc ex-: 
ceptec, above Courmayeur, a more 
frightful precipice than the perpendicular 
wall of Silla de Caracas, beyond Caraval- 
ledo, which rifes to the height of 1300 
toifes. An accurate meafurement of this 
wall of rock was of great importance to 
navigators, as they could find its diftance 
from the coaft only by taking the angle 
of its elevation: its longitude, therefore, 
of 60° 37’ 32” weft from Paris will en- 
able them to dilcover it. 
The phenomenon of a more gentle de- 
clivity towards the fourth feems to contra- 
diét the obfervations made in ocher cordil. 
leras of the earth, as it is afferted that 
they all decline more abruptly towards 
the fouth and wet. This contrad ction, 
however, is only apparent; as the nar:h- 
ero part of the cordillera, during the great 
cataftrophe which produced the Gulf of 
of Mexico, was torn away by the force 
of the water ; and therefore the northern 
declivity might at that time be gentler 
than the fouthern. . 
If the form of the coaft be confidered, 
jt appears to be pretty regularly indented. 
The headlands of Tres Puntas, Codera, 
S. Roman, and Chichibacoa, on the weft, 
from Cabo de la Vela, form a row of pro- 
montories, the wetlern of which runs more 
to the north than the eaftern. To the 
windward cf each of thefe capes a creek 
Li has 
