TililESTOHE OF CUMASACOA. 
391 
plains (llanos), steppes, and deserts, have not that nniform 
tertiary I'ormatinn 'which has been too generally sup- 
posed. Do the fine pieces of riband-jasper, or Egyptian 
pebbles, ■which M. Bonpland picked up in the savannahs ot 
Barcelona (near Curataquiche), belong to the sandstone of 
the Llanos of Calabozo, or to a stratum superposed on that 
sandstone ? Tlie former of these suppositions would ap- 
proach, according to the analogy of the observations made 
by M. lloziere iu Egypt, the sandstone of Calabozo, or 
tertiary nagelfluhe. 
VII. EoiniATrojf of the Compact Limestone op 
C uMAXACOA.— A bluish-grey compact limestone, almost 
destitute of petrifactions, and frequently intersected by small 
veins of carburetted lime, forms mountains with very abrupt 
ridges. These layers have the same direction and the same 
inclination as tlie' mica-slate of Araya. Where the ilauk 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 ot 
tlie 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-ciystal. As 
subordinate layers, it contains (1) numerous strata ot car- 
buretted and slaty marl, with pyrites ; (2) quartzose sand- 
stone, alternating with very thin strata ot clayey_ slate ; 
(3) gypsum with sulphur, near G uirc, in the Golfo 1 riste, on 
the const of Faria. A s I did not examine on the spot the 
position of this yellowish-white fine-grained 
cannot determine with any certainty its relative age. _ _ 
The only pctriiactions of shells which I iound in tins 
limestone ‘formation consist of a heap of turbimtes and 
trochites, on the flank of Turlmiquiri, at more than b8tl . 
the limestone with nummulites, of Siwa. The primitive rocks frora 
which tlie fine-grained marble was believed to be extracted, 'f mety be 
deception in its granular appearance, are far distant from the Oasis of 
• This sandstone contains springs. In general it only covers the 
limestone of Cumanacoa bat it appeared to me to be sometimes en- 
dosed. 
