354 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1902. [bull.* 
Specimen No. 1, known at the pit as brown cap sand, contains 5.0C 
per cent of bitumen, or 1.73 per cent of petrolene and 3.33 per cent of 
asphaltene. It is essentially a sandstone, since it contains 92.40 pei 
cent silica. 
Specimen No. 2 is a black sand rock containing 16.53 per cent bitu- 
men, of which 14.13 per cent is petrolene and 2.40 per cent asphaltene. 
The percentage of silica in this rock is 81.20. 
Specimen No. 3, a grayish rock exhibiting banding, contains 0.(38 
per cent of bitumen, 69.15 per cent of silica, and 20.35 per cent of 
carbonate of lime. 
Specimen No. 4 is a black, gummy rock carrying 8.86 per cent of 
bitumen, 7!). 50 per cent of silica, and 0.14 per cent of carbonate of 
lime. The bitumen determined as petrolene amounts to 6.61 per cent, 
and the asphaltene to 2.25 per cent. 
Specimen No. 5, which is a calcareous sandstone, contains 4.58 per 
cent bitumen, which equals 3.46 per cent petrolene and 1.12 per cent 
asphaltene. The carbonate of lime in this specimen amounts to 46 
per cent, and the silica to 49.42 per cent. At the pit this rock is known 
as limestone. 
No doubt specimens taken from these classes of rock would vary 
from place to place in the pit. The analyses, however, probably rep- 
resent fairly the materials obtainable. 
Like similar deposits in other regions, there can be little doubt that 
this asphalt um is merely the residuum from petroleum, the lighter 
and more volatile portions of which have escaped by evaporation. It 
lias also doubtless Undergone certain chemical changes, chiefly oxida- 
tion, during its long exposure to atmospheric conditions. 
By means of test borings the asphaltuni bed lias been proved to 
extend over a number of acres, under a cover sufficiently thin to per- 
mit profitable mining by stripping. At the time the deposit- was last 
visited, in November, L902, a pit about 100 feet in diameter had been 
opened and a tramway built to the railroad, about- half a mile distant. 
It is proposed to use the materials in such proportions as will pro- 
duce a good paving mixture. The occurrence of the limestone with 
the sandstone makes this possible without the addition of material 
from other sources. A practical test will be made at Little Rock, 
where a contract has been obtained for paving certain streets. 
The utilization of this deposit is a technical matter which can not 
be entered upon here. Its chief value will doubtless be as a paving 
material. As stated above, some portions of the bed form a natural 
paving mixture, which hardens on exposure to the sun, and, so far as 
could be judged, would be fully as durable as the ordinary artificial 
mixtures made from Trinidad asphalt. Other portions are too rich 
to be used in a natural state. Tests of these portions in the prepara- 
tion of a paving mixture have been made by the St. Louis Testing and 
Sampling Works, with excellent results. 
