176 CEMENT MATERIALS AND INDUSTRY. [bull. 2fl 
The Coochie Brake stone is a light-yellow or bluish-yellow, coarse-grained, sandal 
limestone. It is of excellent quality for building purposes, but its value is somewhH 
impaired by the presence of small nodules of iron pyrites. These will restrict ifl 
use to situations where a good external appearance is not one of the qualities required i 
of the stone. The pyrite, if the quantity proves to be large, may destroy its vail 
altogether. The quantity of stone at this locality is large, and it is easily obtainel I 
The Bayou Chicot stone is the best for building that we have seen in the Statj I 
It is a fine-grained dark-gray limestone. Only two very small outcrops of it wea 
seen, and from these no very satisfactory ideas of the extent of the deposit could bj 
gained. In the two outcrops the dip is very great, and the cost of uncovering tb 
stone would probably be large. Borings are needed to show the depth of the deposi 
In the early history of the country lime was made at this place. The ruins of tlj | 
old limekilns are to be seen near the larger outcrop. 
Analysis of limestone from Rayborn's salt lick, Bienville Parish. n 
Si I ica ( Si0 2 ) 0. 
Alumina ( A1 2 3 ) ] 
Iron oxide (Fe 2 O s ) - I L 
Lime (CaO) 54. 
Magnesia (MgO) 
Sulphur trioxide ( S0 3 ) 
Carbon dioxide (C0 2 ) 44. 
Tertiary limestones. — The concretions of limestone in the Tertiary beds are often 
large size and have been used locally for the foundations of houses. At Shrevep 
large calcareous concretions are crushed and used on the streets and in concrl 
work. Hopkins reports a place 5 miles from Natchitoches, called the Kiln] 
where large concretions have been burned for lime. 
At Rocky Spring Church lime was burned from a little outcrop of Tertiary li 
stone for the masonry of Fort Jessup. 
PORTLAND-CEMENT RESOURCES OF MAINE. 
Numerous more or less extensive limestone beds are known 
occur in various parts of Maine, but few of these will be worth c 
sidering as possible sources of Portland-cement materials. Most 
the outcrops are located far from fuel supply and cement markets 
and the transportation question is particularly serious in a State bavin: 
so low a railroad mileage as Maine. Geologic mapping has not pro 
gressed sufficiently to give even a fairly accurate map of the limestonj | 
of the State, and few satisfactory analyses are available. It is prac ' 
tically certain, however, that the only limestones on which a Portland 
cement industiy can be based, under present conditions, are thoj i 
which outcrop along or near the Altantic coast line. 
As a source of Portland-cement material, it seems probable th 
some of the Limestones which are now so extensively utilized for li 
burning in the neighborhood of Rockland, Rockport, and Union, 
Knox County, might prove available. These limestone deposits a 
of comparative!}' large size, and are located on or near deep wate 
« Bull. IL S. Geol. Survey No. 188, p. 258; analysis by R. B. Riggs. 
H 
