Mineralogy and Geology. ; 433 
“The color of this species of limestone is never white, but is dark, 
varying from gray to black. It is frequently nearly of a slate 
or, and is sometimes fetid, especially when two pieces are rubbed 
together. * * *. 
ore at Wilcox’s Old Furnace ; and that traces of it were found to the 
distance of seven or eight miles south of Deep River; but I cannot 
learn that any one has discovered it, except in detached nodular 
at 
' Works on Deep River. It consists of iron mixed with a large quantity 
of clay, but is so easily quarried and broken up as to become in many 
stances a profitable ore. * * * 
“*To sum up what has been said, it appears that the district of coun- 
try which contains what I have called the freestone and coal formation 
of Orange and Chatham, affords materials for various purposes of arch- 
tecture, for millstones, for grindstones and whetstones ; that it em- 
braces of bituminous coal of unknown extent 3 and that, both 
fi 
inciples, hopes may reasonably be entertained that the same region 
will yield a supply of limestone and iron ore, and possibly of sali and 
ani”? : 
6. Preliminary Geological Report of the U. S. Pacific Railroad 
Survey, under the command of Lieut. R. S. Williamson, Corps of Top. 
Eng., 1853; by W. P. Buaxs, Geologist of the Survey.—This Pre- 
liminary Report is to be followed by a detailed account of the regions 
examined, and we defer an extended notice till the latter appears. Part 
of the facts have already been published in this Journal. We cite some 
observations on Bitumen Springs,—p. 68. It is an interesting fact, 
which I believe is not generaily known, that there are numerous places 
in the Coast Mountains, south of San Francisco, where bitumen exudes 
m the ground, and spreads in great quantity over the surface. These 
Places are known as Tar Springs, and are most numerous in the vicin- 
ity-of Los Angeles. It is also common to meet with large quantities 
of this material floating on the Pacific, west of Los Angeles, and nerth- 
Ward towards Point Conception. I have seen it, when, passing this point, 
floating about in large black sheets and masses. They are probably 
the product of submarine springs; or they may be floated down by 
Small streams from the interior.* 
Some of the springs that I examined near Los Angeles were 
nothing more than overflows of bitumen or asphalt from a small 
aperture, around which it had spread out so as to cover a circular 
i 
ete mineral oil, iving to the surface the beautiful prismatic hues that are 
Produced when oil is poured on water. . 
Skconp Szems, Vol, XIX, No. 57.—May 1855. 55 
