THE 
AMERICAN GEOLOGIST. 
Vol. XVIII. SEPTEMBER, 1896. No. 3. 
THE SO-CALLED SOCORRO TRIPOLI. 
C. L. Herrick, Granville, O. 
(Plates IV and V.) 
In several localities in the United States there are known 
beds of what is called tripoli or " American tripoli." Notable 
among these are deposits at Seneca, Newton county, in south- 
western Missouri. According to 0. H. Hovey* the Newton 
deposit is known to underly between eighty and one hundred 
acres, in an elliptical area, with a thickness of from ten to 
twenty-five feet. It is ever^^where underlaid by stilf red clay, 
seams of which penetrate the tripoli in various directions. 
Attention is called to this bed because it, like the bed under 
consideration, is not a true tripoli, i. e.,it is not an infusorial 
or diatomaceous earth, but of mechanical or chemical origin. 
It is also interesting on account of certain conflicting theo- 
ries as to its origin. Thus Hovey concludes that the tripoli 
is derived from the flint or rather the chert of the country 
rock — a cherty lower Carboniferous limestone — by some pro- 
cess of decomposition which has left behind a very fine grained 
porous material. No details of the process of such decompo- 
sition have been suggested so far as known to the writer. 
The tripoli has been analyzed b}^ W. H. Seamon, now direc- 
tor of the School of Mines at Socorro, with the following 
results : 
^Scientific American Suppl., Juue 28, 1894. 
