360 J. M. Safford on the Cretaceous 
Art. XXXIII—On the Cretaceous and Superior Formations of 
West Tennessee ; by Jas. M. SaFForp, Lebanon, Tenn, 
In this article I propose to enumerate and describe briefly, so 
far as my examinations will permit, the Cretaceous and higher 
formations of West Tennessee. But before commencing with 
the lowest in order, it will be well to notice first the formation 
of gravel that is so common and conspicuous in the Western Val- 
ley of the Tennessee river,’ and that rests upon all the formations 
occurring in this region excepting the alluvium of the bottoms 
The Western Valley Gravel.—This formation is, by no means, 
continuous over the whole area to which it belongs. It occurs 
in patches, or detached beds, depending much, in this respect, 
upon the nature of the surface on which it rests, and upon the ex- 
tent to which it has been denuded. The beds, however, often 
cover locally large areas, the observer travelling upon them with- 
out a break for many miles. Their thickness is not great, rarely 
exceeding fifty or sixty feet, and being generally much less. 
This gravel was doubtless deposited after the valley had re- 
ceived, for the most part, its present general form. _ Its beds are 
found upon the bluffs of the river, upon the uplands back of the 
bottoms and upon comparatively high ridges, being always the 
uppermost formation. It is often seen as far back as eight ot 
ten miles from the river on both sides. On the eastern side it 
extends farther, and frequently caps the very high ridges of this 
part of the State, some of which are 800 feet above the sea. In 
this direction it extends, at some points, a few miles beyond the 
he worn pebbles are sometimes locally mingled with angular 
cherty fragments; but in such cases the beds are in the vicinity 
of Paleozoic rocks, the known source of the angular chert. Not 
unfrequently masses of the gravel may be seen cemented, usually 
by oxyd of iron, into heavy blocks of coarse conglomerate. 4 
some of the iron-ore banks within the limits of this formation, 
we find sections presenting mingled masses of worn pebbles, am 
gular chert, and heats in irregular fragments and in “ pols 
the masses occasionally cemented into solid blocks. 
* Or simply the Wester : i i mparatively narrow 
and broken valley slaoegie-windh ts ‘ocean pe <i poles 0 Alabama‘? 
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