304 CEMENT MATERIALS AND INDUSTRY. [bu 
Analyses of Tennessee marbles from the upper part of the Lenoir limestone. 
Silica ( Si< ),) . 0. 17 
Alumina (A1 2 3 ) ' - - 04 
Iron oxide ( Fe 2 3 ) - • 23 
Lime (CaO) - j 55. 47 
Magnesia (MgO) - . 30 
Sulphur ( S ) 1 
Carbon dioxide ( C0 2 ) 43. 63 
Water . 21 
0.1 
T 
.26 
55. 1 
.21 
i:;.51 
.12 
1. Knoxville, Knox County, L. G. Eakins, analyst, Bull. U. S. Geol. Survey No. 168, p. 258. 
2. Hawkins County, A. L. Colby, analyst. Eighteenth Ann. Kept. U. S. Geol. Survey, pt. 5, p. 
Ordovician limestones above the Lenoir. — Similar and occasionall 
extensive beds of crystalline and other limestones occur locally in thl 
Sevier shale. Such limestone beds are especially well developed i| 
the bands striking southwest from Knoxville to Athens. Thinner ailfl 
more earthy beds of limestone occur, though less commonly, also in 
the Athens shale. In the region between Holston and Clinch rivett 
the Lenoir limestone is generally overlain by the Moccasin limestone,'! 
a reddish argillaceous limestone several hundred feet thick. 
UPPER ORDOVICIAN LIMESTONES OF THE WESTERN PART OF THE ({REAlV'f. 
VALLEY OF EAST TENNESSEE. 
The upper Ordovician limestones of the western half of the vallej t 
are all included in a single comprehensive formation, described in pub j 
locations of this Survey as the Chickamauga limestone. This greT 
mass of rocks, aggregating from 1,200 to 2,000 feet in thickness, cor 
sists almost entirely of limestone. Locally and in certain parts of tl 
section, especially toward the top, the limestone becomes shaly, or 
ma}^ include many thin beds of shale. Though the greater part of tl 
formation may be classed as a pure limestone, it is nevertheless tru( 
that many layers contain considerable clayey matter, while a few ar(c| 
siliceous and on decomposition give rise to chert. The percentage oi' 
magnesia, however, is almost certainly always low, although analyses 
establishing the fact are wanting. Highly argillaceous limestones, 
usually mottled with red, occur in the lower half of the formation, 
especially in the Chattanooga belt. Many localities in the western 
half of the valley doubtless would afford materials for a proper mixture 
in the same quarry. 
The Chickamauga limestone contains representatives of practically 
each and all of the formations into which the Ordovician rocks oi 
