142 
The various forms of the surface are pointed 
out, such as the Great Valley of Tennessee and 
the portions of the mountain district and the 
Cumberland Plateau, by which it is bounded, 
and the relation between these forms and the 
underlying rocks is made clear. 
Under the heading ‘Stratigraphy,’ the geo- 
logic history of the Appalachian province is 
presented in outline, and the local rock groups 
are fully described in regard to composition, 
thickness, location, varieties and mode of de- 
position. The formations, thirty-three in num- 
ber, range in age from Cambrian to Carbonifer- 
ous, far the greater part being Cambrian and 
Silurian. The mountain district is chiefly un- 
derlain by the Ocoee series, whose age is doubt- 
ful. Rocks of Carboniferous and Devonian 
age occupy two small belts on either side of the 
Great Valley, and Silurian and Cambrian strata 
are repeated in narrow belts along the Great 
Valley. Limestones, shales and interbedded 
sandstones make up the Silurian and Cambrian 
strata ; sandstones and shales, with coal seams 
and a limestone near the base, constitute the 
Carboniferous, and the Ocoee rocks are con- 
glomerate, sandstone, slate and limestone. 
The details of the strata are graphically re- 
presented in the columnar section. The differ- 
ent manner in which the formations decay is 
discussed, and the dependence of the residual 
soils and surface forms on the nature of the 
underlying rock. Great changes occur in the 
formations of this region, and the Knox dolo- 
mite is the only one which is uniform through- 
out. The direction of change was exactly re- 
versed between Cambrian and Silurian time. 
In the discussion of ‘structure,’ after a gen- 
eral statement of the broader features. of the 
province, two methods are described in which 
the strata of this quadrangle were deformed. 
Of these the extreme Appalachian folding, ac- 
companied by faulting and metamorphism, is by 
far the most prominent and is about equally 
developed throughout the quadrangle. Faults, 
especially, are most strikingly exhibited here. 
Deformation by vertical uplift also is exhib- 
ited, but only in comparison with broad sur- 
rounding areas. In this quadrangle the Great 
Valley is at its narrowest, on account of the 
extreme shortening in deformation. The struc- 
SCIENCE. 
(N.S. Vou. VI. No. 134. 
ture sections illustrate the sharp folds and 
frequent faults into which the strata were 
forced. 
Heonomic products of this region are coal, 
variegated marble, red hematite, building stone, 
lime, clays, timber and slate. The outcrops of 
the formations containing these are illustrated 
on the economic sheet, together with the loca- 
tions of the mines and quarries. The iron ore 
and slate are of minor importance now; the 
coal district is a part of the great coal basin of 
Tennessee, on the same formations as the chief 
mining center of the State; and the marble 
belts are a part of the principal productive 
region for that stone. Various conditions 
affecting the value of these deposits are pointed 
out, and the associations and availability of the 
building materials and timbers are discussed. 
FOLIO 27, MORRISTOWN, TENNESSEE, 1896. 
The Morristown folio, also recently pub- 
lished, by the same author, deals with that por- 
tion of the Appalachian province which is situ- 
ated between the parallels 36° and 36° 30’ and 
the meridians 83° and 83° 30’. This area con- 
tains 963 square miles, divided between the 
counties of Greene, Cocke, Jefferson, Hamblen, 
Grainger, Claiborne, Hancock and Hawkins, all 
in Tennessee. 
Included in the folio are topographic, eco- 
nomic and geologic maps, structure and strati- 
graphic sections and five pages of descriptive 
text. 
After a description of the broader features of 
the Appalachian province, the local geography 
is analyzed. The various types of surface fea- 
tures are pointed out and their relations to the 
underlying rocks are shown. Local facts, such 
as elevations and the drainage by the tributaries 
of the Tennessee River, the Nolichucky, French 
Broad, Holston and Clinch Rivers, are detailed. 
Under the heading ‘Stratigraphy’ the geo- 
logic history of the Appalachians is presented in 
outline. This is followed by a detailed account 
of the local rock groups in regard to their loca- 
tion, composition, thickness, variations and 
mode of deposition. The soils and forms of 
surface produced by each formation are dis- 
cussed with the formations. Twenty forma- 
tions are distinguished in this quadrangle, 
