SOUTHERN PACIFIC LINES 
175 
and ascends the west slope of the wide valley. Near Forrest there are 
buttes of eastward-dipping limestone of Comanche age (Mural lime- 
stone), outliers of the large mass of Comanche strata which constitute 
the east side of the Mule Mountains.*! 
In one of these buttes a short 
distance west of Forrest is the large Paul lime quarry. The railroad 
passes around the south end of this range, which shows a few rocky 
ledges, and crosses the Espinal Plain, which is occupied by gravel and 
sand. 
At Bisbee Junction there is a branch railroad to Bisbee, 8 miles 
north, which passes the great concentrating plant of the Copper 
n Co. 
Bisbee,” a prosperous city in the Mule 
Quee 
Bisbee Junction. Mountains, is built in a most picturesque fashion in 
Elevation 4,676 feet. 
New Orleans 1,427 
small production. 
the narrow crooked canyon and along the precipitous 
slopes of Mule Gulch. It began as a lead camp with 
The rich Copper Queen ore body 
was discovered in 1878 and for a few years yielded ore averaging 23 
31 In the Mule Mountains the Co- 
manche series comprises the following 
formations: 
perce a —_ nodular shales with 
‘oss-bedded buff, tawny, and red sand- 
stone; a _ Tages = —_—— limestone 
Near 
Feet 
limestone; upper member massive 
hard gray limestone; lower member thin 
alternating wi 
“a —— a few thin layers of it 
limeston ar top 
Glance ca uestlaes ‘bodded conglomerate 
ith rather angular pebbles, chiefly schist, 
chert, and limestone of local origin (uncon- 
formably on older rocks) 75 
32 The formations at Bisbee comprise 
Pinal schist, Bolsa quartzite, Abrigo, 
lim 
believed to have been originally shales 
and arkosic sandstones, were folded 
and metamorphosed to their present 
crystalline condition in pre-Cambrian 
time. They are cut by granite and 
on 
Paleozoic formation, lying unconform- 
ably on the schist, is the Bolsa quartz- 
ite. to 500 feet thick 
and is overlain by about 750 feet of 
which Stoyanow has recently discov- 
-tura formation, shales 
ered many trilobites of Upper Cam- 
brian age. Martin limestone, 300 
to 350 feet thick, is of later Devonian 
ici De- 
sissippian is represente e 
brosa limestone, 700 feet thick, and the 
Pennsylvanian and Permian by the 
Naco limestone, about 3, 000 feet thick. 
glomerate, 25 to 500 feet; Morita for- 
mation of sandstones and shales, 1,800 
low, 650 feet; and at the top the Cin- 
and sandstones, 
1,800 feet or more. There has been 
t of the strata with con- 
basement of Pinal schist. The Lower 
Cretaceous beds were deposited on an 
unevenly eroded surface of the uplifted 
of : 
later times, 
