SOUTHERN PACIFIC LINES 211 
Some of the Apache and overlying limestones are exposed in cuts 
of the railroad 6 miles west of San Carlos. To the southwest are the 
Pinal Mountains (pee-nahl’), consisting of granite and schist and 
culminating in Pinal Peak (elevation 7,850 feet). 
Passing out of the Indian reservation about 12 miles west of San 
Carlos, the railroad crosses the gravel-filled divide between the Gila 
and Salt River drainage basins and descends a short 
._..._ distance to Globe. 
Population 7,187. The old mining town of Globe owes its existence 
New Orleans 1,510 and sustenance mainly to the Old Dominion copper 
mine, the workings of which extend far under the 
hills on the north side of the valley, in the northern part of the town. 
This mine has been in operation since 1877, producing a large amount 
of copper, much of it from rich ore that has been smelted, as is indi- 
cated by the great terrace of black slag near the mine. The ore is 
Globe. 
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FIGURE 52.—Secti th ter of Hayes Mountain, southwest of San Carlos, Ariz. 
in rocks of the Apache group, especially the Mescal limestone, which 
are invaded by large dikes and sills of diabase intruded in molten 
condition in pre-Cambrian time. Lying unconformably above the 
Apache rocks are sandstone of Cambrian age, limestone of Devonian 
and Carboniferous age, and a capping of dacite, a light-gray massive 
volcanic rock of Tertiary age that is conspicuous on the slopes near 
the mine. The area is traversed by many faults. The mine is very 
wet; in 1928 it was necessary to pump 5,000,000 gallons a day. 
Part of this water is sold for use at Miami and elsewhere. There 
are smaller mines north of Globe which have yielded considerable 
copper. Globe was established in 1876 and named from a nearby 
mining claim. (See figs. 53, 54.) 
Globe is in a region of great archeologic interest, for many remains 
of prehistoric structures and implements have been found here, and 
on the Healy terrace, on the edge of the city, an old dwelling has been 
uncovered. 
50 According to the U. S. Bureau of | and silver. Most of the ore is now 
Mines the production of ore at this | mined from 2,400 to 2,600 feet below 
mine to 1929 was 415,890 tons, aver- | the surface. According to the Mines 
aging 2.65 per cent of copper and | Handbook for 1931 this mine paid 
yielding about 18,943,000 pounds of | dividends of $14,405,260 from 1905 to 
copper, together with considerable gold | 1918 and $2,477,750 from 1919 to 1929. 
