THE EL PASO TIN DEPOSITS. 
By W. H. Weed. 
LOCATION OF DEPOSITS. 
The El Paso tin deposits lie on the east flank of the Franklin Moun- 
tains, the southern extension of the Organ or San Andreas Range, 
about 10 miles north of the city of El Paso. The ores were discov- 
ered in 1899 and have been prospected by several open cuts and pits, 
the deepest of which is about 50 feet below the surface. The property 
belongs to Judge C. R. Moorhead, of El Paso, to whom I am indebted 
for many courtesies during my visit to the deposits. The place is dis- 
tant about 11 miles by wagon road from El Paso, 12 miles of excellent 
road across the flat mesa being succeeded by 2 miles across the foot- 
hills. The White Oaks Railroad crosses the flat 3 or 4 miles east 
of the property, and the main line of the Southern Pacific lies 10 
miles to the south. There is a good spring one-fourth of a mile from 
the ledges, but there is no large supply of water nearer than the Rio 
Grande. The mesa is underlain by water, the city of El Paso being 
supplied from driven wells sunk in the mesa gravels. The mesa is 
scantily grassed and covered with the usual desert vegetation of small 
yucca and cactus, while the mountain slopes show cedar bushes, with 
mesquite, yucca, sotol, and other arid-land plants. The mountains 
show a very regular crest of bedded rocks surmounting smoother 
basal slopes of a prevailing red-brown color dotted by green sotol 
bushes. 
GEOLOGICAL STRUCTURE AND FORMATIONS. 
The geological structure is very simple and is easily made out, as the 
mountains are not wooded, but show outcropping edges of the upturned 
limestones and bare slopes of red granite. The mountain range con- 
sists of Cambrian and other Paleozoic limestones, upturned by and 
resting upon an intrusive mass of coarse-grained granite that forms 
the central core of the range. This granite is well exposed for a dis- 
tance of 1 or 5 miles along the eastern side of the mountains, forming 
the lower half of the mountains proper, and in places extending out to 
the foothills. The crest of the range consists of steeply tilted, heavily 
bedded, dark-gray limestones dipping westward. The basal quartzites 
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