Page 73 - The Geology and Ore Deposits of Sierra County, New Mexico - Bulletin 10

72 GEOLOGY AND ORE DEPOSITS OF SIERRA CO., N. M.
drilled with a churn-drill rig to a maximum depth of 260 feet at Hardcastle Creek, north of Taylor Creek and northeast of Squaw Creek. The samples taken ranged in grade from zero to 2.0 per cent tin, with an average grade of about 0.15 per cent. It is also stated that at a later date one or more diamond-drill holes were drilled by other interests, but the results were essentially the
sameP. roduction from the district has been limited to a few hun- dred pounds of specimens and crude concentrates, and this material has been used only for display or for testing.
DEVELOPMENT
Development in the district has been confined entirely to shallow working, which consists of open cuts, tunnels, pits and shafts. Most of these workings are close to the level of the can- yon floors, but some are located along the tops of the cliffs in the rhyolite flow rock.
FUTURE POSSIBILITIES
The tin-bearing veinlets that have been exposed so far are all of small size, discontinuous and of small tin content. Should an area be found containing many closely spaced veinlets, with the cassiterite disseminated for short distances into the wall rock, a fairly large low-grade ore body might be developed. The separation of the cassiterite from hematite, however, might offer a serious handicap to efficient and cheap treatment.
There has not been a great deal of erosion to supply the gravels with tin. The gravels are limited to narrow channels of shallow depth, large boulders in the gravel will present an oper- ating problem, and the development of sufficient water will be costly except in Taylor and lower Beaver creeks.
BLACK RANGE AND APACHE (CHLORIDE) DISTRICTS
LOCATION AND AREA
The Black Range and Apache (Chloride) districts include
an area of nearly 350 square miles, extending from above the north boundary of Sierra County southward along the east slope of the Black Range for a distance of 24 miles to Monument Creek, 6 miles south of the town of Chloride. Plate IV is a gen- eral map of the district. The maximum width of the mineralized zone is 14 miles. The Black Range mining district continues northward into Catron County nearly 3 miles, while south of the line it terminates at Bear Creek, just north of the old town of Robinson, which is 8 miles south of the county line and 6 miles north of Chloride. At this point the Apache mining district be- gins and continues for 12 miles to Monument Creek. Fairview and Chloride are the principal towns in the region, being 37 and 40 miles respectively from Hot Springs, the nearest source of