The Arizona sentinel., 1900-10-03
CASTLE DOME DISTRICT.

or Archean.
 CASTLE DOME DISTRICT.
 The veins of the Castle Dome district may be said to have been rediscovered in IS6S for it was evident that they had been anciently worked, as already stated in the historical introduction. The metal had been taken out from many of the veins b. the ancient miners down to a depth of from to l5 feet and in continuous lines of trenches, in some places for 50 to 100 feet or more. These old workings were found to be safe guides to good metal bearing ground @ short distance deeper. Well worn trails leading of from these pits to the banks of the Gila river. some IS miles distant, and the ruins there of some rude smelling furnaces, indicate that the ores were carried to the Gila, probably on the backs of Indians, and that they were smelted there whether by the Aztecs or the early-arriving Spanish explorer is not known. Since 1863 these mines have been worked almost continuously, and are now yielding silver-lead ore of most excellent quality, which is shipped to San Francisco. The claims were worked by the prospectors without capital until October, 1870. Up to January 1, 1892, there had not been | an investment of over $500 in building or per manent improvements. The climate is such | that men can work the year round without no more protection than is afforded by brush huts or tents.
 1 The veins crop out on a rolling plain or mesa at the base of the Castle Dome range very rugged and picturesque group of mountains trending northwest and southeast, rising near the center to the remarkable domeshaped sum- init with precipitous sides, looking like huge round castle or1building with dome. It is a noted landmark, being visible from great dis tance in all directions. It was originally called Capitol Dome" by the officers at Fort Yuma in 1858, from the fancied resemblance to the dome of the capitol at Washington. This mountain range, being but sparingly watered, has never ! been convenient to prospect and very little is yet known of its structure or mineral value. The mines are usually reached from Yuma by driving to Gila City and thence to the mine from Is to IS miles east and inland from the river. The claims are numerous. Some have been patented and worked to a depth of 800 feet or more. The veins are re- Elarl1ably regular and well formed. The ore is galena, carrying about 30 ounces of silver to each ton The veins trend in a general northwest and southeast course and are nearly vertical. The outcrops are in dicated by outlying masses and weather worn crystals of hourspar. which is the chief veinstone. Calcite and gypsum are also found and in some of the veins there is a vein stone of quartz dispersed in sheets or combs along the walls or in distinct sheets in the center. Manganese spar and barite are also as- sociated in layers. The thickness or power of these veins is usually from to feet, sometimes from g to 12 feet, wide. There are veins also only few inches in width. In general the veins are well filled with ore. This ore occurs in sheets or punches scattered through the vein- stone and commonly known among the miners as ball metal. h one mine in the district mass of nearly solid ore feet thick was found
 At or near the water level, where the galenite has decomposed, both carbonate and sulphate of lead are found associated with pale-green f1uorite and an abundance of crystallized yellow wulfenite, another occurrence giving evidence of the presence of molybdenum in galenite.
 The rocks Of the district are compact fine grained mica and clay states standing nearly on edge and traverSed by numerous dikes or intru- sive masses of a chocolate-colored porphyry. THE CHA VALLEY.
 The Gila valley extends from the Gila canyon near the junction of the San Pedro river, west erly to the east bank of the Colorado, distance
 
 it situated in the county of Yuma, known as the Lower Gila valley, is about 1O0 miles long and from to D miles wide, all of which is suscept- ible of profitable cultivation. The river from which it takes its name cuts the valley in two. Its watershed extends some 30 miles north and upward of 50 miles south of its channel, the land from either extreme inclinihg more or less rapidly toward the stream. The G+1G traVerSes a marVelCUsly fertile country, very great in extent, and spiendidly adapted to the lt.vatiOn Of nearly all the products of the tcInperaLe and semi 5ropic zones, besides many of the fruits common in the tropics. Nor is this longer a matter of idle speculation, for aourishing ranches in various portions of the valley, drawing water from several important canals, amply demonstrate the magnificent results that will ensue should the water supply be rendered permanent, eqUable and adequate through appropriate storage systems
 i This consists of a broad eXpa lSe of tillable valley land, sometimes ovcrnowed by the river, which is at times mighty uncertain, and steep range of volcanic hills coming close to the high ways for a dozen miles or so, hot. heavy, sandy. II is hardly fair to say sandy as it is really a l friable alluvial soil of grayish hue and loose 1 texture. Several ranches are passed, showing i that the Gila bottom iS cultivated With irri- 1 gauon every square mile of the GIa valley is capable of producing prolific crops of grain and Semi-tropioal frui.s wei as cotton and sugar ! in great abundanse. The river is able to fur nish all the water needed and good deal more. ] It would take no great skill in engineering and not q very large sum of money either to con struct reservoirs or lakes ill which to receive and store the overflow, There are natural basins or dry lakes into which by simple means the water cOuld be conveyed.
 The lands situated in and about the Gila val ley may conveniently be classified as follows: First, the bottom or overflow lands; 2, slightly higher valleys, lands subject U 70 overflow; 3. mesas or slopug uplands; I. high but compar- 3tively level pains ,, mountains.
 The bottom lands, as well as those slightly higher, stretch along either side of the Gila and ! Colorado rivers for varying distances north and south. until they meet the more elevated mesas which rise from the valley. The bottoms lie directly along the river and are subject to inun- dafon annually ImmcdiateIy following the >Uhsidence of the waters the local Indians were in former times accrmJon3ed to plant corn. p"mpi<ius. melon, and other vegetables. These