6 posts in this topic
By Steve Herschbach
From Placer Gold Deposits of Arizona, USGS Bulletin 1355, By Maureen G. Johnson 1972
HISTORY OF PLACER MINING IN ARIZONA
Arizona's placer-mining industry began in 1774, when Padre Manuel Lopez reportedly directed Papago Indians in mining the gold bearing gravels along the flanks of the Quijotoa Mountains, Pima County. Placer mining was active in that region from 1774 to 1849, when the discovery of gold in California apparently attracted many of the Mexican miners who worked the gravels (Stephens, 1884). Arizona was then part of Mexico, and little is known of the placer mining that probably was carried on in various parts of southern Arizona.
Placers were probably worked in the Oro Blanco district, Santa Cruz County, and the Arivaca district, Pima County. The part of Arizona north of the Gila River was ceded to the United States in 1848, and the part of Arizona south of the Gila River, where most of the early placer mining occurred, was purchased in 1853. Placers were discovered in the 1850's in the Bagdad area, Yavapai County, and Chemuehuevis Mountains, Mohave County; but it was not until 1858, when placers were discovered by Colonel Jacob Snively at the north end of the Gila Mountains, Yuma County, that the first placer-mining rush in Arizona was precipitated. The early years of the 1860's saw the discovery of the famous placers at La Paz, Yuma County, and Rich Hill and Lynx Creek, Yavapai County; many smaller and less famous placer fields were discovered at that time.
In the 1860's, Arizona was a relatively isolated and underpopulated territory, fraught with communication and travel difficulties, and beset by Indian problems. Placer mining was actively pursued throughout the territory, and some rich lode-gold mines were discovered and worked; but real news of Arizona mining was slow to filter out from the territory to the more populated areas in California and the East. The period from 1860 to 1880 is reported as the most active and productive period in placer mining, but because of poor communications, there is very little reliable information or production record.
By 1900 most placer areas had been discovered, and many were nearly worked out. Placer mining continued intermittently during the early years of the 1900's. Many attempts were made in various parts of the State to mine placer gravels by drywashing machines, but it was not until the economic impetus of the depression that placer mining became active again in Arizona. During the years 1930-38, 95 different districts were credited with placer gold production, but many of these districts produced only a few ounces.
After the boom of the 1930's, the war years of the 1940's were a setback to gold mining activity. War Production Board Order L-208 greatly restricted the development of gold mines; prospecting for and mining metals essential to the war effort was deemed more important than mining gold. Even more important, however, the economy of the 1940's encouraged work in offices, factories, and war industries for those not in military service, and as a result, many miners and prospectors left the gold fields and never returned.
After 1942, placer production never again reached the heights of the 1930's or the peak production of the 1860's to 1880's.
GOLD PRODUCTION FROM PLACER DEPOSITS
The U.S. Bureau of Mines (1967, p. 15) cites 500,000 troy ounces of placer gold produced in Arizona from 1792 to 1964. I estimate that placer gold production was at least 564,052 ounces. Districts of largest placer production were the Lynx Creek, Big Bug, and Weaver (Rich Hill) districts (Yavapai County), the Gila City (Dome), and La Paz district (Yuma County), and the Greaterville district (Pima County), all with estimated placer production of more than 25,000 ounces.
Arizona has many small placer-mining districts (Plate 1) from which only a few ounces of gold has been recovered, mostly during the depression years of the 1930's. For most of these districts, little information other than production has been found. Major lode-gold districts in the State, except for the Bradshaw Mountains in Yavapai County, have had very little placer gold production.
Most of the placer gold produced in the State of Arizona was recovered by tedious work on a small scale by individuals who used rockers, pans, sluices, and dry concentrators. In only a few districts have large-scale placer-mining operations been successful, although many attempts were made to use large dry-concentrating machines.
The most successful large-scale operations have been in the Lynx Creek and the Big Bug districts, Yavapai County, where the presence of adequate supplies of water enabled large dredges to mine the gold bearing gravels. Among the largest and most profitable large-scale dry concentrating operations were those in the San Domingo Wash district,
Maricopa County, in the Plomosa district, and at La Cholla placers, Yuma County; at Copper Basin, Yavapai County, the gravel was hauled to a central washing plant where wet methods of recovery were used. The total amount of placer gold recovered yearly in Arizona from 1900 to 1968 is graphed in figure 1, which also shows major contributors to the peak production.
The ultimate source of detrital gold in placer deposits is, for the most part, gold-bearing lode deposits, which in Arizona are represented by veins in faults, fissures, and shear zones of various sizes.
Most of the placer gold found in Arizona was derived from systems of small gold-quartz veinlets and stringers scattered throughout the bedrock of the adjacent mountain ranges; in only a few localities was the gold in large placer deposits derived from vein systems of sufficient size to encourage lode mining on a large scale. Small placers commonly occur near large gold lodes, but are generally not economic.
The most productive gold veins are those formed during Laramide time, which occur in rocks of Precambrian to Laramide (Late Cretaceous and early Tertiary) age. Much gold has been recovered as a byproduct from copper and other base-metal ores. Since 1941 the large copper mines have been predominant in the production of lode gold (Wilson, 1962).
Got out Friday, and decided to use the good ol Boat Anchor 19 " coil on the ZED. After finding the Specimen Gold, and into it 2 hours, my Bungee broke, and I had to go to my backup bungee, and also switched back to the 14". I was using the High Yield Mode with the 19" coil, since the soils here are not to bad, and I seem to get a little more depth using the 19" with High Yield.
Got a text yesterday from my buddy Chris, who said dude, get your , and lets get out there !!!! ( Well something like that , hehe !!! ) . I told him I can only hunt a half day, even though today was just a great day for a full day of hunting today, darn it !!!! Ended up finding almost 10 grams today.. :) . The large piece was a little more than a foot down, and just made a break in the threshold, I kicked some dirt out of the way, and it made the nice mellow weewoo sound, and I was like . Some digging in the side of a wash a little more than a foot down, and got a ..... maybe a foot away I found another small nugget right on top of the ground, and found another small piece in another wash.
I also brought home a new pet, and the good ol U.S. deserts give them away for free, as you can see in the picture, he is enjoying his new home.... I have been bringing baby dinosaurs home in the backyard for years, but they never grow up , they just make babies in my back yard and eat the spiders...
By Steve Herschbach
Originally a silent film by the U.S. Smelting and Mining Co. from 1949, station KUAC of Fairbanks, Alaska added a sound track and narration to explain the process and history of mining gold in Alaska's rugged conditions.
By Rick Watkins
Going to finally get a gold trip in last week of Oct, hopefully, i heard that area got some good rains recently,just wondering what you guys that have been near winnemucca think about bringing my drywasher ,is the ground still too damp. I heard they had 2 storms that dumped 1/2 of rain each one.