GOLD RIVERS
1 COLORADO RIVER . Gold was first discovered on the Arizona section of the Colorado River in 1862 by Pauline Weaver,
2 LYNX CREEK . Lynx Creek is located in the Prescott National Forest in central Arizona.
3 THE HASSAYAMPA RIVER .
4 THE AGUA FRIA RIVER .
5 GILA RIVER . Gravels have been dry washed from the Gila River to about 4 miles north of McPhaul Bridge.
6 SAN FRANCISCO RIVER .
7 MORENCI GULCH . tributary of San Francisco River .
8 SANTA CRUZ RIVER .
9 SANTA MARIA RIVER . North of Hillside Station near the Santa Maria River was the Mammoth or Hubbard Mine .
10 LAKE PLEASANT .
MINING SITE
1 LA PAZ MINING DISTRICT . Near Colorado River
2 VULTURE MINE . The Vulture Mine in Maricopa County of Arizona as the most productive gold mine in the state.
3 LITTLE SAN DOMINGO PLACERS . These placers are just about an hour away from Phoenix. There are lots of little dry washes.
4 OATMAN . Oatman is an old mining town located in the Black Mountains of Mohave County.
5 BRADSHAW MOUNTAINS . The Bradshaw Mountains are located in Yavapai County.
6 QUARTZSITE .
7 WICKENBURG MOUNTAINS .
8 BIGHORN MOUNTAINS .
9 BLACK CANYON CITY .
10 HUMBUNG .
11 GOLD BASIN . Mohave District .
12 KINGMAN .. Mohave District .
13 EUREKA . Yavapai District .
14 GRANITE CREEK . Yavapai District .
15 BIG BUG CREEK . Yavapai District .
16 KIRKLAND . Yavapai District .
17 VULTURE . Maricopa district .
18 ELLSWORTH . La Paz District .
19 PLOMOSA . La Paz District .
20 KOFA . Yuma District .
21 CASTEL DOME . Yuma District .
22 TRIGO . Yuma District .
23 CABABI . Piwa District .
24 SIERRITA MOUNTAINS . Piwa District .
25 NOGALES . Santa Cruz District .
26 PATAGONIA . Santa Cruz District .
27 DOS CABEZAS . Chochise District .
28 ALDER CANYON . Santa Cruz District .
29 OLD HAT . Pinal District .
30 PAYSON . Gila District .
ORIGIN OF PLACER GOLD
The gold in placer deposits in Arizona is derived from veins and other hardrock deposits dis-tributed through the bedrock of select mountain ranges. In a process occurring at various times throughout Arizona’s geologic past, but prin-cipally during the Precambrian, Laramide, and mid-Tertiary time, mineralized fluids ascended along cracks and fissures in the existing rocks, precipitating gold and other mineral constituents into veins or other bodies as lode deposits. It is predominantly these lode deposits that are the source of placer gold in Arizona.
Gold must be freed from its host rock before it can be concentrated as placer gold. The disintegration of the rocks in which the gold veins are confined is a slow process, in human terms, accomplished by uplift of the area, erosion, and weathering. Wind, rain, frost, chemical action, earth move-ment, and changes in temperature are the agents in this process. Gold, resistant to weathering, is liberated as the surrounding rock is reduced to gravel, sand, silt, and clay.
Running water is the dominant agent in transport-ing and concentrating placer gold once the native gold has been freed from the bedrock source. Placer deposit formation most often takes place during times of flood.
Occasionally placer deposits are formed at the site of the original lode occurrence as eluvial deposits, but more often the gold particles are transported, concentrated, and deposited by the moving water of streams and rivers into alluvial deposits. Un-derground, or buried placer deposits, recovered by driftmining, occur as the result of sediments or volcanic flows covering and preserving placer deposits.
There is rarely a fixed relation between the rich-ness of a placer deposit and the richness of the original lode deposit. Some highly productive placers have no known “mother-lode”, while some rich lode districts have formed no sig-nificant placer deposits. However, even though there is not ordinarily a high relationship between specific lode deposits and specific placer deposits, most areas have a high correlation be-tween lode· gold production and placer gold production.
