Copper Giant Group
Mineralization is bedded tabular ore bodies of secondary copper eroded from oxidized copper deposits to form clastic deposits within fanglomerate, or ground-water percolation dissolved clastic copper and later precipitated chrysocolla along favorable horizons. Slica also precipitated with copper.
Local rocks are the Locomotive Fanglomerate and the Ajo volcanics. Throughout this area small, scattered outcrops of copper mineralization, primarily chrysocolla, occur.
In the Copper Giant area, the Locomotive fanglomerate consists of many types of rock fragments in a red arkosic siltstone or sandstone matrix. The fragments are composed of monzonite, quartz monzonite, trachyte, pegmatite granite, diorite, schist and gneiss, andesite, limestone and dolomite, quartzite, and conglomerate. The Ajo volcanics interfinger with the fanglomerate, and some beds consist of a mixture of volcanic and non-volcanic fragments.
The volcanics in the area consist of andesitic breccias and tuffs, with little or no lava. The breccias consist of angular to subrounded fragments of gray to red andesite, vesicular andesite containing some amygdules filled with calcite, andesite containing phenocrysts of plagioclase 1 to 3 mm wide, and a small amount of diorite.
The mineralization at the surface is found along definite beds, mainly in the fanglomerate, and in irregular mineralized masses in the volcanics. There are 4 main zones in the fanglomerate. The largest of these can be followed for over 500 feet and varies in width from ½ to 7 feet. Another such zone, a few feet NE of the largest, can be followed for 400 feet and varies in width from ½ foot to 5 feet.
The surface showing may grade with depth to chalcocite. The ore is 152.4 meters long and 2.13 meters wide.
PD had rights to the Copper Giant up until the mid-80’s when they closed their mining facility in Ajo, Arizona known as the New Cornelia Mine due to low copper prices. The New Cornelia is a porphyry copper deposit that is associated with large mines but relatively low grades of copper. The Copper Giant property is associated with the New Cornelia porphyry deposit as it is an exotic copper deposit. An exotic copper deposit consisting of high grade copper oxides filling fractures and pore spaces within rocks and in this case the alluvium at the Ajo Mining District. They form when rain water comes in contact with sulfide ores in the porphyry; acid is generated that leaches the oxide ore putting it into solution. While in the solution the copper is cared with the water. At some point the water will encounter a basic substance like limestone. At this point the copper then comes out of solution and generally forms a high grade, acid soluble copper ore deposit typically forming chrysocolla, chalcocite, malachite, and azurite. The Copper Giant has grades that are extremely high because of the nature of the deposit. Assays from PD showed grades from 0.60% to 3.50+% AsCu. The deposit is also near surface so stripping cost will be low.
PD trench assays Highlights:
- West trench: 47' @ 0.6% Cu, 10' @ 1.33% Cu
- East trench: 75' @ 0.51% Cu, 5' @ 2.05% Cu
PD Drilling Highlights:
- Drill Hole #2 - 416 ft. (2.4' @ 3.76% Cu)
All core still exists and is located at the AZGS Core Repository in Tucson, AZ
Cornelia Group
Mineralization includes secondary copper minerals.
- Geophysics and Mag surveys indicate the presence of a large subsurface sulfide deposit in this area.
- Little Ajo Mtn Fault dipping <45 degrees, attitude of fanglomerate N. of the fault is not (as reported by Gilluly) similar to that S. of the Ajo Mine
- Water well in sec.2; bedrock at 1100 ft.