The New Standard Copper Project is located in the Cienega District of La Paz County, Arizona. The project lies 19km southeast of Parker, and is accessible by paved roads, followed by a few kilometres on unsealed roads. Substantial irrigation channels and power lines lie within one kilometre of the property’s eastern boundary.
The Project comprises 6 lode claims covering 120 contiguous acres, in a district of considerable old workings dating back to the 19th century. Historic workings provide evidence of copper mineralisation over a 1.5 kilometre extent.
It appears from desktop studies of historical reports that mining and processing continued to approximately 1922. No modern exploration has been undertaken in the area and EV Resources intends to commence a programme of mapping, sampling, geophysics before moving rapidly to drill testing.
New Standard mineralisation is interpreted to be what is termed detachment fault style, a style of copper mineralisation prolific in West-Central Arizona.
Mineralisation related to detachment faulting has only recently been recognized as a distinct deposit type, even though such deposits have been mined since the 1860s. These deposits have characteristic mineral assemblages, alteration patterns, ore fluid types, and structural controls that differ considerably from those of other deposit types found in the Basin and Range province of the Western United States. However, detachment-fault-related mineralisation is not widely known, and most of the detailed studies have appeared as publications of the Arizona Geological Survey and the Arizona Geological Society.
Detachment faults are low-angle (up to 30°) normal faults of regional extent that have accommodated significant regional extension by upward movement of the footwall (lower-plate) producing horizontal displacements on the order of tens of kilometres. Common features of these faults are supracrustal rocks in the upper-plate on top of lower-plate rocks that were once at middle and lower crustal depths, mylonitisation in lower-plate rocks that are cut by the brittle detachment fault, and listric and planar normal faults bounding half-graben basins in the upper plate.
The detachment fault and structurally higher normal faults locally host massive replacements, stockworks, and veins of iron and copper oxides with locally abundant sulphides, veins of barite and (or) fluorite, and veins of manganese oxides.
This mineralisation is termed detachment fault related, not simply because it is strongly controlled by detachment-fault structures, but also because it is apparently related to the formation of detachment faults themselves. Deposits are controlled by structures formed during detachment faulting. These include the lowangle, detachment-fault system, high-angle faults in the lower-plate just below the detachment fault, and low- to high-angle normal faults in the upper-plate.
Deposits are often brecciated or deformed by movement along or above the detachment fault. Chlorite-epidote-calcite alteration occurs along and below the detachment fault. These altered zones sometimes contain base metal sulphides and barite.
Most mineralisation consists of iron and copper oxides, principally specular to earthy hematite and chrysocolla. Common gangue minerals are chalcedonic to amethystine quartz, ferrous to manganiferous calcite, barite, fluorite and manganese oxides. Distal barite-fluorite veins consist of variable proportions of barite, fluorite, and manganese oxides. Common gangue minerals are quartz.