East Manhattan Wash Gold Project, Nevada

Overview

The East Manhattan Wash Gold Project is a low grade high tonnage placer style gold-silver deposit. This area of wash is adjacent to and possibly overlies a zone of low sulfidation epithermal gold-silver mineralization, which is believed to be source of the precious metals. The project is located in the Manhattan Mining District of Nye County, Nevada. The project is wholly owned (100%) by Riley Gold Corp, but was most recently explored by the Canadian silver, copper and gold exploration company MAX Resources Corp.

Regional Geology

Gold deposits in the Manhattan District occur along a major arcuate fracture zone on the southern margin of the Manhattan Caldera. The caldera formed 25 million years ago (Ma) during the Oligocene period. Most of the veins in the district occur within a younger E-W oriented graben formed by extensional forces, just lying within the margin of the caldera. The age of the mineralised veins is around 16 million years old. The most productive mines and prospects in the area occur along a 1 km wide zone parallel to the caldera’s marginal ring fault. Gold deposits also exist within the older underlying Cambrian-Ordovician age (542-443 Ma) sedimentary and metamorphic rocks, along the same major fault.

Project Geology

Historic production from the district has been around 1 million ounces of gold, won from placer and hard-rock mines. The majority of hard-rock workings in the area are within Tertiary age (65-1.8 Ma) volcanic rocks.

The area is located 13 km south of the Round Mountain Mine, a joint venture between Kinross Gold and Barrick Gold. The mine has produced in excess of 12 million oz ounces of gold from high tonnage low grade ore, in which the gold is disseminated throughout the rock. The average grade at Round Mountain is only 0.5 g/t gold (Au).

In 2009, MAX Resource Corp. recovered 4.9 g/t gold (Au) and 1.2 g/t silver (Ag) from a 360 kg bulk sample. Assays from 163 soil samples taken in 2010 produced values to 1.27 g/t Au.  It is believed that a volcanic rhyolite lithic tuff hosts the reasonably coarse and free gold. Argillic alteration has been observed in the sample pits. This is a form of relatively low temperature hydrothermal alteration during which clay minerals are formed. This may indicate a nearby centre of hydrothermal activity and associated gold mineralisation.

A short 2014 drill program returned disappointing results, maxing out at 13.7 m at 0.106 g/t gold. MAX concluded mineralization was a result of supergene processes, and was restricted to the surface.

Discussion

The presence of large tonnage, low grade deposits in the area suggests East Manhattan Wash could be associated with epithermal mineralization similar to Round Mountain. The handful of holes drilled by MAX only reached a depth of a few 10’s of m. While they didn’t encounter significant mineralization, the geology of the property is not yet well understood. This seems unlikely to change anytime soon; exploration is not currently active at the site.

Further Reading

Riley Gold Corp: https://rileygoldcorp.com/ (website)

MAX Resource Press Release Reviews 

MAX Resource Corp. (Corporate Site)

Kinross Gold Corp – Round Mountain (Corporate Site)

Barrick Gold – Round Mountain (Corporate Site)