The deposits at Marigold have been described as distal disseminated silver-gold deposits. Such deposits are disseminated equivalents of polymetallic vein deposits, characterized by a geochemical signature that includes silver, gold, lead, manganese, zinc, copper, antimony, arsenic, mercury and tellurium. Typically, they contain substantially more silver relative to gold than other types of disseminated gold deposits and may feature supergene enrichment of silver if significantly oxidized. In Nevada, distal disseminated silvergold deposits are proximal to Jurassic, Cretaceous, and mid-Tertiary granitoid intrusions. A fundamental requirement of the distal disseminated silver- gold model necessitates a genetic link between silver-gold mineralization and causative intrusions; however, no such relationship has been conclusively demonstrated at Marigold.

A Carlin-type gold deposit is a unique type of disseminated, sedimentary rock-hosted gold deposit. The genesis of Carlin-type gold deposits is currently not well understood. In Nevada, Carlin-type gold deposits occur along several main mineral trends, including the Carlin trend and Battle Mountain-Eureka trend, and are primarily hosted by silty carbonate rocks. Gold occurs in arsenian pyrite rims on pyrite grains and is associated with arsenic, sulphur, antimony, mercury and thallium. Even though the genesis of Carlin-type gold deposits remains enigmatic, there is consensus that all Carlin-type gold deposits in Nevada formed during the Eocene epoch.

Distal disseminated silver-gold deposits may share similarities with Carlin-type gold deposits, including ore body morphology, structural setting and alteration styles, but drastically differ with respect to alteration zonation, geochemical signature, hypogene mineralogy and endowment. Distal disseminated silver-gold deposits show a more definitive magmatic signature than Carlin-type gold deposits that includes zoning of alteration relative to felsic hypabyssal intrusions, base metal enrichment, significantly higher silver-to-gold ratios, and distinctive hypogene ore mineralogy (e.g., base metal sulfides, native gold and silver, electrum, silver sulfides and silver sulfosalts), and are typically much smaller in terms of gold endowment. Recent work suggests that the gold deposits at Marigold are best classified as Carlin-type gold deposits, based on many similarities with the Carlin-type gold deposits model and a lack of evidence for causative hypabyssal intrusions.

Marigold is located in the Battle Mountain mining district on the northern end of the Battle Mountain-Eureka trend, a conspicuous lineament of sedimentary rock-hosted gold deposits. The Battle Mountain district hosts numerous mineral occurrences, including porphyry copper-gold, porphyry copper-molybdenum, skarn, placer gold, distal disseminated silver-gold, and Carlin-type gold systems.

Four packages of Paleozoic sedimentary and metasedimentary rocks are present at Marigold. In ascending tectonostratigraphic order, these include:

- Comus Formation: The Cambro-Ordovician Comus Formation is a parautochthonous package of sedimentary and volcanic rocks, including mudstone, siltstone, limestone, and metabasalt, as well as debris flow and turbidite deposits of various provenance. The Comus Formation is differentiated from the Valmy Formation by recorded deformation history, carbonate and carbon content, rock type, and textural features.

- Valmy Formation: The Ordovician Valmy Formation is an allochthonous stack of tectonically thickened, predominantly siliciclastic sedimentary rocks. The Valmy Formation consists of quartzite, argillite, chert, and lesser metabasalt, all of which are complexly folded and faulted in the Marigold area. The top of the Valmy Formation is unconformable with overlying rocks. Silurian and Devonian rocks are not present either due to non-deposition or erosion. Unconformably overlying the Valmy Formation is the Pennsylvanian-Permian Antler overlap sequence.

- Antler Sequence: The Antler overlap sequence is composed of Pennsylvanian to Permian-aged rocks assigned to three formations: the basal Battle Formation; the Antler Peak Limestone; and the Edna Mountain Formation. These formations represent a transgressive sequence of shallow marine rocks that include conglomerate, sandstone, limestone and siltstone. There is evidence the Antler sequence was locally deposited into sub-basins developed by normal offset on growth faults of likely early Permian age. Antler sequence rocks are relatively undeformed, except for offset and rotation along Basin and Range normal faults. The Antler sequence is in thrust contact with the overlying and partially contemporaneous Havallah sequence.

- Havallah Sequence: The uppermost package of Paleozoic rocks exposed at Marigold is the Mississippian-Permian Havallah sequence. The Havallah sequence is an assemblage dominated by siltstone, metabasalt, chert, sandstone, conglomerate and carbonate rocks. These deeper water marine sediments were deposited in a fault-bounded deep-water trough and subsequently obducted over the Antler sequence along the Golconda thrust.

A series of late Cretaceous porphyritic quartz monzonite dikes crosscut the Paleozoic rock package at Marigold. The intrusions are typically several meters wide, and several can be traced along strike for tens to hundreds of meters. The dikes strike west-northwest to north and are typically steeply dipping.

There are no Mesozoic sedimentary rocks in the Marigold area; however, approximately two-thirds of Marigold is covered by Tertiary to Quaternary intercalated gravel and volcanic material.

The gold deposits at Marigold cumulatively define a north-trending alignment of gold mineralized rock more than 8 kilometers long. Gold mineralizing fluids were primarily controlled by fault structure and lithology, with tertiary influence by fold geometry. The deposition of gold was restricted to fault zones and quartzitechert dominant horizons within the Valmy Formation and high permeability units within the Antler sequence. Gold mineralization was also influenced by fold geometry in the Valmy Formation.

In oxidized rocks, gold occurs natively in fractures associated with iron oxide. Rocks within the Marigold area are oxidized to a maximum depth of approximately 450 meters. The redox boundary is not consistent throughout Marigold and is substantially influenced by lithology. Shale, argillite, and siltstone units are frequently unoxidized adjacent to pervasively oxidized quartzite horizons.

Marigold uses standard open pit mining methods. The mine conducts conventional drilling and blasting activities with a free face trim row blast to ensure stable wall rock conditions. Electronic detonators are used to control the timing of the blasthole detonation.

Mining occurs on 50 foot benches. Loading operations are performed using three primary loading shovels. Waste and ore haulage are performed with a fleet of 25 units (300 tonne) primary haulers.

With the low grade nature of the Mineral Reserves and Mineral Resources at Marigold, such large, efficient and cost effective machinery must be utilized for mining. Waste is hauled to storage locations near the mining pits to minimize haulage costs.

The Marigold processing plant and facilities incorporate standard industry ROM heap leaching, carbon adsorption, carbon desorption and electro-winning circuits to produce a final precious metal (doré) product. All processing of ore, which is oxide in nature, is completed via ROM heap leach pad, and is a cost-effective method to recover the gold produced. ROM ore is delivered to the leach pad by haulage truck and stacked in 20 foot to 40 foot lifts. At any given time, approximately 0.5 million square meters of pad area is being leached.

Barren leach solution (cyanide bearing solution, very low in gold grade) is applied selectively to different areas of the pad. The leach solution is pumped to the leach pad and the pregnant solution (gold bearing) from the leach pad is then collected in a pregnant solution pond before it is pumped to carbon column trains where gold is adsorbed from solution onto activated carbon. Carbon loaded with gold is taken from the carbon columns and t ........