Come By Chance – Gold-Copper
Large Copper/Gold Porphyry Deposit Target
Belmont is performing a systematic approach for proving up a large copper-gold porphyry model on the Come By Chance property.
The CBC Property located three kilometres to the southeast of the Phoenix deposits (580 Mlbs. of copper and 1.4 Moz. of gold produced) on a comparative geological trend.
Hosts skarn, epithermal, and massive sulphide mineralization; typical mineralization associated with copper/gold porphyry deposits.
Skarn mineralization with elevated copper values occurs in many locations, with epithermal zones of alteration and quartz veining
A small circular lake with a highly anomalous arsenic content centered between two major faults, appears as a hydrothermal or a collapsed breccia developed from an underlying intrusive in a volcanic environment.
LIDAR Survey Supports Copper-Gold Porphyry Model
- Lidar survey delineated the major Eagle Mountain and Lind Creek Faults which appear to enclose the porphyry breccia target and lineaments
- Crook Lake,appears as a hydrothermal or a collapsed breccia (Caldera) developed from an underlying intrusive.
- Crook Lake appears centralized to a possible large breccia pipe between the major Eagle Creek and the Lind Creek faults.
- The highly anomalous arsenic content of Crook Lake may indicate the accumulation of arsenic from an alteration zone peripheral to an intrusive.
High Resolution Magnetic Survey Further Supports
Copper-Gold Porphyry Model
- The detailed, low-level magnetic survey of the CBC property has provided a greater indication of the volcanic caldera that was initially indicated by the Lidar survey.
- The caldera is supported by a one kilometre diameter magnetic low.
- The magnetic survey also revealed the Crook Lake cross-structural zone indicated by the Lidar survey in addition to a second indicated cross-structural zone in the southern rim of the caldera.
- The significance of the cross-structures is primarily that these locations would be prime locations for hydrothermal breccia zones where mineralization has been transported from the deep-seated porphyritic intrusive responsible for the skarns.
Proposed Titan Deep Earth Imaging Survey
confirming surface exploration
- Belmont is planning to run “Quantec’s Titan DCIP & MT survey to provide high resolution resistivity and chargeability imaging at various depths.
- The MT survey will provide a depth of investigation >2000m and provide valuable information as to the overall ”plumbing system” of the potential porphyry system and fluid channels used to deliver mineralization to surface.
- The DCIP survey will provide high resolution imagery down to ~500m and potentially provide drill targets.
The Importance of Hydrothermal Brecciation
Hydrothermal breccias usually form at shallow crustal levels (<1 km) between 150 and 350 °C, when seismic or volcanic activity causes a void to open along a fault deep underground. The void draws in hot water, and as pressure in the cavity drops, the water violently boils. In addition, the sudden opening of a cavity causes rock at the sides of the fault to destabilise and implode inwards, and the broken rock gets caught up in a churning mixture of rock, steam and boiling water. Rock fragments collide with each other and the sides of the void, and the angular fragments become more rounded. Volatile gases are lost to the steam phase as boiling continues, in particular carbon dioxide. As a result, the chemistry of the fluids changes and ore minerals rapidly precipitate. Breccia-hosted ore deposits are quite common.
The morphology of breccias associated with ore deposits varies from tabular sheeted veins and clastic dikes associated with overpressured sedimentary strata, to large-scale intrusive diatreme breccias (breccia pipes), or even some synsedimentary diatremes formed solely by the overpressure of pore fluid within sedimentary basins. Hydrothermal breccias are usually formed by hydrofracturing of rocks by highly pressured hydrothermal fluids. They are typical of the epithermal ore environment and are intimately associated with intrusive-related ore deposits such as skarns, greisens and porphyry-related mineralisation. Epithermal deposits are mined for copper, silver and gold.
Greenwood-Republic Mining Camp
Lidar Survey & Mineralized Showings
Magnetic Survey & Mineralized Showings
Conceptual Model for Styles of Epithermal Gold-Silver, Breccia and Porphyry Copper Mineralization
Come By Chance Brecciation
Explosive hydrothermal brecciation. The interesting feature is the light grey fragments which appear the color of arsenopyrite (FeAsS), a mineral that can also can be associated with significant amounts of gold
The brecciated quartz veins indicate the iron content was derived from metamorphism caused by the quartz intrusion; although the iron may have been emplaced at various stages.