Archie-MacKenzie
The Archie-Mackenzie Project comprises Archie EPM 15073 and Mackenzie EPM 15071, covering a total area of 491km2. The Archie-Mackenzie tenements are located approximately 50km north of the Century Zinc mine.
Geological setting
The Archie-Mackenzie Project lies in the Mt Isa Block Lawn Hill Platform region covering the interpreted equivalents of Mesoproterozoic Termite Range and Lawn Hill Formations below cover of the Mesozoic Carpentarian Basin.
The interpreted oldest basement rocks are Archaean or Palaeoproterozoic rocks thought to underlie the Calvert and Isa Superbasins. Overlying the basement are several rift-sag cycles of the Calvert and Isa Superbasins ranging in age from ca 1700 Ma to 1590 Ma. This style of basin architecture is favourable for base metal deposits. The Isa Superbasin architecture and tectonic history have an important influence on the base metal mineral potential.
Outcrop in the Archie-Mackenzie Project has been mapped on Queensland government geology maps as mostly Cainozoic alluvium, ferricrete and sand. Only one small area on EPM 15071 is mapped as outcropping Proterozoic Termite Range Formation. Based on previous drilling, Mesozoic cover depth in the project area is estimated to be less than 100m in the western part of the project area, but up to 170m depth in eastern parts.
Exploration Potential
The Project has potential for the discovery of Century or Mt Isa style stratabound zinc-lead deposits formed during rift-sag events. There is potential for Mt Isa and Gunpowder style copper mineralisation to form on major faults.
The ingredients for a world class deposit are present; potential for base metal sources in the basement and basin fill, transport mechanism by brines both during the sag and inversion phases and metal traps by replacement of reducing sediments. The position of the Archie-Mackenzie EPM’s high in the Proterozoic geological sequence with major structures located on synclinal axes, are features consistent with the conceptual model of mineralisation of the Century style.
The recognition of these settings from geophysical data is in its infancy leaving open the opportunity to develop new strategies and apply new techniques to explore in this area with potential to be very productive.
There has been limited exploration in the area. Geophysical methods have been the dominant exploration tool with aeromagnetic and gravity used extensively to delineate the depth to Proterozoic basement and to define favourable structure.
Exploration Program
The tenements were granted for a period of 5 years in September 2007. Initial field exploration commenced in May 2008 with the completion of a geochemical soil survey using the Ionic Leach assay technique.
A review of geophysical data and structural modeling was completed using the services of consulting group GeoDiscovery in July 2008. A number of potential drill targets have been identified and are being assessed for near future drilling.
