In Situ Leach Mining Characterization
Site specific geologic data are critical to evaluate the applicability of ISLM to a mineral deposit. Examples of data collected are regional and local stratigraphic information, geometric configuration of the ore body, geologic structure including orientations of fractures and faults, effective porosity and permeability of bedded rock units, interconnectivity of cross-cutting fractures, and regional and local hydrologic conditions.
Manganese mineral textures include massive, fracture-hosted, disseminated, interstitial, and encapsulated. Physical relationships between ore and gangue minerals include grain boundary relationships, grain sizes, effective surface areas, and the location and abundance of ore and gangue minerals with respect to the rock matrix and microfractures.
The stratigraphic top of the iron-formation is a hematitic chert unit (average thickness 40 m, 131 ft). This unit consists of an upper subunit of thin-bedded chert (average thickness 7 m, 22 ft) and a lower subunit of massive, hematite- and goethite- spotted, oolitic chert (average thickness 33 m, 109 ft). Locally, this chert is replaced by massive hematite and minor goethite, especially towards the base of the subunit. Manganese content in this unit is less than 1%.
Virginia Formation: 51.5-97.8 m, 169-321 ft depth. This formation consists of a well-bedded,