Berta corresponds to a porphyry copper system. In detail, Berta Sur exhibits evidence of alteration and mineralization which is comparable with that observed in the deepest parts of such systems. In particular the textural variations from TON to a crystal rich PTC, the background potassic alteration, the development of muscovite and greisen", and the Ca-Na alteration, are typical characteristics of the roots of porphyry systems (Dilles, et. al., 2000; Seedorf et. al., 2008). These characteristics also explain the lack of development of significant mineralization at depth. Rather the mineralization decreases in grade with depth or has a root-like shape becoming narrower in depth.

The interpretation at a local level shows variations from north to south, with the development of propyllitic alteration and NW oriented D type vein system with sericitic halo in the north passing to zones of breccia and the development of porphyry with potassic alteration in the south. This suggests a relatively deeper level of erosion toward the south and east, produced by NW oriented block faulting, which have segmented the porphyry system.

The copper oxide mineralization at Berta extends to depths of 30 to 100 m with mineralization outcropping at surface and with effectively no overburden. It has a simple mineral material and gangue mineralogy, excellent response to leaching and fairly continuous Cu grades and sharp contacts with low-grade margin mineralization. These favor ........

Mining at Berta would be carried out by open pit methods.

The drilling and blasting should be evaluated together, as drill hole diameter and explosive charge factors that ensure correct fragmentation, must be reconciled. Geotechnical and rock mechanics data is used to make a correct estimation of equipment and cost.

According the geotechnical information of the deposit, two material types, mineral material and waste have been defined.

Two drilling diameters, 51/2" and 6 1/2", based on bench height and the geotechnical characteristics of similar deposits were assumed.

It has been assumed that the base load will be HEAVY ANFO (HANFO), and for loading a column, ANFO NORMAL. Any holes making water will be loaded with an emulsion of 60% HEAVY ANFO.

The loading and hauling should be analysed together to determine the compatibility of the units. The aspects to evaluate are:
- Physical Match: the dimension of the equipment must be compatible. The height of the dump trucks must be such that the loading equipment is capable of that height to load them.
- Productivity Match: the number of passes required to load a truck must be taken in account. High productivity is considered a match of 3 to 4 passes. It is planned to use 25ton dump trucks and 3.7yd3 loaders which results in medium productivity, as they require 5 passes to load a truck.

As for drilling and blasting, the GRAVEL type material has an important eff ........

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