|Location: Chihuahu, Mexico||Stage: Production|
|Size: 11,319 ha||Mill: Malpaso Mill|
|Ownership: 100.00%||Capacity: 19,500 tpm|
The Company’s Cusi Property encompasses 60 concessions covering 11,319 hectares that include 12 inactive mines, each located on a mineralized structure, and which lie within 40 kilometres of the Malpaso Mill. These former mines produced high-grade silver but became inactive when silver prices dipped several decades ago. Management believes the district is under-explored and has not been subject to modern exploration methods, and is engaged in an active exploration programme to develop the various ore bodies on the property.
During the exploration and development stage, Dia Bras has been able to utilize the Malpaso Mill to generate revenues from the sale of development mineralized rock. The Company has optimized the vat leaching circuit at the Malpaso Mill in order to achieve the combined flotation/leaching recovery above 85%.
|3 Months Ended||12 Months Ended|
|Jun 30, 2012||Sep 30, 2012||Dec 31, 2012||March 31, 2013||March 31, 2013|
|Lead (000 lb)||126||185||126||149||586|
(For a detailed summary of production please click here)
A NI 43-101 technical report for Cusi was prepared by RPA Inc and filed on SEDAR on December 20, 2006. Between the end of 2006 and the end of 2012, the Company has completed 114,881 meters of drilling on the property and anticipates releasing an updated NI 43-101 Technical Report on the Cusi property, in the second half of 2013.
Rocks in the Cusi area are mainly volcanic rocks of the Sierra Madre Occidental, predominantly volcanic rocks of Eocene-Oligocene age, continental deposits of the Upper-Middle Tertiary, and in smaller proportion, Quaternary deposits. The geologic column comprises a sequence of volcanic rocks, with a minimum thickness of 750 m in “La Bufa” mountain, but possibly thicker since its base is not exposed nor it has been reached by the deepest mining operations. Volcanic rocks in the area are of the Lower Volcanic Series, the base of which is represented by felsic lavas and tuff dated at 37 Ma. They overlie a sequence of 37 Ma old agglomerates and andesitic lavas with a smaller amount of intercalated volcano-clastic sediments and andesitic tuffs.
The Upper Volcanic Series unconformably overlies the earlier series and is represented by felsic, intermediate and mafic volcanic rocks with an age range of 36-27 Ma. The mafic rocks originated during periods of faulting and are represented by andesitic basalts dated at 28 Ma. The rhyolitic rocks, such as tuffs, breccias and ignimbrites, belong to the Sierra Madre Occidental Superior Volcanic Group.
The rocks are intruded and altered by monzonitic intrusions and cut by rhyolitic dykes associated with Ag-Pb-Zn-Cu-Au mineralization.
Epithermal (silver dominant) and base-metal veins occur as hydrothermal fissures filling faults and fractures. The veins are generally narrow, vuggy and chalcedonic and fill major structures. The faults that host veins are undulatory in both strike and dip and fracturing and brecciation increase at inflection points that often correlate with cross structures/veins. Broad zones of disseminated silver mineralization occur at some of these structural intersections, most notably at the Promontorio mine.
The length of the major structures varies between 500 to 2,000 m, with high grade zones and also barren sections. Second and third-order faults are of much shorter length, on the order of tens to a few hundred meters. Alteration is mainly silicification, oxidation and cloritization.
Currently, the Company is completing an aggressive drill programme to expand the disseminated silver type mineralization at the Promontorio Mine and test other high priority targets on the project including the El Gallo and Santa Eduwiges targets. Additionally, at the Promontorio and Santa Eduwiges mines development work to extend ramps to depth and development of stopes to access high-grade ore will be completed. An updated NI 43-101 compliant resource estimate is estimate to be completed in early 2013.