Canadian International Minerals Inc. announced it has entered into an agreement to acquire 100% of the past-producing Tisova copper deposit, located in the prolific Erzgebirge mining district in northwestern Czech Republic.
The deposit is encompassed by an Exploration Lands mineral concession, which is held by Golden Pet s.r.o., a private Czech company. The concession was granted to Golden Pet by the Czech Ministry of Environment in 2015, and carries a five year term.
The Tisova concession incorporates a former copper producer with historical production dating from the 12th century and last producing from 1959 to 1973. Most recently, the mine operated from 1959 to 1973, producing 561,000 tonnes at an average grade of 0.61% copper.
While historically the deposit was mined primarily for copper, significant concentrations of other base and precious metals have also been identified, though there appears to be no mention of their recovery in any historical documents.
Cobalt was noted in testing as early as 1901, with grades between 0.4% and 0.7%. Between 1952 and 1956, various mineral research agencies reported concentrations of up to 0.11% Co, 4.32 g/t Au, and 20 g/t Ag.
Tisova is classified as a Besshi-type Volcanogenic Massive Sulphide deposit. Such deposits are often large and, along with copper and cobalt, normally include other recoverable base and precious metals. One of the world’s largest Besshi-type deposits is the Windy Craggy deposit located in British Columbia, which has a measured geological reserve of 297,439,000 tonnes of 1.38% copper, and 0.069 % cobalt, with substantial gold and silver credits.
Two stages of drilling exploration took place at Tisova in the 1950’s and 1960’s, with more than 100 drill holes having been completed by Czechoslovak state mining companies. Drill logs exist, but under the then current economic system all core was consumed in assaying. The majority of core was only assayed for copper. Postwar exploration and development at Tisova prior to the Velvet Revolution was typically dictated by strategic, political, and military considerations rather than the strictly economic constraints that provide parameters for western style of exploration and development. The geological model was not fully understood and different criteria guided the application of funds. An exploration program in the central and southern zone of the deposit was executed during the 1971-1989, verifying mineralization down to the level of 400 m below surface. Mining was not resumed and the mine was left to flood.
The mineralized bodies at Tisova were concentrated in the three horizons: lower, central and upper. The lower was the most continuous and the central was economically most important. The known length of the lower horizon reaches 1000 m, of which 450 m has been opened by Helena mine. The mineralized zones are present in forms of irregular layers and lenses of variable size, with typical grades of 0.8 % Cu. The average thickness of lenses at the central horizon reached 2-6 m, occasionally 10 m, and exceptionally up to 30 m, with the length of 100-150 m and down dip extent of several hundred meters.
An extensive GIS database compilation is currently underway. The Company will provide a further project update upon completion of the data compilation.