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February 2008: Apex Silver commences drilling on the Viky Project. The program will consist of a minimum of 2,000 meters designed to target IP chargeability and resistivity responses at depth and significant silver, lead and zinc values in rock chip and soil samples taken at surface. [read more +]
During a 2005 regional exploration program in Central Mexico, Almaden identified an area of limestone-hosted alteration and mineralization in western Coahuila State, now known as the Viky Project. The 100% Almaden-owned 11,000 hectare claim covers an area of geology and alteration which has the potential for silver, lead, and zinc mineral deposits.
The Viky Project is one of several prospective Carbonate Replacement Deposits (CDRs) identified by Almaden during regional helicopter-borne prospecting programs in 2003, 2004 and 2005. These regions and properties, which include the Santa Isabela, San Carlos & Viky, are located within a major geological belt hosting silver, lead, zinc, copper and gold skarn as well as CRD deposits extending from Arizona in the north to central Mexico in the south. Several world class silver-zinc-lead deposits are located within the belt, including the giant San Martin deposit in Zacatecas which is currently producing ores grading approximately 120 g/t Ag, 1% Cu, 4% Zn and 0.5% Pb.
Carbonate Replacement Deposits
First recognized in Mexico and Peru in the 18th centuryand in the United States in the 19th century, carbonate replacement lead-silver-zinc deposits (CRD) are high-grade sulphide ore deposits that form in carbonate sedimentary rocks, particularly limestones. CRDs usually form vertically elongated or pod-like ore bodies that are referred to as mantos or chimneys. The large size of these deposits (averaging 10-13 million tonnes to over 50 million tonnes) and the high grades (ranging from 2-12% lead, 2-18% zinc, 60-600 g/t silver, up to 2% copper and up to 6g/t gold) make them extremely desirable targets to discover.
CRDs often form in connection with skarn deposits. Although skarns are usually associated with large areas of altered rock, CRDs are characterized by little or no alteration, often resulting in razor sharp edges between unaltered limestone and high-grade sulphide lead-zinc-silver ore. In arid environments such as Mexico, the rich silver-lead-zinc ores have oxidized, leaving high-grade silver with silver-lead-zinc oxides remaining at depths below the weathered surface. This is the environment that Almaden's management believes the Viky project represents.
The Viky prospect covers an area of replacement silicification which has developed in folded and deformed thinly bedded limestone. Eight samples taken by Almaden of altered limestone returned silver values as high as 247 g/t and averaging 102 g/t, lead values as high as 12.9% and averaging 4.3%, zinc values as high as 0.16% and averaging 0.04% and significant copper and other indicator metals typical of a silver-rich carbonate replacement style geologic environment.
2006 Soil & Rock Samples with IP planview |
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2006 Soil Samples and IP Lines |
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Summer 2007: During 2007 Apex Silver took 363 samples, mostly of rock from outcrop and float, and alluvium. Of these 71 were rock channel samples taken over an average width of 2.21 meters (ranging from 0.4 to 7 meters), the analyses of which returned an average of 9.4 g/t silver (ranging from <0.2 to 153 g/t silver), 0.42% lead (ranging from <0.0002 to 11.4 % lead) and 0.38% zinc (ranging from <0.0002 to 5.79 % zinc).
In addition 195 rock-chip samples were taken over an average width of 2.90 meters (ranging from 0.4 to 11.6 meters), the analyses of which returned an average of 16.5 g/t silver (ranging from <0.2 to 776 g/t silver), 1.22% lead (ranging from <0.0002 to 30.00% lead) and 0.53% zinc (ranging from <0.0002 to 14.35% zinc). These significant results are interpreted by Almaden to be indicative of a high potential mineralized environment. A drill program is currently being planned.
