Drill Results Reported From Stevens Basin Project
VANCOUVER, BC - Columbus Gold Corporation reported Phase I drilling results by JV partner, Navaho Gold PTY Ltd at Columbus Gold's Stevens Basin project located in Nevada. Navaho Gold can earn an initial 51% interest in Stevens Basin over a 3 year period by incurring exploration expenditures of $3 million and making cash and share payments to Columbus Gold.
Assay results have been received from 2,390 meters (7,840 ft) of drilling in 14 reverse circulation drill holes completed by Navaho Gold during May and June 2011. The majority of the drilling was designed to test soil and rock chip gold geochemical anomalism and was integrated with geophysical data (ground gravity and airborne magnetic data) acquired by Navaho Gold to select drill sites. Three sites (holes SB11-09, 10 and 13) were selected in areas of no outcrop on inferred structural features alone.
Stevens Basin is an unusual gravel-filled semi-circular basin, approximately 10-13 km(2) in area. Surrounding this basin are hills of Paleozoic sedimentary rocks which, along its northern margin, consist of mainly Devonian age limestone containing areas of altered and mineralized intrusive rock and siltstone float. In the area where the drilling was conducted the target horizon is a calcareous siltstone unit inferred to dip off the outcropping limestone out under the gravel cover. Based on the conventional model for Carlin-style deposits, mineralization is expected to be best developed where the prospective host unit intersects controlling structures capable of introducing the mineralizing fluids.
Six (6) of the 14 holes drilled contain encouraging intercepts of low-grade gold mineralization which, when combined with strongly anomalous arsenic (As), antimony (Sb), barium (Ba), thallium (Tl) and zinc (Zn) also intersected in many of the holes may indicate proximity to higher grade Carlin-style mineralization. Using a cut-off grade of 0.1 g/t Au over minimum interval of 3m and no more than 1.5m internal dilution, the following encouraging intercepts were returned: SB11-003 4.6m @ 0.30 g/t Au from 64m; SB11-009 15.2m @ 0.18 g/t Au from 35m; SB11-014 4.6m @ 0.25 g/t Au from 41m.
Mineralization in these 3 holes is hosted within oxidized, sheared and variably fractured/brecciated limestone with extensive calcite veining and jasperoid development (decalcification and silicification - usually associated with a Carlin-style gold mineralized system).
All 14 holes returned intercepts containing anomalous (greater than 10ppb or 0.010g/t) values of gold. Of particular importance is the thickness of the anomalous gold interval in SB11-09 (109.7m from 1.5m depth) which indicates a significant gold-bearing hydrothermal system has been identified.
In addition to the elevated gold intercepts several holes encountered zones of anomalous arsenic (up to 0.15% As over 9.1m in SB11-05; 0.13% As over 36.6m in SB11-012), anomalous zinc (2.03% Zn over 7.6m in SB11-11), anomalous barium (0.47% Ba over 87m in SB11-11; 0.84% Ba over 6.1m in SB11-05; 0.77% Ba over 7.6m in SB11-10) and thallium (2.4ppm Tl over 12.2m in SB11-05; 1.5ppm Tl over 74.7m in SB11-09; 3ppm Tl over 7.6m in SB11-10; 1.5ppm Tl over 83.8m in SB11-13). These elements are all strong indicators of a Carlin-style system. The company's address is Suite 307 - 475 Howe Street, Vancouver, BC V6C 2B3, 604-634-0970, fax: 604-634-0971, email: [email protected].