SEMAFO's Yaho Zone more than doubles strike length - consistent wide gold mineralizations
Montreal, Quebec, Wednesday , 29 Jun 2011
SEMAFO (TSX: SMF) announced today that follow-up drilling has more than doubled the strike length of the gold mineralization to more than 1.5 kilometers on its recently discovered Yaho Zone. Initial drilling (reference SEMAFO's press release dated March 3, 2011) identified a continuous strike length over 600 meters. Follow-up drilling has extended the gold zone to the south and to the north with a total current strike length of more than 1.5 kilometers. The Yaho Zone remains open on strike and at depth.
In addition, three core drill holes have been completed in order to characterize the geological environment of the mineralization and understand the structural controls. Assay results from the core holes remain pending.
For drill results tabulation click [here: LINK]
The second phase of RC and core drilling provides a better understanding of the area's host rock. The Yaho Zone is hosted by a clastic sedimentary unit which varies from a conglomerate to a quartz-rich sandstone (Figure 1). The conglomerate beds observed are polymictic with abundant quartz-rich clasts and occasional rounded clasts of volcanic origin. The clastic unit is bounded by basaltic flows to the west and a sequence of fine graphitic sediments and volcanoclastics to the east. Alteration is constrained to the clastic unit and consists of strong pervasive sericitization and silicification. Some quartz veining is also present, although not pervasive. Mineralization occurs as a series of stacked zones varying in widths of up to 19 meters on the three newly drilled sections. Mineralization includes disseminated pyrite and arsenopyrite in varying amounts, ranging up to 5 to 10 percent locally. As shown in Figure 2, anomalous gold grades are very common in the clastic unit with many higher-grade sections, which appear to continue at depth from hole to hole over wide intervals. Gold grades obtained across the mineralized zone show excellent consistency, which also suggests that a similar regular grade distribution probably occurs along strike.
Section 1,310,200N is virtually perpendicular to the zone and shows a moderate dip of both the host unit and the gold-bearing zones. The host unit trends generally north-south but is also folded along an east-west fold axis, representing a second phase of folding commonly seen across the entire property. The core of the zone seems to be located at the hinge of the latter folding, although the details of the geometry remain to be clearly established.
"The Yaho Zone represents a new style of mineralization, considerably different from Wona and Nyafé," states Michel Crevier, SEMAFO's Vice-President, Exploration and Mine Geology. "Recent work provides a much better understanding of the Yaho Zone, which will assist us in determining future work to ultimately increase resources. It also further accentuates Mana's exceptional potential as host to various styles of mineralization."
Additional drilling at Yaho will include delineation of the currently known 1.5- to 2-kilometer strike length, as well as further exploration of sections to the north and south to extend the strike potential.
We are experiencing significant delays in obtaining drill results due to substantial backlog at the independent assays laboratories in Ouagadougou. We therefore anticipate receipt of preliminary drilling results for the Massala and Saoura areas in July. Consequently, SEMAFO has decided to build an exploration laboratory to be located on the Mana property. This facility will significantly reduce the turnaround time for drilling assay results and accelerate the reporting process.
The exploration programs were designed and managed locally by Dofinta Bondé and David Legault, Mana Mineral's Exploration Chief Geologists, David Lalonde, Deputy Exploration Manager, and Richard Roy, P. Geo, Exploration Manager, and guided and supervised under the direction of Michel Crevier, P.Geo MScA, Vice-President, Exploration and Mine Geology and SEMAFO's Qualified Person who has reviewed this press release for accuracy and compliance with National Instrument 43-101.
For RC drilling, all individual samples represent approximately one-meter in length of rock chips homogenized and riffle-split to an approximately 2 kilogram subsample, which is sent for preparation and gold assaying at the ALS Chemex laboratories in Ouagadougou, Burkina Faso. Each sample is fire-assayed for gold content on a 50-gram sub-sample at the same ALS Chemex laboratories. In addition to ALS Chemex's own quality assurance/quality control ("QA/QC") program, an internal QA/QC program is in place throughout the sampling program, using blind duplicates, blanks and recognized industry standards.
======================================
