PROJECTS - Don Sixto (La Cabeza)
Channel Sampling Discussion
Channel rock sampling is being undertaken at all outcropping vein systems to provide an accurate and representative grade assessment over zones to be included in the Don Sixto resource calculation. The results confirm that areas of high grade mineralization intersected in drilling extend into outcrop.
A 60mm wide by 30mm deep channel (approximately equivalent to half HQ size core) is cut into the surface rock using a portable electric handsaw with a diamond-tipped blade. The sample is then collected in two metre intervals using an electric hammer drill to break the sawn rock within the channel. The geology of the channels is logged by an experienced geologist. Where there is good outcrop, channels are cut directly into the outcropping rock. In places where there is shallow soil or scree cover, the areas to be channel-sampled have been cleaned by hand and/or bulldozer to expose bedrock prior to the cutting of the channels. In some cases, the cleared areas were washed down to better expose the bedrock. Zones where definite bedrock could not be exposed (i.e.: zones of caliche) were not sampled.
In general, channel samples have been cut over the surface trace of existing drill sections to provide direct surface assay correlations with drilling assay data. In many cases, channels have been cut between drill sections to provide additional surface geological and geochemical data.
The location of the start and finish point of each sample has been surveyed by a professional surveying contractor to provide an accurate location and level of each sample that can then be correlated directly with drill assay and geology data.
As the channel samples are collected over an irregular surface, the true width of mineralisation from each sample is variable dependant on the surface slope and the orientation (dip) of the mineralisation at surface. Hence the results are best used as a guide to confidently project mineralisation to surface from subsurface drill hole data. Estimates of true widths of surface mineralisation can be made once data is plotted on geological cross sections incorporating topographic, geology and assay data. The results obtained from the channel sampling provide confidence in projecting mineralisation intersected in drill holes to surface.
AMEX : XRA TSX Venture : XRC FRANKFURT : EXB