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Message: Coach's comments on La Yesca's 43-101 Tech Report

Coach's comments on La Yesca's 43-101 Tech Report

posted on Sep 20, 2007 04:00PM

FYI - this forum is off to a great start with lots of good info and contributions. I kept this post from Coach dated August 15 2006 and thought readers doing their DD would find his comments very helpful.

 

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I am reading through the technical report filed on sedar. I will try to sum up the details as best I can just to highlight some of the more interesting info.

The property is located outside of the main center of Hostotipaquillo, which is a small town with a couple of gas stations, some liquor stores, and minor services but not much else. I stopped there to get a flat tire fixed during my visit to the Cinco Minas Project operated by Bandera Gold. Once you get off the main paved highway, you are driving for over an hour on winding, steeply terraced, dusty gravel roads. They allow for access by 4-wheel drive vehicles, but are often impassable during heavy rain in the summer months, and will have to be improved to allow for the passage of heavy equipment.

The deposit was first mined by Spanish colonists, which means it is one in which mineralization was visible from surface outcrops, since no sophisticated exploration techniques were available at that time to test for blind discoveries. It also suggests the area is intensely mineralized or the Spanish would never have bothered with it. Typically, mines that graded below 3,000 g/t silver were considered below cutoff value and ignored.

Since no large scale mining activity was conducted on the property during the last 40 years or more, it is probable that the workings only went to shallow depths and end at the water table. Sulphide ores lying below would not have been economic to process using the recovery technology of the day, and efficient pumps to keep the lower levels from flooding were not available at that time. However, most other epithermal deposits in Mexico have been demonstrated to extend to much deeper levels than the limits of past production, so there is a good exploration prospect right at the edge of the current workings.

As for the geology, again it is typical for the region. You have an older layer of volcanic rocks that are mostly barren of metals. The host rock was then intruded by a granitic batholyth and over many thousands of years the mineral bearing fluids were injected into the host rock formations under heat and presure, emplacing the ore bodies. A period of faulting and seismic activity followed during which the mountains were heaved up, exposing the vein structures to erosion and forming the outcrops from which the discovery of the deposits were made.

The nature of this kind of formation is variable. If fluids were circulating into the host rock for a longer duration, then the entire rock formation would be subjected to heating and allow for a larger zone of alteration. If the fluids were injected into wide cracks and fissures and presure and heat rapidly disappated, then you would have more localized narrow vein structures formed.

One part of the report suggests the presence of a silica cap above a fault structure. That is significant as it would trap mineralizing fluids within the fault, allowing a longer period of alteration and potentially higher grading mineral emplacement since the fluids could not rise beyond the cap.

The large number of nearby mines would suggest that the property is part of a regional system. A couple of higher magnetic anomalies on either side of the property may indicate a larger massive sulphide ore body at depth.

There is a large tonnage of tailings from past production that has demonstrated potential for economic processing by UC. There is also residual higher grade ore in the mines that can be extracted, and the potential for additional resource discovery. Part of the discovery potential comes from the possibility of a lower grade bulk tonnage target surrounding the higher grade vein system, which is a similar exploration model to what UC has underway at Copalquin.

One key point from the report is that there are no environmental issues that are a concern to process the tailings, which is very important since any legacy issues would become the responsibility of UC if they touch the tailings. The local residents welcome mining development, and again that is something that I witnessed for myself at the nearby Bandera project. The region is subject to intense poverty, and as long as mining is conducted in sustainable practice that involves locals as stakeholders and participants, then there are benefits for the entire community.

Overall, the project looks like a good opportunity. There is an obvious mineral system in the region that has yielded higher grade ore in the past. The geology is similar to other systems that have been mined for centuries and continue to yield new discoveries. There has not been a concentrated exploration effort yet to test the area using a regional model. And there is a real potential for a much larger bulk tonnage system that could amount to a large resource. And in the meantime, there is a good tonnage of tailings to process, which will have to be drilled off to prove up a reliable estimate, but will probably be suitable to generate positive cash flow while the project is subjected to further exploration.

I am not a geologist, so I have tried to make my summary as accurate as possible but if there are any unintentional errors I welcome others to correct them.

cheers!

COACH247

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