First Glimpse of Represa Geology!
posted on
May 08, 2008 09:20PM
Camino Rojo Mexico : In-situ - 4.0 million ounces gold; 68.32 million ounces of silver.
Now we're talkin'... ROCK DATA. The company posted a new x-section on the website. I have posted it in the PHOTO section of the board.
What does it mean? Certainly it is too early to draw many intelligent conclusions and the following is only a quick review of the x-section. I do wish GeoInvestor was about to add his impressions. My observations are not etched in “stone” and I’m anxious to hear what others see! As is always the case, limited data only begins to reveal the geological story of any deposit and interpretations will be refined as more core data is added. IMO this section is an excellent first view of the deposit's stratigraphy.
First, the sequence of rocks does follow the regional pattern, siltstone and sandstone underlain by limestone and marble. Second, the intrusive rock is granodiorite and it seems to be mineralized. Third, CRD-4 crossed the "fault" around the 75900N line and the section does not show it. One sandstone bed near the surface in CRD-1 does not extend south, across the "fault" into CRD-4 and the deeper sandstone beds do appear in both core holes.
It is too early to draw any conclusions about the existence or offset of the "fault". The shallow sandstone bed may just pinch out to the south, a deeper siltstone bed shows up in CRD-1 and is mapped as pinching out to the south since it was not picked up in CRD-4. This is not unusual, sedimentary beds do pinch out laterally as the original depositional environment changes, a "facies" change. The good news here IMO is that it does seem less likely that the "fault" is a game breaker to the west! This is strongly indicated by results from CR-32 and CRD-9.
What is interesting is that the granodiorite dike that is shown as being penetrated by CRD-3 seems to truncate a thick sequence of limestone to the north. CRD-4 passes through the limestone and then back into siltstone immediately south of the intrusive dike. The sequence in CRD-1, CRD-3 and then CRD-4 is difficult to resolve, it may be that the intrusive that is shown in the CRD-3 core may occupy a fault, notice that all 3 holes converge around the 1350m elevation.
CRD-1 penetrated the marble and shows that in this locality, the marble is not mineralized. That does not mean that this is the case everywhere and the confirmation of marble at depth does IMO increases the likelihood of high-grade skarn mineralization is a real possibility elsewhere in the deposit as predicted in the Canplats "Conceptual Model".
One thing that is not included in this lithological section is a call on the nature or extent of the breccias in the core. However, at this point one can assume that where there is mineralization, the rock is brecciated. I hope that they have core in Vegas that I can look at!
These are just my first glance observations and are open to revised interpretation and I expect others will add their observations and even disagree with my initial guesses. I am fine with that, after all we are all here to learn from each other and to have a civil exchange of ideas. With a little data one can ask more informed questions and finally I feel that I am not just taking " a shot in the dark" anymore.
Not investment advice, look at the data and post your own impressions.