Ron and others:
The following is hopefully of some help to you. I hope that the picture that I have drawn will help in your understanding of the situation we are dealing with.
I have to assume that you have a little understanding of geology and earth sciences.
Let us start with the sequence of events that we are most likely dealing with. From the lower portion of the picture you can see sediments have been laid down horizontally. These sediments have the characteristics of having both permeability and porosity. For those that do not have an understanding of these characteristics let me describe them and give some examples of them. Firstly, porosity is the pore space that is found between grains of sediment. Porosity is generally expressed as a % of the total volume. A demonstration of porosity might be if one took a cup of sand ( dry) and added a half cup of water. If there was no porosity you would have a cup and a half of materials, but you all know that you really have a cup of wet sand. The water has filled in the pore space. The other characteristic is permeability. This characteristic is a measurement of how well the pore spaces are connected. For example take a sponge and a block of Swiss cheese. The sponge will hold a lot more water then the Swiss cheese because the pores are interconnected in the sponge. The greater the connectivity the greater the permeability. In the context of what we are talking about in the AAG?VSY properties, the sediments have permeability and porosity and the pores are filled with water.
For some reason, (I feel that it would be to complex an issue to deal with at this level) the very hot rocks of the mantle made its way through the sediments. This is called an intrusion. Since it deals with very hot rocks originating from the mantle this would be classified as an Igneous intrusion. The intrusion will melt and assimilate the materials that are in its path. The intrusion will continue to move until it reaches criteria for it to stop. In the case of volcanoes that criteria generally is that it has reached the surface. In the case of intrusions the most likely reason for the cessation of movement would be that the temperature of the body has cooled.
As the intrusive moves up and cools it is heating up the sediments (known as country rock) that it is penetrating. The heating of the country rocks will cause percolation of the water that is in the pores. As most of you know hot water will dissolve certain things much better then when they water is cold. You may want to think of sugar dissolved into a nice cup of coffee. That water will naturally move to colder regimes, that would be away from the intrusive. As the water moves into cooler areas it cools and the goodies that it has dissolved, well they usually precipitate out. This precipitation can plug the pores and reduce both permeability and porosity. Various minerals will precipitate out at different temperatures.
Know if you consider our case, the precipitation of like minerals should be found in a circle. This may not be the case at all though, because I have described to you a case where everything is homogeneous. That is not the real world as nothing is homogeneous, The porosity, permeability, the type of sediments, the type of water, the cooling rates, the heat that was in the intrusion will all vary.
The last term that has been mentioned is a pluton. Basically a pluton is a body of solidified intrusive rocks.
Given the situation that understand we have on the property, it tough to evaluate the worth of this pluton and the halo. I would like to think that if they have found anomalous gold in the halo, that they would likely find that it has been concentrated in to a part of the halo and that it will be easily mined.
Well that is the end of lesson #1. Should you have questions, please feel free to ask. No question is a dumb one.
Good fortunes
Matt
PS Can see that my clipart picture didn't make it into the message. If you would like to have a copy of the picture let me know, I can e-mail it to you. |
