Starting A New Mine After Magnetic, Resistivity And I.p Survey.

[bloodgold2]

On 05/03/2017 at 3:23 AM, Steve Herschbach said:

Ultimately geophysical prospecting just provides clues. Each clue is put together in context with all the other clues and judgement calls made. A magnetic survey for instance just reveals magnetic anomalies. This could be a clue to a valuable resource, or perhaps just a zone with more magnetite than the surrounding rock. Very many places that return what look like exciting results via geophysical surveys never prove out to be mines. And I have seen places where mines are that have been subjected to geophysical survey after the fact, with surprisingly little result.

I tend to think in terms of strong clues and weak clues. Actual physical results by way of surface sampling, digging pits, drilling, etc. are strong clues. Geophysical methods by and large in my opinion are weak clues. They have to be taken together with all the information you have to provide an overall picture, but taken alone and separately are not much to go on. I would advise caution as there are people that put far too much weight on geophysical survey results alone. They would tend to be the type who are looking for investors. Just my opinion as a layman however.

There are people here with more knowledge and experience than I and hopefully they will chime in. The reality is this sort of thing is beyond the scope of this forum and most of the people here are not involved in such things so you may find better sources of information elsewhere.

Here is an old guide (1968) that provides some easy to understand practical information:

HANDBOOK OF GEOPHYSICAL PROSPECTING METHODS FOR THE ALASKAN PROSPECTOR

I agree Steve, we have used magnetic maps as well but sometimes the shed if any can be some distance off the anomaly. Rios, if it was me I would be looking if your lease is in the main run on the magnetic maps of the others that are producing gold. Other than that all I can say is you only live once.

[rios]

2 hours ago, bloodgold2 said:

I agree Steve, we have used magnetic maps as well but sometimes the shed if any can be some distance off the anomaly. Rios, if it was me I would be looking if your lease is in the main run on the magnetic maps of the others that are producing gold. Other than that all I can say is you only live once.

I hear. My plan now is to do a mag starting from where the other guys are mining running all the way to my claim. I think the level of confidence can increase a bit after that.

 

[rios]

I  picked  rubble  from the  ground  and  took  100g  sample  for  fire  assay.  The result was 26g/ton.  That  is  quite  encouraging.  

[rios]

We have  since  done  a  trenching  job  across  the  claim  and  the results  were  as  attached.  

The  trench  was  about  1.5m  deep  and  hit  bedrock.  Our  samples  though  were  mainly  soil  samples  taken  every  meter.

The  best  result  there  was  a  big  quartz  rock  which  unfortunately  did  not seem  like it  was  part  of  a  continuous  reef.  It  was  if  someone buried  there,  how and  why i  have  no  clue. It  had  a  bit  of  visible  gold.  

I am  not  sure  the results  are  good  enough 

[klunker]

 Thanks for the update Rios. I just doesn't seem logical for the quarts boulder to have been "placed" there by a human. What is the rock type of the bed rock?

[rios]

Sample  9's  origins  are  yet  to  be  established.  I suppose  there  is  no  harm in  further  opening  up  where  the rock  was  and  checking  whats  going  on.  How  does  such  a  rock  just  appear  from  nowhere?

 

Bedrock  is  schist.  We didnt  dig  much  into it though  we  know  from  the  other  shafts  (like  the  4m  one  below) its  a  few  meters  deep  before  one  encounters  more  competent  rock  in  the form  of  bluestone  and  granite  on  the  other side

[jasong]

Interesting stuff, keep us updated.

Is it hilly? Hard to tell from the photo. The rock probably travelled downhill.

[rios]

6 minutes ago, jasong said:

Interesting stuff, keep us updated.

Is it hilly? Hard to tell from the photo. The rock probably travelled downhill.

The  area  is  really  flat. Flat  for  miles. 

[jasong]

Have a map of faults in the area? Might be worth tracking if you find more out of place rocks.

There is a large plain near where I live which is flat right now but has sequences of much older rocks in the alluvium due to a huge block that was faulted down. At one time there were mountains, but they "fell" slowly, filling in the valleys and leaving a large flat plain after erosion leveled off the parts of the peaks which didn't sink completely underground. So, there are lots of out of place rocks there, and often they can indicate what lies underneath, or where "underneath" was 100 million years ago, which is now somewhere else.