The Back 40 Joint Venture in

by Tom Quigley: President of Minerals Processing Corporation

As a follow up to the identification of potential minerals in the subsurface, we started drilling last fall to extract continuous cores of the bedrock below us for further analysis and evaluation.  The diamond studded drill bits cut through solid rock to provide us with a continuous sample of what is really down there. We carefully laid these out, marked, and logged them as to rock type, mineral composition, and other geologic features. 

Back at the field office under the bright halogen lights we visually inspect and select portions of the core for chemical analysis.  These portions are then sawed longitudinally in half with our 20 inch diamond saws to produce two equal halves.  One half is broken up with a hammer and placed in a cloth bag, logged, and shipped FedEx to the Chemex preparation laboratory in Elko, Nevada for processing.  The other half is retained here as a reference sample.  At the lab, the core sample is crushed and blended. A small portion of this sample is then pulverized into a very fine powder and sent to Chemex Labs in Vancouver BC for chemical analyses.

This pulverized portion, or pulp, is then analyzed for a variety of elements, depending on what minerals we suspected to be present.  Labs offer different analytical packages for a wide variety of elements.  We normally request a multi-element package that includes 27 elements, including elements of value such as copper, zinc, gold and silver, as well as uncommon elements such as zirconium and barium, that help characterize or “fingerprint” the rock.

These elements are usually only present in trace amounts (trace elements), and
are reported in parts per million (PPM). In cases where larger amounts are present, 
results are reported in percent.  10,000 PPM equals 1%.  In general, for elements of
economic interest, the abundance of the element is proportional to its value.  For
example, gold, which currently sells for about $375 per troy oz (a troy oz is slightly
larger than a normal oz), rarely occurs in concentrations greater than 1ppm, and a gold deposit often only averages 5 to 10 PPM.

Zinc on the other hand sells for 40 cents a lb., and has background levels in most rocks of 20 to 200 PPM, and can average 5% to 15% zinc (50,000 to 150,000 PPM) in a zinc deposit.

As an example, a mineralized and un-mineralized interval of core from our drill hole #31 contained the following assays: in (PPM) 

#605 at 340 ft. down 
#614 at 275 ft. down 

#	Zinc	Gold	Silver	Copper
605	137,000	4.3	35.3	7,902
614	3,160	.04	2.0	140

Cold temperatures and biting winds have not prevented Minerals Processing Corporation (MPC) from working on their Back 40 mineral exploration project west of Stephenson.  According to MPC, the Back 40 project is in a data collection and compilation phase. Currently, a team of MPC field technicians is in the process of gathering information on land they either own or have permission to access. The intent is to expand the exploration database that the company uses to locate potential areas of mineralization in the rocks below.

“Most of the work right now involves surveying lines through the woods and measuring out evenly spaced points, or stations, along those lines.  Geophysical readings are then taken at each station,” explains Bob Mahin, Senior Geologist for MPC.

The geophysical readings involve the use of sophisticated equipment that measures the gravitational field at each station.  According to Mahin, “Different kinds of bedrock can subtly affect the gravity readings. After we collect and compile the data, we try to deduce what the subsurface geology is like based on the changes in the geophysical readings.” 

Since there is virtually no outcropping bedrock in the area that MPC is exploring, they have to resort to indirect methods such as this to try and determine what kind of rocks are hidden below.  In addition to measuring the gravity, the field crew may use different equipment to measure the magnetism or the conductivity of the bedrock--all of which the geologists are hoping will provide clues to the location of buried mineralization.

For example, a pod of mineralization that is much denser than the surrounding bedrock can result in a measurable increase in the gravitational field directly over it.  Other geophysical data might indicate the presence of a concentration of conductive or magnetic mineralization that could be an ore body.  “Think of it as high tech water witching,” comments Mahin.

“The only way to know what’s down there for sure is to drill a test hole, but drilling is very expensive,” adds Mahin.  “The geophysical data helps us narrow down our drill targets.”

Minerals Processing Corporation intends to continue to a next phase of exploratory drilling after they have completed the geophysical surveys.