Rock outcrop

What can happen is that the prospector mist verify the characteristics of the trace matter found by surface work, specially if it’s isolated evidence found in a hard access region. These Mining Jobs consists of:

• Make a ditch (or trench) over the evidence, with the objective of determining the geometrical characteristics of the outcrop: dimensions, consistency, if it’s veilets include direction & pitch.
• Another two ditches will be made ten meters away on each side, on the supposed prolonged and perpendicular direction. If possible they must reach the rocky substratum.

The function of these tasks is to show that the found deposit continues longitude ways and to check that the evidence found, commonly poor in matter because it is lixiviated on the surface, is richer in the covered deeper part. They are light work essentially done to provide data to fill out the evidence file. The systematic prospecting using trenching is dealt more thoroughly further on. This work shouldn’t last more than a week, even if in this time no interesting data has come up. The results obtained, even if negative, should be reported in the aforementioned evidence file.

B) Sampling

In this first phase of mine searching, sampling must be done with a more quality than quantity objective.

Difference scenarios may come up:

If the mineral deposit outcrops, take more samples for polished studying similar to petrographic samples and also several hundred grams to a kilo of samples for analysis. The more heterogeneous the mineral is, the more samples are needed. In any case they must be the most possible joint representatives of mineralization.

In the case of an iron peak, take 10-15 samples of the body of the peak & the most different possible aspects; as for a multi-element analysis because trace elements often allow you to establish if an Fe peak is derived or not from useful sulfurs. In the case of a pyrite rock or disseminated sulfurs, a rock that has suffered hydrothermal alterations & a rock that contains disseminated oxidation products, it is recommended to sample rock notches, by hammer, avoiding visible mineralized points. It’s clear that the objective of the search is quality and the results that are proportioned from the analysis should be taken to the letter. Needing one or more samples of 2-3 kg made up of various notches, specially of the mineralized outcrop. The samples can be placed in plastic or cloth bags, with the number written on the outside and with the same number written on a card placed in the inside.  Samples can be then sent directly to the laboratory or they can be prepared on the field by mortar grinding, cracking, sieving, depending on what was agreed upon by the person responsible of analysis & the type of analysis needed.

Tray loaming & quartz washing (dolliyng)

When sampling auriferous quartz veinlets (often with invisible gold), a quartz mineralization exam will be needed. If its compact without sulfur traces or of its oxidized products or cavities covered by a ferruginous layer, time shouldn’t be wasted on these samples. If on the contrary the quartz exam has shown the presence of sulfur and waste, proceed in the following way.