Sampling Ditches

If the ditch cuts mineralized rocks or indicators of minerals (layers of iron, hydrothermal alterations, disseminated sulphurs, etc.) the samples will be taken by an incision of a stria with a hammer or chisel: vertical stria if the mineralization is attached to a stratigraphic horizon or a horizontal vein stratus; horizontal stria in the bottom part of the ditch, if the mineralization is stratiform, in a creased context or united by a vertical vein or in a disseminated form. Each sample of a quantitative determination should be carried out with a great amount of care.

Case of a sub vertical vein (potency of >0.40 cm)
The seam will be freed at a height of around fifty cm and the top part that is altered and fractured will be eliminated. Once this has been carried out the sampling operations will need to begin. The surface that is going to be sampled will be sampled if possible where it is flat and perpendicular to the vein walls and will need to carefully be washed with water and a brush. Then two parallel lines will be drawn at a distance of 15 cm from each other and normal to the walls of the seam with chalk or paint. Inside of the lines a deep hole of 5 cm will need to be dug. It is important to place attention or to not dig too deep in the soft parts or places that are not as hard; given that often times these differences in hardness correspond to differences in mineralization. The irregularities can give a false strain idea. the parts of the seam that fall will need to be carefully picked up and placed over a sheet or strip placed on the ground, that will then need to be cleaned and all the material will be placed in a recipient. The second time there will be fewer amounts in volume according to the demand of the job. The distance between a hole and another one can vary from case to case from 1 meter to 5 meters.

Case of a semi flat outcrop
The sampling technique does not differ from that one used for veins: the holes will need to be excavated perpendicularly down the mineralization length and each sample will represent the length of a variable hole from 1 meter to 5 meters.