Searching the Roots of Abnormalities

After the top of the abnormality has been well defined, the surface will be searched for, by samples in depth, if this superficial image corresponds to an image at the level of the bed rock in the in situ rock. In order to do this it will be necessary to cut the abnormality with one or more profiles by means of samples with drills that can be manual or the motor ones. In the case of the presence of rock, by the study of the primary aureole the sampling will be done over the witnesses of the drills or the cuttings in case of a destructive drill. 

Samples
Once the type of sampling has been fixed and the localization point in the map, the practical problem of knowing where to sample and how to take the sample from the terrain is the practical problem that is created for the prospector. Each found situation will be different but there are some cases that can be schematized.

Stream sediment samples in the hydrographic net

• Fine stream sediments sampling done on the active bed in the water but not far from the current so as to avoid sampling material that has been washed out too much. This type of sampling is the one that best corresponds to the term stream sediment.
• Ground sampling of alluviums and colluviums in cases where the alluviums in the active bed is big or in cases where there is not any at all. This sampling is done on the clay parts of the banks that are in contact with the water. 
• Ground sampling on the bottom of the valleys, in case of the absence of alluviums.

The objective of these samples is that of being representative of a certain hydrographic basin; therefore avoid sampling the main collectors where possible mineral contribution can be diluted by the other contribution of other courses of sterile waters. Make sure to not sample too close to the confluences but rather a little further upstream in the secondary collector. A sampling of white sand is not considered a good thing because it does not have a fraction of fine clay, in the same way it is important to not pick up a sample that is too rich in organic material (samples that are black for example). In tropical countries, a good sample normally has a grey or dark brown color to it. Note: it is suggested whenever possible to pick up the feces of the worms that can be found in the river banks as closely as possible to the water stream. This is an optimal particle size material that is completely cleaned by the animal of all the organic material.