Prospecting of Littoral Formations

First phase:
This job is done at the beginning of the search, it is very quick, economical and is done by using a simple material, is light and done by hand is usually made up by HELIX type probes. The objective is to cover an area in a minimum amount of time, the most amount of space in order to “orient” the possible prospection and be able to distinguish the richest areas in a mineralized sandy complex that will need to be studied in detail in a second phase. Given that they do not have a tube form, they will most likely not be able to reach the bed rock and will generally reach the piezometric level. This does not have a great deal of importance as soon as it has been seen that on the sands on the surface has generally gone through an Aeolic reclassification and are therefore enriched in heavy minerals as far as the deep levels are concerned.

Sampling mesh
The sampling mesh will be situated more or less around the following values:

• Distance in between lines: 1.000 to 1.500 meters.
• Distance in between well: 100 to 50 meters.

The distance between one well and another is due to the fact that the littoral formations is made up of bands that are some what parallel amongst each other and that generally do not pass through with the hundred width or a few hundred meters. It is considered that for an advantageous mechanization, (generally with a dredge), the width of these bodies should not be less than 70 to 80 meters.

Sampling methods
Sampling will need to be done meter by meter, all down the length of the drill. The samples that are obtained, through successive quarters, will be reduced to an equal weight of 100 grams and will be sent to the laboratory for the determination of the percentage of heavy minerals that are present.

Successive prospecting phases
Given that this is related to the semi systematic phase and systematic phase, as well as the cubage of the deposits, being made up of pretty particular methodologies, the study of a manual of mineral prospecting is advisable. it is pretty much enough to know that as far as the sampling is related, the work essentially consists on a shirking of the meshing in the following way:

• - In formations that are big in size and low tenors (recent littoral type formations, aeolic, or that of dunes).
• Distance between lines: 640 to 320 metres
• Distance between wells: 80 to 40 meters

• - In the well mineralized formations (ancient littoral type formations).
• Distance between lines: 320 to 160 or 80 meters
• Distance between wells: 40 to 20 or also 10 to 5 meters