Classifying the Alluvial
Deposits In General

The most rational classification of the alluvial deposits in general terms can be divided up into the following groups:

• Residual alluvium –Illuvial (atmospheric agents such as heat and cold) and Colluvial (agents such as the wind and glaciers – glaciers or dilluvials or aeolic)
• Transported alluvium – Fluvial – aluviums alluvial or proluvial – mountains
• Alluvial – high terraces and low ones
• Proluvial – double alluviums, triples and others.
• Sea or marine alluviums – submerged
• Fossil alluviums or buried
• Auriferous conglomerate

Residual alluvial deposits
These are accumulations in situ, generated by the mechanic weathering action; in other words, it can be found close to the original gradient, in the edges of the hills in form of debris as a consequence of the disintegration of the geological layers by the agents that have already been mentioned which are the heat and the cold. These deposits are denominated as eluvial and can be considered like an intermediate or embryonic phase in the formation of beach placers or those of fluvial.

Transported alluvium
These are deposits that can be found in the beds of the water currents or in the valleys, and are some of the most important deposits. These deposits are denominated as colluvial or dilluvials and these are defined as the clastic accumulations that come form the intermittent action of the water from melting ice, from the wind and gravity which have been transported through short distances. These deposits can be seen in a reduced form. Based on the type of people that have intervened in the formation of these deposits, they can be sub divided in glacial alluviums and aeolic.