Preservation of a Placer Deposit

just about all of the eolian placers that are in the desert take place because of the bajada being augmented on the surface as a result of the action of the wind on the materials that gust off. There are a number of things that takes place to preserve a placer deposit. Because of the fact that streams are constantly altering their arrangements, remains of their deposits are left sheltered such as in the case of the terraces and beaches that are left at diverse periods when a stream is cutting into a channel that is deeper. The deposits that linger will sooner or later be tattered away unless something is shielding them. One way that a placer is preserved is when it is buried. For the most part this takes place when mudflows, lava, ash falls and so forth have sheltered a stream. Other ways this could happen are when:

• When there is a covering with gravel when the stream is obstructed.

• When there is a covering with lake deposits.

• When there is a covering with gravel.

• When there is a covering by the material of a landslide.

• When there is a covering with gravel when the course of the stream goes down under the normal base level of wearing down

• When there is a covering of an older stream course with alluvial fan matter as conditions that favour the stream to exist do not succeed.

• When there is covering with glacial till.

• When there is a covering of beach placers with sediments from the sea as the coast is flooded and elevated.