Foundation, Concrete and Earthquake Engineering

Glacial Action and Deposition of Loess Soil

The reader we have discussed few topics about loess soil in our previous posts; here you will learn early deposition of loess after Ice Age.

This is about 2.6 million years ago, the ice is began which is also known as glacial age. In this period the most portion of earth was covered with glaciers. After glacial age, the climate began to warm up which leads to melting of hard ice and melted glaciers produced tremendous water to flow down into nearby rivers or valleys.

This process left a huge plain of mud to expose. In course of time, the plain became dry and exposed to action of wind. These sediments were blown with strong winds.
Dust storm form Tasman Glacier which form Christchurch loess soil
Now how is loess related to glacial action?

When the pulverized inert particles of size of silt produced with glacial action is peaked up by wind and blown from flood plain, loess are formed as a deposition of Aeolian soil.

Now we will know about deposition environment of loess. When adequate humidity in the ambient air was available the grains of a wind transported soil get precipitated. The sources of humidity were either

a. Glacial out wash

b. Or Flowing stream

It is observed in many loess soils that several depositions of loess are staked upon top of other loess deposition. This is due to individual glacial action of several glacier of a region.

These loessial top soils are found in many reasons of the world like

1. Central United States

2. Northwest of United States

3. Central Europe

4. Eastern Europe

5. Eastern China

In our upcoming posts we will discuss about distribution of loess deposition over the world.

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