Introduction to Geology

What Is Geology?

Geology is that branch of science which deals with the earth as a whole regarding its history, composition, structure and day-to-day changes on surface as well as beneath the surface.

Its is derived from the Greek word: geo means earth and logos means science.
Earlier it was termed as Theology: theos means god and logos means science.

Systematic and scientific progress of geology started in 1776 (Independence of America).

In study of geology it requires to rely upon other basic branches. For example: Physics, Astronomy, Chemistry, Biology (Zoology and Botany).

Classification of Geology

The science of geology is vast subject but from engineering point of view the classification is

1. General Geology

2. Petrology

3. Engineering Geology

4. Indian Geology

1. General Geology: 

General geology is classified into three sub topics
1.a. The Restless Earth
1.b. Palanteology (study of fossils)
1.c. Mineralogy (study of minerals)

2. Petrology: 

It is derived from the Greek word petra and logos, petra meaning stone and logos meaning science. It is classified into three sub topics on basis of its origin

2.a. Igneous rocks

2.b. Sedimentary rocks

2.c. Metamorphic rocks

3. Engineering Geology: 

It is further divided into many sub topics

3.a. Physical geology:

It deals with various processes of physical agents. Example: wind, running water, glaciers and sea waves. These agents go on modifying surface of earth continuously. It includes study of erosion, transportation and deposition

3.b. Structural geology:

It deals with arrangement and architecture of rocks, which forms on earth crust. Used in selection of suitable sites for projects such as dams, tunnels, and multi-storey buildings.

3.c. Field geology:

It includes geological survey in field and interpretation in lab.

3.d. Hydrology:

It deals with occurrence and movement of water on surface of ground and under the ground.

3.e. Earth movements and Volcanic activities:

In this we study about the movement of tectonic plates, earthquakes theory of sea floor spreading, change in shape and size of plates etc.

3.f. Civil engineering Geology:

It is the youngest branch of geology, deals with geological implications along with suitable treatment arising in the field.

4. Indian Geology: 

It is classified as

4.a. Physiography of India

4.b. Stratigraphy of india

4.c. Coal and Petroleum

4.d. Economic minerals