What is Geology?
Geology is the study of the earth. It looks into how the earth was formed, its structure, composition, and the types of processes acting on it. Geology is also known as geoscience or earth science.
Geology includes studying natural things found on earth, like mountains, rocks, oceans, crust, deserts, rivers, and other natural phenomena.
Physical geology is a super-discipline that overlaps other disciplines like geophysics, geochemistry, petrology, mineralogy, geomorphology, and structural geology.
Physical geology also examines land use, pollution, volcanoes, and earthquakes.
Historical geology or palaeogeology is the study of principles and methods of geology to reconstruct the geological history of the earth. Historical geology studies the vastness of geological time and investigates changes in the earth. It includes all the gradual and sudden changes.
It includes the study of fossils, rock strata, and ancient events that took place on earth and changed the environment. Historical geology also studies geological formations and how they were formed.
Basic Differences Between Physical & Historical Geology
Here are the key differences between physical and historical differences.
- Physical geology deals with the study of earth’s current surface and the formation of crust, rock cycle, and their formation whereas historical geology deals with the origin of the earth, the changes in its structure over a particular time period or from the origin. It also deals with the evolution of life that has been changed through a particular duration.
- The geologists study the rock cycle and their formation in physical geology. They explore different types of rocks, material, formation, shapes, and different structure while the geologists in historical geology explore the change in the rock structures and the formation of new rocks, the disappearance of ancient rocks over the time.
- The physical geology deals with the ocean cycle, the deposition, superposition, transgression and regression processes of natural phenomena whereas; the historical geology deals with the comparison of ocean cycles in the past and now. It also explores the answers to the questions why, when and how the natural phenomena like rain, wind, and water contributed to change the structure of earth over time.
- In physical geology, we study the volcano and lavas that are changing the structure of the earth while in historical geology, we observe the previously occurred volcano and the formation of lava million years ago.
- Same as above, the physical geology stresses upon the facts regarding the deserts, their structure, formation, natural factors contributing to changing the desert structures currently. However, in historical geology, we are particularly concerned with the historical events that took part in the appearance and disappearance of deserts on the surface of earth.
Let’s consider the example of Sahara desert. In physical geology, the geologists will argue the constituents, the rocks of Sahara and the phenomena that take part in changing the atmosphere of Sahara. In historical geology, the geologists will try to explore how it appeared to the surface of Earth. It can be done by examining the fossils found from Sahara. They will argue, what were the factors that made it appear on earth and when and how it came into existence.
So, physical and historical geology are the two main branches of geology. But they deal with geology in a totally different way. The area of research in both branches is different. Physical geology is concerned with the current time geo structure and the geologists examine the current structure of natural phenomena such as rocks, erosion, earthquake, tectonic plates, oceans, wind and crust of the earth. But historical geology is the study of the history of geo structure over time and the geologists examine the fossils of the animals and other natural aspects to know their origin and history.