Geo means 'earth', and 'ology' means study of. This is the simplest way to understand what the Geology is all about. However, that is a very simple way to define Geology which is actually a very complex science that involves the study of the complete make of the Earth.
The Earth is over 4.5 billion years old and it has gone through tremendous changes over these millions of years to be what as we see today. The Earth is made up of rocks containing silicon, iron, magnesium, aluminum, oxygen, sodium, potassium and other minerals. The Earth was formed approximately 4.5 billion years ago as a result of a supernova or what is a star explosion. However, the early Earth's atmosphere had no oxygen. There was no water on Earth as well. Studies suggest that the Earth got its own water from the leaching that happened from the rocks that formed the planet. Another theory suggests that comets and asteroids contain ice and if any comets or asteroids had collided with earth it could have delivered oceans worth of water. It is also believed that the eruption and the subsequent volcanic out gassing must have created the primordial atmosphere and then the oceans were formed. There was no oxygen when the Earth was formed; however it was far from lifeless. Researches’ are still underway as to who, the main biological players were in the pre-oxygen world, and researchers have been able to dig out clues from some of the oldest sedimentary rocks on the planet. Most of the scientist and researchers do believe that amount of atmospheric oxygen until 2.4 billion year ago was insignificant, till the Great Oxidization event occurred. They believe that there was a sudden spike in the levels of oxygen due to cynobacteria- photosynthesizing microbes that exhaled oxygen. How these cynobacteria appeared is pretty much uncertain. The Great Oxidization Event itself was pretty much complex with global freezing, mineral upheavals and the flourishing of new species. It is yet to be determined as to what the cause was and what the consequence really were.
Geology is typically divided into two categories: Physical Geology and Historical Geology.
Physical Geology is the branch that study's the earth's rocks, minerals and soil and how these have formed over billions of years. The internal process of how the tectonic plates moved and still move and how the mountains formed when pushed to the Earth's surface. Earthquakes, the result of the sudden movement of the crustal plates that release the internal energy that becomes pretty destructive at the surface. The internal molten heat and energy that get released through volcanic eruptions. The external behavior of the Earth like glaciations, flow of water, erosion, and weathering that have formed the landscapes that we know and see as the Earth's surface today.2300 years ago Aristotle, were amongst the first to try understand the working of this great planet and later during the 1600 and the 1700s, scientist studying the Earth believed that gigantic catastrophic events were the reasons behind the creation of the highest of mountains, deep oceans and canyons. Another concept was the law of superposition, study of the sequence of sedimentary rocks shows that each layer is younger than the layer below it and older than those above it. The Law of faunal succession also states that the fossils in these rocks also occur in the same sequence and changes in this fossil content represent the changes in time. In other words rocks from different parts of the world that contain the same type of fossils actually formed about the same time.
Historical Geology also known as Paleology is that part of Geology that uses the Geological principles and techniques to reconstruct and understand the geological history of the Earth. Historical Geology studies the geological processes that have changed the Earth's surface and way beneath the surface. there are several sub branches of geology that help in the process and they are stratigraphy or the branch that deals with study of the rock layers or strata as we call them and the stratification of the rocks or layering that has happened over billions of years. Then comes structural geology that is a branch that studies the three dimensional distribution of rock, and specifically with respect to the deformation that has happened over the years. Then there is Paleontology that tells the sequence of the events by studying the fossils and determines the evolution of different species, their interactions, nature of environment and also reasons for their extinction.
Geology as a subject is pretty vast and very intriguing. The scope of Geology is all encompassing. There is nothing in this world that is beyond the realm of Geology. The Water we drink, the energy that we cannot do without, food and the natural world, the natural hazards that can happen, every part of our lives are interlinked with Geology.
Geologists have a promising career in the fields of mining, petroleum, natural gas and precious metals. Apart from these the Geologist also work as researchers who work in the forefront of natural disaster prevention and management like predicting Tsunamis, Earthquakes, volcanoes etc.
There are several branches of Geology that one can choose from like Economic Geology, Engineering Geology, Geophysics, Geochemistry, Geochronology, Geomorphology, Hydrogeology, Marine Geology, Pedology etc.
Several colleges and Universities have both Undergraduate and Post Graduate courses in Geology. However, when in doubt it is always advisable to seek the advice of a career counselor so that one can make the right choice. There are several Career Counselors that one can go to including Online Career Counseling as well.
Apart from these there are many Career Guide Services available online and one can go through those websites to get a good understanding of the Course. Many Career seminars also are held to help students select the course most suitable for them. The counseling also helps students understand their strengths and weaknesses and can work accordingly to better themselves.
One can log on to the links listed below which will provide one with a good understanding of the courses available and how to go about cracking the exam:
By: Madhuchanda Saxena
Posted By - Assistant Editor