Geology is one of the main branches of natural history. In its broadest sense, it is the study of the Earth—its interior and its exterior surface. It investigates the structure, evolution and dynamics of the Earth and its natural mineral and energy resources. Geology looks into the processes that have shaped the Earth throughout its history and uses the rock record to unravel that history. It examines the minerals, rocks and other materials that are around us, the water that flows over the surface and through the ground, the processes that have resulted in the formation of these materials, the changes that have taken place over time, and the changes that can be anticipated to occur in the future. The modern discipline of Geology is also known as geological science.
Even though classical geology is broad, embracing all the earth sciences, the modern academic discipline of geology tends to focus on the solid component of planet earth. This is owing to the rapid growth of scientific knowledge, which necessitates disciplines to narrow down their scope. As a result, several areas that were initially covered by geology have become separate independent fields of study. Nowdays, the term “earth science” or “geoscience” tends to be used to refer to geology and other fields of study that deal with some aspect of the earth.
Fields of geology
The modern discipline of geology has three major branches. They are physical geology, historical geology and environmental geology.
Physical geology
Physical geology studies the inorganic components and processes of the earth. It consists of numerous subfields. The following are some of them:
- Petrology.
- Mineralogy.
- Structural geology.
- Geomorphology.
- Volcanology.
- Sedimentology.
- Hydrogeology.
Historical geology
Historical geology deals with the past structure, composition and processes of the earth, from its creation to the present. The following are some of its major specializations:
- Stratigraphy.
- Paleontology.
- Geochronology.
Environmental geology
Environmental geology is an interdisciplinary study of the interactions of humans with the geological environment. The following are some of its major subfields:
- Natural hazards.
- Resource management.
- Waste management.
- Contaminant transport.
What do geologists do?
Geologists are employed in a diverse range of jobs in different industries, companies and organizations. Some work in the field, some in offices and others have a mixture of both. They are hired by public and private companies, international, governmental and nongovernmental organizations, commercial enterprises, and nonprofit asociations. The sectors they work in include mining, construction, engineering, energy, education, research, communications, environment, sanitation, the legal system, natural hazards and risk management, natural resources management, etc.
Below are some examples of the tasks that geologists carry out in their respective jobs:
- Geological field mapping: Examining the particular rock types and geological structures of an area and how they all relate to one another, and finally producing a geological map.
- Geological sampling exploration.
- Geotechnical mapping: assessing the engineering properties of a rock and its stability prior to undertaking any sort of construction or modification of the rocks (such as building a tunnel).
- Geological logging: This is often a field-based activity undertaken with geological drilling. Geologists describe rock extracted by drills to understand the geology below the surface. Logging of sedimentary or volcanic rocks above ground is also used to study past environmental changes or accurately record sampling locations. Some types of geological logging include the following:
- Rock core logging (or rock chip logging): This is essential for mining and exploration companies.
- Mud logging: This is vital for oil and gas exploration.
- Geotechnical logging: assessing how strong or weak rocks are below the ground using rock core.
- Laboratory work: Carrying out research and producing data that many companies and organizations such as mining, oil & gas, engineering and environmental companies can use. Laboratory work can include the following tasks:
- Microscope work: Examining very fine details of rocks and fossils using microscopes.
- Geochemical analyses: Using chemical methods to reveal details about samples (such as their metal content or the quality of oil).
- Geomechanical tests: Testing the strength of rocks.
- Computer-based work: All geologists will do a lot of their work on computer, often using specialist software. This can include:
- Geographical Information Systems (GIS): Essentially, this is geological field mapping on computers. It is about producing a digital database of the field data acquired by geologists.
- Database management.
- Modelling programs: For this geologists are trained in specialist software or programming. Geologists produce and maintain modelling computer programs for a range of purposes including:
- Modelling geological processes (often for research purposes).
- Producing a 3-D model of a mineral deposit, oil field or aquifer.
- Modelling the subsurface geology that an engineering project will modify.
- Writing reports: Summarising all their findings in a concise yet comprehensive manner is crucial for all scientists, and geologists are no different. Reports can be in the form of short daily updates or long articles and even books.
References
American Geosciences Institute. Geoscience Workforce. Retrieved from https://www.americangeosciences.org/workforce
Geological Society of London and University Geoscience UK. What is Geology? Retrieved from https://www.geolsoc.org.uk/Geology-Career-Pathways/What-is-Geology
Geological Society of London and University Geoscience UK. What do geologists do? Retrieved from https://www.geolsoc.org.uk/Geology-Career-Pathways/What-is-Geology/What-do-Geologists-do
Geological Society of London and University Geoscience UK. Job Sectors. Retrieved from https://www.geolsoc.org.uk/Geology-Career-Pathways/Careers/Job-Sectors
Indeed Editorial Team (2023) What Is a Geologist? (With Duties, Skills and Salary). Indeed.com India. Retrieved from https://in.indeed.com/career-advice/finding-a-job/what-is-a-geologist
Whittinghill, Kyle (2024) Introduction to Geology. In Environmental Science. Compiled by LibreTexts Project. University of Pittsburgh. Retrieved from https://bio.libretexts.org/Courses/University_of_Pittsburgh/Environmental_Science_(Whittinghill)/06%3A_Geology/6.01%3A_Introduction_to_Geology
Windley, Brian Frederick and Harbaugh, W. John (2024) Geology. Encyclopaedia Britannica. Retrieved from https://www.britannica.com/science/geology/Study-of-the-composition-of-the-Earth
U.S Bureau of Labor Statistics. Geoscientists. In Occupational Outlook Handbook. Retrieved from https://www.bls.gov/ooh/life-physical-and-social-science/geoscientists.htm#:~:text=Geologists%20study%20the%20materials%2C%20processes,to%20them%20since%20their%20formation.