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The Job

The geologist's work includes locating and obtaining physical data and material. This may necessitate the drilling of deep holes to obtain samples, the collection and examination of the materials found on or under the earth's surface, or the use of instruments to measure the earth's gravity and magnetic field. Some geologists may spend three to six months of each year in fieldwork. In laboratory work, geologists carry out studies based on field research. Sometimes working under controlled temperatures or pressures, geologists analyze the chemical and physical properties of geological specimens, such as rock, fossil remains, and soil. Once the data is analyzed and the studies are completed, geologists and geological technicians write reports based on their research.

A wide variety of laboratory instruments are used, including X-ray diffractometers, which determine the crystal structure of minerals, and petrographic microscopes for the study of rock and sediment samples.

Geologists working to protect the environment may design and monitor waste disposal sites, preserve water supplies, and reclaim contaminated land and water to comply with federal environmental regulations.

Geologists often specialize in one of the following disciplines in the two main branches of the field: physical geology and historical geology.

Physical Geology

Economic geologists search for new resources of minerals and fuels. Petroleum geologists attempt to locate natural gas and oil deposits through exploratory testing and study of the data obtained. They recommend the acquisition of new properties and the retention or release of properties already owned by their companies. They also estimate oil reserves and assist petroleum engineers in determining exact production procedures.

Engineering geologists apply geological knowledge to problems arising in the construction of roads, buildings, bridges, dams, and other structures.

Environmental geologists study how pollution, waste, hazardous materials, and flooding and erosion affect the earth.

Geohydrologists, also known as hydrogeologists, study the nature and distribution of water within the earth and are often help conduct environmental impact studies.

Geomorphologists study the form of the earth's surface and the processes, such as erosion and glaciation, that bring about changes.

Geophysicists are concerned with matter and energy and how they interact. They study the physical properties and structure of the earth, from its interior to its upper atmosphere, including land surfaces, subsurfaces, and bodies of water.

Glacial geologists study the physical properties and movement of ice sheets and glaciers.

Marine geologists study the oceans, including the seabed and subsurface features. They are also known as geological oceanographers.

Mineralogists are interested in the classification of minerals composing rocks and mineral deposits. To this end, they examine and analyze the physical and chemical properties of minerals and precious stones to develop data and theories on their origin, occurrence, and possible uses in industry and commerce.

Petrologists study the origin of igneous, metamorphic, and sedimentary rocks.

Seismologists study earthquake shocks and their effects.

Structural geologists investigate the stresses and strains in the earth’s crust and the deformations they produce.

Volcanologists study volcanoes in an attempt to predict the potential for future eruptions and the impact eruptions may have on the welfare of humans, wildlife, and the environment.

The geologist is far from limited in a choice of work, but a basic knowledge of all sciences is essential in each of these specializations. An increasing number of scientists combine geology with detailed knowledge in another field. Geochemists, for example, are concerned with the chemical composition of, and the changes in, minerals and rocks, while planetary geologists apply their knowledge of geology to interpret surface conditions on other planets and the moon.

Historical Geology

Geochronologists are geoscientists who use radioactive dating and other techniques to estimate the age of rock and other samples from an exploration site.

Paleontologists specialize in the study of the earth's rock formations, including remains of plant and animal life, in order to understand the earth's evolution and estimate its age.

Sedimentologists, also known as sedimentary geologists, study sediments such silt, sand, and mud. These sediments often contain coal, gas, oil, and mineral deposits.

Closely related to sedimentologists, stratigraphers study the distribution and relative arrangement of sedimentary rock layers. This enables them to understand evolutionary changes in fossils and plants, which leads to an understanding of successive changes in the distribution of land and sea.

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