Geologists, geochemists and geophysicists conduct theoretical and applied research to extend knowledge of surface and subsurface features of the earth, its history and the operation of physical, chemical and biological systems that control its evolution.
Geologists, geochemists and geophysicists conduct programmes of exploration and research to extend knowledge of the structure, composition and processes of the earth and to locate and identify hydrocarbon, mineral and groundwater resources. They also plan and implement programmes of hydrocarbon and mineral extraction, and they assess and mitigate the effects of development and waste disposal projects on the environment.
These scientists plan, direct and participate in geological, geochemical and geophysical field studies, drilling and geological testing programs, and seismic, electromagnetic, magnetic, gravimetric, radiometric, radar and other remote sensing programmes. They also plan, direct and participate in the analysis of geological, geochemical and geophysical survey data, the analysis of core samples, drill cuttings and rock samples in order to identify chemical, mineral, hydrocarbon and biological composition, and also the analysis of well logs, other test results, maps, notes and cross-sections.
They develop applied software for the analysis and interpretation of data. They assess depositional environments and geological age, and they assess the size, orientation and composition of mineral ore bodies and hydrocarbon deposits.
They also identify deposits of construction materials and determine their characteristics and suitability for use as concrete aggregates, road fill or other applications. They assess the movement of ground and surface waters, and they advise in areas such as waste management, route and site selection, and the restoration of contaminated sites.
They recommend the acquisition of land, exploration and mapping programmes, and mine development, and they conduct geological and geophysical studies for regional development, site selection and the development of public works projects.
They identify and anticipate natural risks, such as slope erosion, landslides, soil instability, subsidence, earthquakes and volcanic eruptions, and they may supervise and coordinate well drilling, completion and work-over, as well as mining activities.
Geological research helps in locating mineral deposits, predicting earthquakes, and advising on the suitability of sites for buildings, dams and highways. The knowledge obtained is also used in a wide variety of ways, from determining the components of plaster on walls of buildings where lime and other mixtures are used, to the discovery and refinement of oil and other energy sources.
Geology is a very broad-based science, which draws from virtually every other science including the natural, engineering and economic sciences. There are various careers within the field of geology, for example: cartography, economic geology, environmental geology, engineering geology, geochemistry, geotechnology, geohydrology, geophysics, mineralogy, mining geology, palaeontology, petroleum geology.
The broad areas of specialisation within this field include: earth material; earth processes and earth history. The sub-specialities include: economic geology, mineralogy, geochemistry, geophysics, palaeontology, marine geology, mineral economics, engineering geology and environmental planning.
General geologists can specialise in various fields of application, of which only a few are discussed here:
Basic mapping is the drawing of a map on which geological information such as the distribution of different rocks is shown. This is one of the most important tasks of geologists.
Economic geology studies the deposit of economic minerals and processes leading to their formation.
Environmental geology studies recent sediments deposited in river valleys, on beaches and in the oceans, in order to acquire information on aspects such as climatic changes, erosion of coastlines and the influence of human activities on the environment.
Geological engineers study the physical and chemical properties of rocks and soil in order to ensure that dams, road, tunnels and buildings are built at the most suitable sites and in the most cost-effective manner. They also study materials used in road construction.
Geohydrologists study the water-storing capacity of various geological formations and the flow of groundwater in these formations. The development of cavities in rocks through cracks and faults as well as the chemical solution of rocks are also studied by geohydrologists. Post-graduate study and specialisation at an honours degree level is essential for a career as geohydrologist.
Palaeontologists study fossils to make deductions concerning the climate that prevailed during deposition and the environment where the organisms occurred. This information is used amongst other things, to understand the origin and formation of certain minerals in sedimentary rocks and to find further resources. The study of fossils also contributes to our knowledge of factors that led to species extinction and the origin of new species.
Geologists work in a variety of settings. They may work outdoors at a site under investigation, with conditions varying from sub-zero temperatures to the scorching heat in a desert. In addition, they may work indoors in laboratories, offices and classrooms.