Geology

Geology is the study of the Earth, its processes, its materials, its history, and its effect on humans and life in general.  Rocks, crystals, mountains, earthquakes, volcanoes, rivers, glaciers, landslides, floods, and many other subjects fall into this broad field of research.  Geologists perform a wide range of important services for our civilization: they determine the stability of building sites, find abundant supplies of clean water, search for valuable deposits of natural resources such as iron, coal, and oil, and they also try to minimize the threat to communities at risk from geologic hazards.

Geology is special in that it is a highly field-oriented science.  A geologist's work is usually outdoors, sometimes in out-of-the way places such as deserts or sparsely populated mountain ranges.  Some of the most geologically interesting places in the world are also the most scenic.  Students of geology can expect to find themselves working in locales that they have often wanted to travel to, as well as many that they had not known of but were grateful to have visited still.

Geology is a very visual science.  Many problems in geology are much like solving a puzzle.  A common task for students is to present a possible explanation of the events that occurred to produce the scenery surrounding them.  If you have ever wondered how a certain hill came to exist in a certain place, or why a cliff or canyon should have such a vivid display of color to it, or why a large outcrop of rock is exposed in a particular fashion, a background in geology can help you to return to those features and figure out the answers.  Once you have had an introduction to geology, you will see the world around you in a completely new light.

Origin

Geology is derived from the Greek γῆ, gê, meaning "earth" and λόγος, logos meaning "study". It is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which they change. Geology can also refer generally to the study of the solid features of any celestial body.

The Role of a Geologist

Geologists work to understand the history of our planet. The better they can understand Earth’s history the better they can foresee how events and processes of the past might influence the future. Here are some examples:

Geologists study earth processes:   Many processes such as landslides, earthquakes, floods and volcanic eruptions can be hazardous to people. Geologists work to understand these processes well enough to avoid building important structures where they might be damaged. If geologists can prepare maps of areas that have flooded in the past they can prepare maps of areas that might be flooded in the future. These maps can be used to guide the development of communities and determine where flood protection or flood insurance is needed.

Geologists study earth materials:   People use earth materials every day. They use oil that is produced from wells, metals that are produced from mines, and water that has been drawn from streams or from underground. Geologists conduct studies that locate rocks that contain important metals, plan the mines that produce them and the methods used to remove the metals from the rocks. They do similar work to locate and produce oil, natural gas and ground water.

Geologists study earth history:   Today we are concerned about climate change. Many geologists are working to learn about the past climates of earth and how they have changed across time. This historical geology news information is valuable to understand how our current climate is changing and what the results might be.

Types of Geology

Geology is a subject with many sub fields  It is a very wide academic discipline. The main branches of geography are mentioned below:

• Hydrogeology:  The branch of geology that deals with the occurrence, distribution, and effect of ground water. 

• Geophysics:   The physics of the earth and its environment, including the physics of the fields such as meteorology, oceanography, and seismology. 

• Geochemistry: The chemistry of the composition and alterations of the solid matter of the earth or a celestial body.  The study of the chemical composition and actual or possible chemical changes in the crust of the earth. 

• Oceanography:  The exploration and scientific study of the ocean and its phenomena. 

• Paleontology:  The study of the forms of life existing in prehistoric or geologic times, as represented by the fossils of plants, animals, and other organisms.  Specific study can entail vertebrate paleontology or invertebrate paleontology. 

• Petrology: The branch of geology that deals with the origin, composition, structure, and alteration of rocks. This branch is mainly concerned with the mineralogical and chemical composition of rocks, and with their classification: lithology. 

• Petroleum Geology: The branch of economic geology that deals with the occurrence and exploitation of oil and gas fields. 

• Sedimentary Geology: The branch of geology relating to rocks formed by the deposition of sediment. 

• Structural Geology:  The branch of geology relating to the structure of rocks and other aspects of the earth's crust.

Relative Dating

Relative dating is the science determining the relative order of past events, without necessarily determining their absolute age. In geology rock or superficial deposits, fossils and lithologies can be used to correlate one stratigraphic column with another. Prior to the discovery of radiometric dating which provided a means of absolute dating in the early 20th century, archaeologists and geologists were largely limited to the use of relative dating techniques to determine the geological events.

Absolute dating

Absolute dating is the process of determining an approximate computed age in archaeology and geology. Some scientists prefer the terms chronometric or calendar dating, as use of the word "absolute" implies an unwarranted certainty and precision. Absolute dating provides a computed numerical age in contrast with relative dating which provides only an order of events.

In archeology, absolute dating is usually based on the physical or chemical properties of the materials of artifacts, buildings, or other items that have been modified by humans. Absolute dates do not necessarily tell us precisely when a particular cultural event happened, but when taken as part of the overall archaeological record they are invaluable in constructing a more specific sequence of events.

Geology Mapping

A geologic map or geological map is a special-purpose map made to show geological features. Rock units or geologic strata are shown by color or symbols to indicate where they are exposed at the surface. Bedding planes and structural features such as faults, folds, foliations, and lineations are shown with strike and dip or trend and plunge symbols which give these features' three-dimensional orientations. Following are the different types of mapping:

Structural mapping: the locations of the major rock units and the faults and folds that led to their placement there.

Stratigraphic mapping: the locations of sedimentary facies (lithofacies and biofacies) or the mapping of isopachs of equal thickness of sedimentary rock

Surficial mapping: the locations of soils and surficial deposits

Geologic Materials

Geologic materials are the rocks and sediments that make up the land where we live. The characteristics of geologic materials reflect the processes that form them and the environments in which they form. Geologists divide these materials into three basic rock types.

Igneous rocks originate as extremely hot melted rock below the Earth's surface. If the melted rock cools slowly under the surface, it forms plutonic rock such as granite. If, instead, the melted rock stays hot and rises to the surface, it can either ooze out or explode to form volcanic rock, such as basalt and obsidian. When rocks get buried or are pushed deep into the Earth, the pressure and heat changes them into metamorphic rocks, such as marble and slate. Serpentinite, the California state rock, is another example of metamorphic rock. Sediments are mostly bits and pieces of older rocks that have been transported by wind and water to accumulate on beaches and in sand dunes, on lake and river bottoms, and on ocean floors. Given enough time, sediments may be buried under subsequent accumulations and then squeezed or cemented together to form sedimentary rocks, such as sandstone and shale. The remains of plants and animals get caught up in these accumulations to form fossils, which are found only in sediments and sedimentary rocks. Although fossils usually are sparse, a few sedimentary rocks are made almost entirely of fossils; for example, chert is made from millions of tiny plankton fossils.

Unconsolidated material

Geologists also study unlithified material, which typically comes from more recent deposits. Because of this, the study of such material is often known as Quaternary geology, after the recent Quaternary Period. This includes the study of sediment and soils, and is important to some (or many) studies in geomorphology, sedimentology, and paleoclimatology.

Applied Geology

Following are the different types of fields in applied Geology.

Economic geology : Economic geologists help locate and manage the Earth's natural resources, such as petroleum and coal, as well as mineral resources, which include metals such as iron, copper, and uranium.

Mining geology : Mining geology consists of the extractions of mineral resources from the Earth. Some resources of economic interests include gemstones, metals, and many minerals such as asbestos, perlite, mica, phosphates, zeolites, clay, pumice, quartz, and silica, as well as elements such as sulfur, chlorine, and helium.

Petroleum geology: Petroleum geologists study the locations of the subsurface of the Earth which can contain extractable hydrocarbons, especially petroleum and natural gas. Because many of these reservoirs are found in sedimentary basins,[52] they study the formation of these basins, as well as their sedimentary and tectonic evolution and the present-day positions of the rock units.

Engineering geology: Engineering geology is the application of the geologic principles to engineering practice for the purpose of assuring that the geologic factors affecting the location, design, construction, operation and maintenance of engineering works are properly addressed.

In the field of civil engineering, geological principles and analyses are used in order to ascertain the mechanical principles of the material on which structures are built. This allows tunnels to be built without collapsing, bridges and skyscrapers to be built with sturdy foundations and buildings to be built that will not settle in clay and mud.

Career

Geology is a multi-faced academic field with many different areas of specialization. The career options in Geology are many and lucrative. The importance of the subject and the demand for the geologists is increasing continuously all across the globe.  Over the next several years the number of geology job openings is expected to exceed the number of students graduating from university geology programs. The list of jobs available for a geology student is mentioned below.

•       Geoscientists
•       Wellsite Geologist
•       Hydrogeologist
•       Seismic Interpreter
•       Mudlogger
•       Geochemist
•       Engineering geologist
•       Geophysicist/field seismologist
•       Minerals Surveyor
•       Geophysical dataprocessor
•       Drilling Engineer
•       Environmental Consultant
•       Geology Educator
•       Science Writer/ Editor
•       Environmental Law

Where do geologists work?

•       Environmental consulting firms; 

•       Government — federal and state geological surveys and the Environmental Protection Agency, plus various other regulatory agencies that are mostly concerned with environmental matters; 

•       Oil and gas industry; 

•       Schools — junior high/high schools and colleges/universities; and 

•       Mining industry. 

Students with a broad interest in geology should pursue the Bachelor of Science degree in Geology, whereas those with interests in both environmental issues and geology may work toward a Bachelor of Science degree in Environmental Science following the "Geology Track". Students with both kinds of baccalaureate degrees are encouraged to pursue the Master of Science degree in Geology in order to acquire expertise in an area of specialization and so prepare themselves for a specific geological discipline and a better-paying job.