GEOLOGY NAT SCI 1 1232020 1 Geology Definition

GEOLOGY NAT. SCI. 1 12/3/2020 1

Geology: Definition Geology is the study of the planet earth, its rocky exterior, its history, and the processes that act upon it. Geology is also referred to as earth science and geoscience. 12/3/2020 2

Geology: Definition The word geology comes from the Greek geo, “earth, ” and logia, “the study of. ” Geologists seek to understand how the earth formed and evolved into what it is today, as well as what made the earth capable of supporting. 12/3/2020 3

Geology: Branches o PHYSICAL GEOLOGY §Geophysics § Geochemistry § Mineralogy § Structural Geology § Hydrology and Geomorphology § Marine Geology § Environmental, Economic, and Engineering Geology 12/3/2020 4

Geology: Branches o HISTORICAL GEOLOGY § Stratigraphy § Sedimentology § Geochronology § Paleontology and Paloebiology § Paleoceanography and Paleoclimatology 12/3/2020 5

Geology: Branch Description q GEOPHYSICS In the field of geophysics, geologists apply the concepts of physics to the study of the earth. Geophysics is such a broad field that scientists sometimes consider it a separate field from geology. The largest subdiscipline in geophysics is seismology, the study of the travel of seismic waves through the Earth. 12/3/2020 6

Geology: Branch Description q GEOCHEMISTRY Geochemistry is the application of chemistry to the study of the earth, its materials, and the cycling of chemicals through its systems. Geochemistry is important for tracing the transport of chemicals through the earth’s four component systems: the lithosphere (rocky exterior), the hydrosphere (waters of the earth), the atmosphere (air), and the biosphere (the system of living things). 12/3/2020 7

Geology: Branch Description q MINERALOGY AND PETROLOGY The fields of mineralogy (the study of minerals) and petrology (the study of rocks) are closely related because rocks are made of minerals. Mineralogists and petrologists study the origin, occurrence, structure, and history of rocks or minerals. They attempt to understand the physical, chemical, and less commonly, biological conditions under which geologic materials form. 12/3/2020 8

Geology: Branch Description q STRUCTURAL GEOLOGY Structural geology deals with the form, arrangement, and internal structure of rocks, including their history of deformation, such as folding and faulting. Structural geology includes everything from field mapping to the study of microscopic deformation within rocks. Most geologic reconstructions require an 12/3/2020 9

Geology: Branch Description q HYDROLOGY AND GEOMORPHOLOGY The earth's surface processes are the focus of hydrology and geomorphology. Hydrology is the study of water on the earth's surface, excluding the oceans. Geomorphology is the examination of the development of present landforms; geomorphologists attempt to understand the nature and origin of these landforms 12/3/2020 10

Geology: Branch Description q MARINE GEOLOGY Geology specific to the ocean environment is called marine geology. Marine geologists may be specialists in a number of fields, including petrology, sedimentology, stratigraphy, paleontology, geochemistry, geophysics, and volcanology. They may take samples from the ocean while out at sea or make measurements through remote sensing techniques. 12/3/2020 11

Geology: Branch Description q ENVIRONMENTAL, ECONOMIC, AND ENGINEERING GEOLOGY The application of geologic knowledge to practical problems is the focus of the fields of environmental, economic, and engineering geology. 12/3/2020 12

Geology: Branch Description q ENVIRONMENTAL, ECONOMIC, AND ENGINEERING GEOLOGY Environmental geology involves the protection of human health and safety through understanding geological processes. For example, it is critically important to understand the geology of areas where people propose to store nuclear waste products. 12/3/2020 13

Geology: Branch Description q ENVIRONMENTAL, ECONOMIC, AND ENGINEERING GEOLOGY Economic geology is the use of geologic knowledge to find and recover materials that can be used profitably by humans, including fuels, ores, and building materials. 12/3/2020 14

Geology: Branch Description q ENVIRONMENTAL, ECONOMIC, AND ENGINEERING GEOLOGY Engineering geology is the application of engineering principles to geologic problems. Two fields of engineering that use geology extensively are civil engineering and mining engineering. For example, the stability of a building or bridge requires an understanding of both the foundation material (rocks, soil) and the potential for earthquakes in the area. 12/3/2020 15

Geology: Branch Description q STRATIGRAPHY Stratigraphy is the study of the history of the earth's crust, particularly its stratified (layered) rocks. Stratigraphy is concerned with determining age relationships of rocks as well as their distribution in space and time. 12/3/2020 16

Geology: Branch Description q SEDIMENTOLOGY Sedimentology, or sedimentary geology, is the study of sediments and sedimentary rocks and the determination of their origin. Sedimentary geology is process oriented, focusing on how sediment was deposited. Sedimentologists are geologists who attempt to interpret past environments based on the observed characteristics, called facies, of sedimentary rocks. 12/3/2020 17

Geology: Branch Description q GEOCHRONOLOGY The determination of the age of rocks is called geochronology. The fundamental tool of geochronology is radiometric dating (the use of radioactive decay processes as recorded in earth materials to determine the numerical age of rocks). Most radiometric dating techniques are useful in dating igneous and metamorphic rocks and minerals. One type of nonradiometric dating, called strontium isotope dating, measures different forms of the element strontium in sedimentary materials 12/3/2020 to date the layers. 18

Geology: Branch Description q PALEONTOLOGY AND PALOEBIOLOGY Paleontology is the study of ancient or fossil life. Paleobiology is the application of biological principles to the study of ancient life on earth. These fields are fundamental to stratigraphy and are used to reconstruct the history of organisms' evolution and extinction throughout earth history. 12/3/2020 19

Geology: Branch Description q PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY Paleoceanography (the study of ancient oceans) and paleoclimatology (the study of ancient climates) are two subfields that use fossils to help reconstruct ancient conditions. Scientists also study stable isotopes, or different forms, of oxygen to reconstruct ancient temperatures. They use carbon and other chemicals to reconstruct aspects of ancient oceanographic and climatic conditions. 12/3/2020 20

THE END. THANKS. 12/3/2020 21