Earth Science, Geologic Time & Fossils, SMI-TAE
Planet Earth has billions of years of history, from the time when it was an inhospitable ball of hot magma to when its surface stabilized into a variety of diverse zones capable of supporting many life-forms. Many are the species that lived through the various geologic eras and left a trace of their existence in the fossils that we study today. But Earth is never done settling, as we can see from the earthquakes, tsunamis, volcanic eruptions, and other phenomena manifested in Earth’s crust, oceans, and atmosphere.
Earth Science, Geologic Time & Fossils Encyclopedia Articles By Title
smithsonite, zinc carbonate (ZnCO3), a mineral that was the principal source of zinc until the 1880s, when it was......
snow, the solid form of water that crystallizes in the atmosphere and, falling to the Earth, covers, permanently......
snow and ice climate, major climate type of the Köppen classification characterized by bitterly cold temperatures......
Snowball Earth hypothesis, in geology and climatology, an explanation first proposed by American geobiologist J.L.......
soil, the biologically active, porous medium that has developed in the uppermost layer of Earth’s crust. Soil is......
- Introduction
- Structure, Composition, Properties
- Nutrients, pH, Minerals
- Microbes, Nutrients, Erosion
- Formation, Composition, Structure
- Climate, Texture, Structure
- Formation, Composition, & Structure
- Texture, Structure, Composition
- FAO Groups, Texture, Structure
- Erosion, Conservation, Management
- Ecosystems, Nutrients, Structure
- Pollution, Contamination, Fertility
- Detoxification, Pathways, Microorganisms
soil chemistry, discipline embracing all chemical and mineralogical compounds and reactions occurring in soils......
soil liquefaction, ground failure or loss of strength that causes otherwise solid soil to behave temporarily as......
soil mechanics, the study of the physical properties and utilization of soils, especially used in planning foundations......
solar system, assemblage consisting of the Sun—an average star in the Milky Way Galaxy—and those bodies orbiting......
Solo man, prehistoric human known from 11 fossil skulls (without facial skeletons) and 2 leg-bone fragments that......
Solonchak, one of the 30 soil groups in the classification system of the Food and Agriculture Organization (FAO).......
Solonetz, one of the 30 soil groups in the classification system of the Food and Agriculture Organization (FAO).......
Henry Clifton Sorby was an English geologist whose microscopic studies of thin slices of rock earned him the title......
sorosilicate, any member of a group of compounds with structures that have two silicate tetrahedrons (each consisting......
South America, fourth largest of the world’s continents. It is the southern portion of the landmass generally referred......
- Introduction
- Geology, Plate Tectonics, Fossils
- Paleozoic, Fossils, Plate Tectonics
- Andes, Amazon, Galapagos
- Andes, Peaks, Glaciers
- Rivers, Amazon, Andes
- Lakes, Rivers, Wetlands
- Climate, Geography, Altitude
- Rainforest, Flora, Fauna
- Rainforests, Biodiversity, Ecosystems
- Tropical Forests, Biodiversity, Climate
- Wildlife, Ecosystems, Biodiversity
- Amazon Rainforest, Guianan Shield, Biodiversity
- Plains, Agriculture, Wildlife
- Indigenous, Cultures, Diversity
- Iberians, Indigenous, Colonization
- Population, Ecology, Distribution
- Languages, Dialects, Indigenous
- Demography, Fertility, Transition
- Population Growth, Migration, Poverty
- Oil, Gas, Coal
- Precious Metals, Gemstones, Mining
- Forestry, Fishing, Biodiversity
- Food Crops, Agriculture, Diversity
- Mining, Agriculture, Manufacturing
- Trade, Resources, Markets
- Transportation, Infrastructure, Trade
- Culture, Diversity, Traditions
South Pole, the southern end of the Earth’s axis, lying in Antarctica, about 300 miles (480 km) south of the Ross......
southern lights, luminous atmospheric display visible in the Southern Hemisphere. See...
Southern Oscillation, in oceanography and climatology, a coherent interannual fluctuation of atmospheric pressure......
Spalacotherium, extinct genus of primitive, probably predaceous, mammals known from fossils found in European deposits......
specific humidity, mass of water vapour in a unit mass of moist air, usually expressed as grams of vapour per kilogram......
speleology, scientific discipline that is concerned with all aspects of caves and cave systems. Exploration and......
sphalerite, zinc sulfide (ZnS), the chief ore mineral of zinc. It is found associated with galena in most important......
spherical Earth, refers to any figure of Earth as represented by a sphere. Although other models, including the......
spherulite, spherical body generally occurring in glassy rocks, especially silica-rich rhyolites. Spherulites frequently......
spilite, fine-grained or dense, extrusive igneous (volcanic) rock that is usually free of visible crystals and......
spiny shark, any of a group of more than 150 species of small extinct fishes traditionally classified in the class......
Spodosol, one of the 12 soil orders in the U.S. Soil Taxonomy. Spodosols are ashy gray, acidic soils with a strongly......
spreading centre, in oceanography and geology, the linear boundary between two diverging lithospheric plates on......
spring, in climatology, season of the year between winter and summer during which temperatures gradually rise.......
spring tide, tide of maximal range, near the time of new and full moon when the Sun and Moon are in syzygy—i.e.,......
squall, as used by weather forecasters, a sudden wind-speed increase of 8 metres per second (18 miles per hour)......
St. Swithin’s Day, (July 15), a day on which, according to folklore, the weather for a subsequent period is dictated.......
James Martin Stagg was a British meteorologist who, as the chief weather forecaster to General Dwight D. Eisenhower,......
standard atmosphere, atmospheric model with a given vertical distribution of temperature, pressure, and humidity,......
stannite, a sulfide mineral, chemical formula Cu2FeSnS4, that is an ore of tin. It is ordinarily found associated......
staurolite, silicate mineral [(Fe,Mg,Zn)3-4Al18Si8O48H2-4] produced by regional metamorphism in rocks such as mica......
stegosaur, any of the plated dinosaur species, including Stegosaurus and Tuojiangosaurus of the Late Jurassic period......
Steneosaurus, (genus Steneosaurus), extinct crocodiles that inhabited shallow seas and whose fossils are found......
Nicolaus Steno was a geologist and anatomist whose early observations greatly advanced the development of geology.......
stephanite, a sulfosalt mineral, silver antimony sulfide (Ag5SbS4), that occurs as black, lustrous, orthorhombic......
Balfour Stewart was a Scottish meteorologist and geophysicist noted for his studies of terrestrial magnetism and......
stibnite, antimony sulfide (Sb2S3), the principal ore of antimony. This mineral has a brilliant metallic lustre,......
Henry Melson Stommel was an American oceanographer and meteorologist. Stommel became internationally known during......
George Johnstone Stoney was a physicist who introduced the term electron for the fundamental unit of electricity.......
storm, violent atmospheric disturbance, characterized by low barometric pressure, cloud cover, precipitation, strong......
Strabo was a Greek geographer and historian whose Geography is the only extant work covering the whole range of......
John Strachey was an early geologist who was the first to suggest the theory of stratified rock formations. He......
stratification, the layering that occurs in most sedimentary rocks and in those igneous rocks formed at the Earth’s......
stratigraphy, scientific discipline concerned with the description of rock successions and their interpretation......
stratosphere, layer of Earth’s atmosphere lying between the troposphere and the mesosphere. The lower portion of......
stratospheric sulfur injection, untested geoengineering technique designed to scatter incoming solar radiation......
stratovolcano, volcanic landform characterized by a conical shape formed by layers of volcanic material deposited......
stratum, sedimentary rock layer bounded by two stratification planes, the latter being produced by visible changes......
streak, the colour of a mineral in its powdered form. It is usually obtained by rubbing the mineral on a hard,......
strengite, phosphate mineral similar to variscite (q.v.) with the chemical formula...
Streptelasma, extinct genus of corals, existing as single animals rather than colonial forms and found as fossils......
strike, in geology, direction of the line formed by the intersection of a fault, bed, or other planar feature and......
strike-slip fault, in geology, a fracture in the rocks of Earth’s crust in which the rock masses slip past one......
Stringocephalus, extinct genus of large brachiopods, or lamp shells, found as fossils in Devonian marine rocks......
stromatolite, layered deposit, mainly of limestone, formed by the growth of blue-green algae (primitive one-celled......
Stromatoporida, extinct order of corals found as fossils in marine rocks of Cambrian to Cretaceous age (542 million......
stromeyerite, a sulfide mineral of copper and silver (CuAgS) that occurs as compact masses with copper and lead......
strontianite, a strontium carbonate mineral (SrCO3) that is the original and principal source of strontium. It......
Stropheodonta, genus of small, extinct brachiopods (lamp shells) found as fossils in Devonian marine rocks (those......
Strophomena, genus of extinct brachiopods (lamp shells) found as fossils in Middle and Upper Ordovician marine......
structural geology, scientific discipline that is concerned with rock deformation on both a large and a small scale.......
Struthiomimus, (genus Struthiomimus), ostrichlike dinosaurs found as fossils from the Late Cretaceous Period (99......
stylolite, secondary (chemical) sedimentary structure consisting of a series of relatively small, alternating,......
subduction zone, oceanic trench area marginal to a continent in which, according to the theory of plate tectonics,......
subpolar gyre, an area of cyclonic ocean circulation that sits beneath a persistent region of low atmospheric pressure.......
subsidence, sinking of the Earth’s surface in response to geologic or man-induced causes. When subsidence occurs......
subsoil, Layer (stratum) of earth immediately below the surface soil, consisting predominantly of minerals and......
subtropical gyre, an area of anticyclonic ocean circulation that sits beneath a region of subtropical high pressure.......
subtropical high, one of several regions of semipermanent high atmospheric pressure located over the oceans between......
Sue, nickname for one of the most complete and best-preserved skeletons of Tyrannosaurus rex. The fossil was dated......
Eduard Suess was an Austrian geologist who helped lay the basis for paleogeography and tectonics—i.e., the study......
sulfate mineral, any naturally occurring salt of sulfuric acid. About 200 distinct kinds of sulfates are recorded......
sulfide mineral, any member of a group of compounds of sulfur with one or more metals. Most of the sulfides are......
sulfosalt, any of an extensive group of minerals, mostly rare species, marked by some of the most complicated atomic......
sulfur (S), nonmetallic chemical element belonging to the oxygen group (Group 16 [VIa] of the periodic table),......
Kathryn Sullivan is an American oceanographer and astronaut, the first American woman to walk in space (1984).......
summer, warmest season of the year, between spring and autumn. In the Northern Hemisphere, it is usually defined......
sun dog, atmospheric optical phenomenon appearing in the sky as luminous spots 22° on each side of the Sun and......
supercontinent, large landmass that accounts for the vast majority of Earth’s land. Some researchers argue that......
law of superposition, a major principle of stratigraphy stating that within a sequence of layers of sedimentary......
surge, in meteorology, an atmospheric process that operates on oceans and inland waters whereby a change in atmospheric......
sussexite, white to straw-yellow borate mineral, basic manganese borate [MnBO2(OH)]. Magnesium replaces manganese......
svabite, arsenate mineral, calcium fluoride arsenate [Ca5(AsO4)3F], in the apatite group of phosphates. Typical......
Harold Ulrik Sverdrup was a Norwegian meteorologist and oceanographer known for his studies of the physics, chemistry,......
syenite, any of a class of intrusive igneous rocks essentially composed of an alkali feldspar and a ferromagnesian......
sylvanite, a gold and silver telluride mineral [(Au,Ag)Te2] in which the ratio of gold to silver atoms is commonly......
sylvite, halide mineral, potassium chloride (KCl), the chief source of potassium. It is rarer than halite (sodium......
George James Symons was a British meteorologist who strove to provide reliable observational data by imposing standards......
szaibelyite, mineral composed of basic magnesium borate [MgBo2(OH)], similar to the manganese mineral sussexite...
Although his formal education occurred between the ages of 8 and 10, plus four or five years at medical school,......
Tabulata, major division of extinct coral animals found as fossils in Ordovician to Jurassic marine rocks (488......
Tabūn, site of paleoanthropological excavations in a deep rock shelter located on the edge of Mount Carmel and......
tachylyte, glassy igneous rocks low in silica, such as basalt or diabase. Tachylytes are black with a pitchlike......
taeniodont, any member of an extinct suborder (Taeniodonta) of mammals that lived in North America throughout the......
taenite, nickel-iron mineral having a face-centred cubic structure and playing a major role in the crystallization......