Earth Science, Geologic Time & Fossils, DIA-EUR
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
diastrophism
diastrophism, large-scale deformation of Earth’s crust by natural processes, which leads to the formation of continents......
Dictyoclostus
Dictyoclostus, genus of extinct brachiopods, or lamp shells, that were common invertebrate forms in the shallow......
Dicuil
Dicuil was a monk, grammarian, and geographer whose work is important to the history of science and is a testament......
Did Dinosaurs Really Have Feathers?
Science is learning more and more about the versatility of form in dinosaurs with each great find in China, the......
Did Humans Live at the Same Time as Dinosaurs?
TV shows such as The Flintstones depict humans and dinosaurs living together in harmony. But that’s just fiction,......
Didymograptus
Didymograptus, genus of graptolites (an extinct group of colonial animals related to primitive chordates) found......
Dielasma
Dielasma, genus of extinct brachiopods, or lamp shells, that occur as fossils in rocks deposited in marine environments......
Dietz, Robert S.
Robert S. Dietz was an American geophysicist and oceanographer who set forth a theory of seafloor spreading in......
dike
dike, in geology, tabular or sheetlike igneous body that is often oriented vertically or steeply inclined to the......
Dikelocephalus
Dikelocephalus, genus of trilobites (extinct arthropods) that is a useful guide fossil for the Late Cambrian rocks......
Dimetrodon
Dimetrodon, (genus Dimetrodon), extinct relative of primitive mammals that is characterized by a large, upright,......
Dimorphodon
Dimorphodon, (genus Dimorphodon), primitive flying reptiles found as fossils in European deposits from the Early......
Dines, William Henry
William Henry Dines was a British meteorologist who invented instruments to measure atmospheric properties. The......
Dinichthys
Dinichthys, extinct genus of arthrodires, i.e., primitive, armoured, fishlike animals known as placoderms that......
dinosaur
dinosaur, (clade Dinosauria), the common name given to a group of reptiles, often very large, that first appeared......
- Introduction
- Evolution, Classification, Extinction
- Archosaurs, Reptiles, Triassic
- Extinction Causes, Evidence, & Theory
- Asteroid Theory, Extinction, Fossils
- Extinction, Fossils, Evolution
- Herding, Socialization, Adaptation
- Endothermic, Thermoregulation, Homeothermy
- Reptiles, Extinction, Fossils
- Sauropods, Herbivores, Quadrupeds
- Theropods, Extinction, Fossils
- Tetanurae, Reptiles, Extinction
- Ornithischia, Herbivore, Reptile
- Pachycephalosaurs, Head-Butting, Herbivores
- Armored, Herbivorous, Ornithischians
- Armored, Herbivorous, Extinct
Dinosaur National Monument
Dinosaur National Monument, desert area in northwestern Colorado and northeastern Utah, U.S., set aside in 1915......
Dinosaur Provincial Park
Dinosaur Provincial Park, public park located in the badlands of southeastern Alberta, Canada. The nearly 29-square-mile......
dinosauromorph
dinosauromorph, any of a group of archosaurian reptiles that includes dinosaurs and all other reptiles bearing......
diorite
diorite, medium- to coarse-grained intrusive igneous rock that commonly is composed of about two-thirds plagioclase......
dip circle
dip circle, instrument for measuring the inclination, or dip, of the Earth’s magnetic field. It consists essentially......
dip pole
dip pole, any point on the Earth’s surface where the dip (magnetic inclination; i.e., the angle between the Earth’s......
Diplograptus
Diplograptus, genus of graptolites, small, extinct colonial marine animals thought to be related to the primitive......
Diplovertebron
Diplovertebron, genus of extinct amphibians of North America and Europe known from fossils in Late Carboniferous......
dipolar hypothesis
dipolar hypothesis, theory that the Earth’s magnetic field is produced or is best represented by a magnetic dipole,......
Diprotodon
Diprotodon, extinct genus of marsupial classified in the suborder Vombatiformes and considered to be the largest......
Dipterus
Dipterus, genus of very primitive lungfish, among the earliest known, found as fossils in European and North American......
dire wolf
dire wolf, (Aenocyon dirus), canine that existed during the Pleistocene Epoch (2.6 million to 11,700 years ago).......
Docodon
Docodon, extinct genus of mammals originally known only from fossilized teeth. The dentition patterns of the cusps......
Does it rain on other planets?
Unlike Earth, where water falls as rain, other planets in our solar system experience vastly different precipitation.......
Dollond, George
George Dollond was a British optician who invented a number of precision instruments used in astronomy, geodesy,......
Dolomieu, Dieudonné
Dieudonné Dolomieu was a French geologist and mineralogist after whom the mineral dolomite was named. A member......
dolomite
dolomite, type of limestone, the carbonate fraction of which is dominated by the mineral dolomite, calcium magnesium......
domeykite
domeykite, a copper arsenide mineral (formulated Cu3As) that is often intergrown with algodonite, another copper......
Doria, Giacomo
Giacomo Doria was an Italian naturalist and explorer who in 1867 founded the civic museum of natural history in......
Douglas scale
Douglas scale, either of two arbitrary series of numbers from 0 to 9, used separately or in combination to define......
Drizzle
Drizzle, very small, numerous water drops that may appear to float while being carried by air currents; drizzle......
drought
drought, lack or insufficiency of rain for an extended period that causes a considerable hydrologic (water) imbalance......
Dryopithecus
Dryopithecus, genus of extinct ape that is representative of early members of the lineage that includes humans......
Duchesne, André
André Duchesne was a historian and geographer, sometimes called the father of French history, who was the first......
dunite
dunite, light yellowish green, intrusive igneous ultramafic rock that is composed almost entirely of olivine. Dunite......
duricrust
duricrust, surface or near-surface of the Earth consisting of a hardened accumulation of silica (SiO2), alumina......
Durisol
Durisol, one of the 30 soil groups in the classification system of the Food and Agriculture Organization (FAO).......
Dust
Dust, in general, any microscopic, powderlike particle or collection of powderlike particles that is made up of......
Dutton, Clarence Edward
Clarence Edward Dutton was an American geologist and pioneer seismologist who developed and named the principle......
dynamo theory
dynamo theory, geophysical theory that explains the origin of Earth’s main magnetic field in terms of a self-exciting......
E region
E region, ionospheric region that generally extends from an altitude of 90 km (60 miles) to about 160 km (100 miles).......
Earle, Sylvia
Sylvia Earle is an American oceanographer and explorer known for her research on marine algae and her books and......
Earth
Earth, third planet from the Sun and the fifth largest planet in the solar system in terms of size and mass. Its......
Earth sciences
Earth sciences, the fields of study concerned with the solid Earth, its waters, and the air that envelops it. Included......
- Introduction
- Prehistoric, Origins, Geology
- Nile Origin, Geology, Hydrology
- Paleontology, Stratigraphy, Geology
- Evaporation, Oceans, Climate
- William Smith, Faunal Succession
- Geologic Time, Age, Earth
- Hydrology, Water Cycle, Groundwater
- Clouds, Fog, Dew
- Radiometric Dating
- Plate Tectonics, Geology, Geophysics
- Desalination, Tidal Power, Minerals
- Atmosphere, Climate, Weather
- Weather Modification, Climate Change, Atmospheric Science
Earth, geologic history of
geologic history of Earth, evolution of the continents, oceans, atmosphere, and biosphere. The layers of rock at......
earthquake
earthquake, any sudden shaking of the ground caused by the passage of seismic waves through Earth’s rocks. Seismic......
- Introduction
- Tectonics, Seismology, Faults
- Volcanism, Seismology, Tectonics
- Seismic Waves, Faulting, Ground Shaking
- Magnitude, Intensity, Effects
- Magnitude, Seismology, Epicenter
- Shallow, Intermediate, Deep Foci
- Seismic Waves, Properties, Geology
- Seismology, Epicenters, Magnitude
- Reducing Hazards
- Magnitude, Epicenters, Destruction
ebb tide
ebb tide, seaward flow in estuaries or tidal rivers during a tidal phase of lowering water level. The reverse flow,......
Echinosphaerites
Echinosphaerites, genus of cystoids, an extinct group related to the sea lily and starfish, found as fossils in......
Eckener, Hugo
Hugo Eckener was a German aeronautical engineer and commander of the first lighter-than-air aircraft to fly around......
eclogite
eclogite, any member of a small group of igneous and metamorphic rocks whose composition is similar to that of......
economic geology
economic geology, scientific discipline concerned with the distribution of mineral deposits, the economic considerations......
Edaphosaurus
Edaphosaurus, (genus Edaphosaurus), primitive herbivorous relative of mammals that is found in fossil deposits......
Ediacara fauna
Ediacara fauna, unique assemblage of soft-bodied organisms preserved worldwide as fossil impressions in sandstone......
Ehrenberg, Christian Gottfried
Christian Gottfried Ehrenberg was a German biologist, microscopist, scientific explorer, and a founder of micropaleontology—the......
Ehringsdorf remains
Ehringsdorf remains, human fossils found between 1908 and 1925 near Weimar, Germany. The most complete fossils......
Ekman layer
Ekman layer, a vertical region of the ocean affected by the movement of wind-driven surface waters. This layer,......
Ekman spiral
Ekman spiral, theoretical displacement of current direction by the Coriolis effect, given a steady wind blowing......
El Niño
El Niño, in oceanography and climatology, the anomalous appearance, every few years, of unusually warm ocean conditions......
Electrojet
Electrojet, streaming movement of charged particles in the lower ionosphere. The term is limited by some to those......
electrum
electrum, natural or artificial alloy of gold with at least 20 percent silver, which was used to make the first......
elephant bird
elephant bird, (family Aepyornithidae), any of several species of extinct giant flightless birds classified in......
eluviation
eluviation, Removal of dissolved or suspended material from a layer or layers of the soil by the movement of water......
Enaliarctos
Enaliarctos, extinct genus of mammals that contains the oldest known member of Pinnipedia, the group that contains......
enargite
enargite, sulfosalt mineral, copper arsenic sulfide (Cu3AsS4), that is occasionally an important ore of copper.......
Endothyra
Endothyra, extinct genus of Foraminifera, protozoans with a readily preservable shell; found as fossils in Devonian......
Engelmann, George
George Engelmann was a U.S. botanist, physician, and meteorologist who is known primarily for his botanical monographs,......
engineering geology
engineering geology, the scientific discipline concerned with the application of geological knowledge to engineering......
Entisol
Entisol, one of the 12 soil orders in the U.S. Soil Taxonomy. Entisols are soils defined by the absence or near......
environmental geology
environmental geology, field concerned with applying the findings of geologic research to the problems of land......
Eohippus
Eohippus, (genus Hyracotherium), extinct group of mammals that were the first known horses. They flourished in......
eolian sound
eolian sound, sound produced by wind when it encounters an obstacle. Fixed objects, such as buildings and wires,......
eon
eon, Long span of geologic time. In formal usage, eons are the longest portions of geologic time (eras are the......
Eospermatopteris
Eospermatopteris, genus of extinct plants known from fossil stumps discovered in the 1870s near Gilboa, New York,......
Eospirifer
Eospirifer, genus of extinct brachiopods, or lamp shells, found as fossils in Middle Silurian to Lower Devonian......
epicentre
epicentre, point on the surface of the Earth that is directly above the underground point (called the focus) where......
epidote-amphibolite facies
epidote-amphibolite facies, one of the major divisions of the mineral-facies classification of metamorphic rocks,......
epoch
epoch, unit of geological time during which a rock series is deposited. It is a subdivision of a geological period,......
epsomite
epsomite, a common sulfate mineral, hydrated magnesium sulfate (MgSO4·7H2O). Its deposits are formed by evaporation......
Equator
Equator, great circle around Earth that is everywhere equidistant from the geographic poles and lies in a plane......
Equatorial countercurrent
Equatorial countercurrent, current phenomenon noted near the equator, an eastward flow of oceanic water in opposition......
Equatorial current
Equatorial current, ocean current flowing westward near the equator, predominantly controlled by the winds. Characteristically,......
Equatorial front
Equatorial front, zone near the Equator in which the trade winds of the two hemispheres meet. The designation (about......
era
era, a very long span of geologic time; in formal usage, the second longest portions of geological time (eons are......
Eratosthenes
Eratosthenes was a Greek scientific writer, astronomer, and poet, who made the first measurement of the size of......
erosion
erosion, removal of surface material from Earth’s crust, primarily soil and rock debris, and the transportation......
Eryops
Eryops, genus of extinct primitive amphibians found as fossils in Permian rocks in North America (the Permian period......
erythrite
erythrite, arsenate mineral in the vivianite group, hydrated cobalt arsenate [Co3(AsO4)2·8H2O]. Erythrite, which......
Espy, James Pollard
James Pollard Espy was an American meteorologist who apparently gave the first essentially correct explanation......
essexite
essexite, dark gray to black, fine-grained, intrusive igneous rock that occurs in Essex County, Mass.; at Mount......
eucrite
eucrite, rock that contains 30 to 35 percent calcium-rich plagioclase feldspar (bytownite or anorthite), as well......
Euparkeria
Euparkeria, extinct genus of reptile very closely related to the ancestral archosaurs (a group containing present-day......
Euphemites
Euphemites, extinct genus of gastropods (snails) abundant during the Late Carboniferous Period (between 320 and......
Eurasia
Eurasia, geological and geopolitical term that relates in the former sense to the single enormous landmass composed......
Europasaurus
Europasaurus, genus representing one of the smallest known sauropod dinosaurs, characterized by a distinctive arched......
Europe
Europe, second smallest of the world’s continents, composed of the westward-projecting peninsulas of Eurasia (the......
- Introduction
- Geology, Tectonics, Plate Boundaries
- Hercynian, Orogenic, Belt
- Cenozoic, Igneous, Provinces
- Geography, Climate, People
- Mediterranean, Balkan, Iberian
- Climate, Regions, Weather
- Flora, Fauna, Ecosystems
- Wildlife, Fauna, Ecosystems
- Migration, Ethnicity, Religion
- Religions, Faiths, Beliefs
- Trade, Manufacturing, Services
- Resources, Power, Geography
- Manufacturing, Industries, Trade
- Tourism, Culture, History