Earth Science, Geologic Time & Fossils, LIM-MET
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
limnology
limnology, subsystem of hydrology that deals with the scientific study of fresh waters, specifically those found......
Limnoscelis
Limnoscelis, extinct genus of tetrapod that appeared very close to the origin of amniotes (mammals, birds, or reptiles).......
Lindgren, Waldemar
Waldemar Lindgren was a Swedish-born American economic geologist noted for a system of ore classification that......
linnaeite
linnaeite, a cobalt sulfide mineral (Co3S4) or any member of a series of similar substances with the general formula......
Linoproductus
Linoproductus, genus of extinct articulate brachiopods (lamp shells) found throughout the midcontinent region of......
Lipalian interval
Lipalian interval, in geology, time span suggested in an attempt to explain the sudden appearance of abundant life......
Lisbon earthquake of 1755
Lisbon earthquake of 1755, series of earthquakes that occurred on the morning of Nov. 1, 1755, causing serious......
litharge
litharge, one of two mineral forms of lead(II) oxide (PbO). It is found with the other form, massicot, as dull......
lithification
lithification, complex process whereby freshly deposited loose grains of sediment are converted into rock. Lithification......
lithiophilite
lithiophilite, common phosphate mineral [LiMnPO4] similar to triphylite...
lithosphere
lithosphere, rigid, rocky outer layer of Earth, consisting of the crust and the solid outermost layer of the upper......
litoptern
litoptern, (order Litopterna), any of various extinct hoofed mammals that first appeared in the Paleocene Epoch......
Little Ice Age
Little Ice Age (LIA), climate interval that occurred from the early 14th century through the mid-19th century,......
Lituites
Lituites, genus of extinct cephalopods (primitive animals related to the modern pearly nautilus) found as fossils......
Lixisol
Lixisol, one of the 30 soil groups in the classification system of the Food and Agriculture Organization (FAO).......
Llanocetus denticrenatus
Llanocetus denticrenatus, one of the earliest known baleen whales, sole member of the family Llanocetidae, suborder......
Lluc
Lluc, (Anoiapithecus brevirostris), nickname for the nearly complete upper and lower jaws and much of the associated......
loam
loam, Rich, friable (crumbly) soil with nearly equal parts of sand and silt, and somewhat less clay. The term is......
loellingite
loellingite, an iron arsenide mineral (FeAs2) that usually occurs with iron and copper sulfides in hydrothermal......
loess
loess, an unstratified, geologically recent deposit of silty or loamy material that is usually buff or yellowish......
Logan, Sir William Edmond
Sir William Edmond Logan was one of the foremost Canadian geologists of the 19th century. Logan was educated at......
Lonsdale, William
William Lonsdale was an English geologist and paleontologist whose studies of fossil corals suggested the existence......
lophophore hypothesis
lophophore hypothesis, viewpoint that conodonts, small toothlike structures found as fossils in marine rocks over......
Lophophyllum
Lophophyllum, extinct genus of solitary marine corals found as fossils especially characteristic of the Late Carboniferous......
Lophospira
Lophospira, genus of extinct gastropods (snails) found as fossils in marine rocks of Ordovician to Devonian age......
lopolith
lopolith, igneous intrusion associated with a structural basin, with contacts that are parallel to the bedding......
Lorelei
Lorelei, large rock on the bank at a narrows of the Rhine River near Sankt Goarshausen, Germany. The rock produces......
Lorenz, Edward
Edward Lorenz was an American meteorologist and discoverer of the underlying mechanism of deterministic chaos,......
Loxonema
Loxonema, genus of extinct gastropods (snails) found as fossils in rocks of Ordovician to Early Carboniferous age......
Lucy
Lucy, nickname for a remarkably complete (40 percent intact) hominin skeleton found by American paleoanthropologist......
Lugeon, Maurice
Maurice Lugeon was a Swiss geologist who provided the first comprehensive interpretation of the Alps as a whole.......
lustre
lustre, in mineralogy, the appearance of a mineral surface in terms of its light-reflective qualities. Lustre depends......
lutite
lutite, any fine-grained sedimentary rock consisting of clay- or silt-sized particles (less than 0.063 mm [0.0025......
Luvisol
Luvisol, one of the 30 soil groups in the classification system of the Food and Agriculture Organization (FAO).......
Lyell, Charles
Charles Lyell was a Scottish geologist largely responsible for the general acceptance of the view that all features......
Lystrosaurus
Lystrosaurus, extinct genus of about seven species of medium-sized heavily built animals that lived from the middle......
L’Aquila earthquake of 2009
L’Aquila earthquake of 2009, severe earthquake that occurred on April 6, 2009, near the city of L’Aquila in the......
Mackinder, Halford
Halford Mackinder was a British political geographer noted for his work as an educator and for his geopolitical......
Maclurites
Maclurites, extinct genus of Ordovician gastropods (snails) found as fossils and useful for stratigraphic correlations......
Madden-Julian oscillation
Madden-Julian oscillation (MJO), intraseasonal fluctuation of atmospheric pressure over the equatorial Indian and......
mafic rock
mafic rock, in geology, igneous rock that is dominated by the silicates pyroxene, amphibole, olivine, and mica.......
Magellan, Ferdinand
Ferdinand Magellan was a Portuguese navigator and explorer who sailed under the flags of both Portugal (1505–13)......
maghemite
maghemite, an iron oxide mineral. It has a composition close to ferric oxide (Fe2O3) and exhibits strong magnetism......
magma
magma, molten or partially molten rock from which igneous rocks form. It usually consists of silicate liquid, although......
magnesite
magnesite, the mineral magnesium carbonate (MgCO3), a member of the calcite group of carbonate minerals that is......
magnetic survey
magnetic survey, one of the tools used by exploration geophysicists in their search for mineral-bearing ore bodies......
Magnetosphere
Magnetosphere, region in the atmosphere where magnetic phenomena and the high atmospheric conductivity caused by......
malachite
malachite, a minor ore but a widespread mineral of copper, basic copper carbonate, Cu2CO3(OH)2. Because of its......
Malte-Brun, Conrad
Conrad Malte-Brun was an author and coauthor of several geographies and a founder of the first modern geographic......
mammoth
mammoth, (genus Mammuthus), any member of an extinct group of elephants found as fossils in Pleistocene deposits......
Manabe Syukuro
Manabe Syukuro is a meteorologist who was awarded the Nobel Prize for Physics in 2021 for the foundational progress......
manganite
manganite, an ore mineral of manganese, basic manganese oxide [MnO(OH)] that forms dark gray to black crystal bundles......
mansfieldite
mansfieldite, arsenate mineral (AlAsO4·2H2O) similar to scorodite...
Mantell, Gideon Algernon
Gideon Algernon Mantell was a British physician, geologist, and paleontologist, who discovered four of the five......
Maqdisī, al-
al-Maqdisī was an Arab traveler, geographer, and author of a noted work based on personal observations of the populations,......
Marasuchus
Marasuchus, genus of archosaurian reptiles that inhabited part of present-day South America during the Ladinian......
marble
marble, granular limestone or dolomite (i.e., rock composed of calcium-magnesium carbonate) that has been recrystallized......
Marbut, Curtis Fletcher
Curtis Fletcher Marbut was an American geologist and authority on soils who worked closely with experts from many......
marcasite
marcasite, an iron sulfide mineral that forms pale bronze-yellow orthorhombic crystals, usually twinned to characteristic......
marine geology
marine geology, scientific discipline that is concerned with all geological aspects of the continental shelves......
marine geophysics
marine geophysics, scientific discipline that is concerned with the application of geophysical methods to problems......
Marine west coast climate
Marine west coast climate, major climate type of the Köppen classification characterized by equable climates with......
Maritime air mass
Maritime air mass, vast body of air of oceanic origin; also, an air mass (q.v.) that has had a long trajectory......
marl
marl, old term used to refer to an earthy mixture of fine-grained minerals. The term was applied to a great variety......
Marsh, George Perkins
George Perkins Marsh was a U.S. diplomat, scholar, and conservationist whose greatest work, Man and Nature (1864),......
Marsh, Othniel Charles
Othniel Charles Marsh was an American paleontologist who made extensive scientific explorations of the western......
massicot
massicot, one of the two forms of lead oxide (PbO) that occurs as a mineral (the other form is litharge). Massicot......
mastodon
mastodon, (genus Mammut), any of several extinct elephantine mammals (family Mammutidae, genus Mammut ) that first......
Masʿūdī, al-
al-Masʿūdī was a historian and traveler, known as the “Herodotus of the Arabs.” He was the first Arab to combine......
matrix
matrix, in geology, the material in which something is embedded, either the natural rock that holds crystals, fossils,......
Matthew, William Diller
William Diller Matthew was a Canadian-American paleontologist who was an important contributor to modern knowledge......
maucherite
maucherite, a nickel arsenide mineral with chemical composition approximating Ni11As8, assigned to the group of......
Mauer
Mauer, Pleistocene locality on the Neckar River of Germany and the name of a Pleistocene deposit, the Mauer Sands......
Maury, Matthew Fontaine
Matthew Fontaine Maury was a U.S. naval officer, pioneer hydrographer, and one of the founders of oceanography.......
McMurdo Station
McMurdo Station, research and logistics installation located on the Hut Point Peninsula, on Ross Island, Antarctica.......
McNutt, Marcia
Marcia McNutt is an American geophysicist who was the first woman to direct the U.S. Geological Survey (USGS; 2009–13)......
Mediterranean climate
Mediterranean climate, major climate type of the Köppen classification characterized by hot, dry summers and cool,......
megalodon
megalodon, (Carcharocles megalodon), member of an extinct species of megatooth shark (Otodontidae) that is considered......
Megatherium
Megatherium, largest of the ground sloths, an extinct group of mammals belonging to a group containing sloths,......
Mela, Pomponius
Pomponius Mela was the author of the only ancient treatise on geography in classical Latin, De situ orbis (“A Description......
melilite
melilite, any member of a series of sorosilicate minerals that consist of calcium silicates of aluminum and magnesium;......
Mendenhall, Thomas Corwin
Thomas Corwin Mendenhall was an American physicist and meteorologist, the first to propose the use of a ring pendulum......
mercury
mercury (Hg), chemical element, liquid metal of Group 12 (IIb, or zinc group) of the periodic table. atomic number80......
meridian
meridian, imaginary north–south line on the Earth’s surface that connects both geographic poles; it is used to......
Merychippus
Merychippus, extinct genus of early horses, found as fossils in deposits from the Middle and Late Miocene Epoch......
Mesohippus
Mesohippus, genus of extinct early and middle Oligocene horses (the Oligocene Epoch occurred from 33.9 to 23 million......
Mesosaurus
Mesosaurus, (genus Mesosaurus), early aquatic relative of reptiles, found as fossils from the Early Permian Period......
Mesosphere
Mesosphere, region of the upper atmosphere between about 50 and 80 km (30 and 50 miles) above the surface of the......
Mesozoic Era
Mesozoic Era, second of Earth’s three major geologic eras of Phanerozoic time. Its name is derived from the Greek......
Messina earthquake and tsunami of 1908
Messina earthquake and tsunami of 1908, earthquake and subsequent tsunami that devastated southern Italy on Dec.......
metacinnabar
metacinnabar, a mercury sulfide mineral that has the same chemical composition as cinnabar (HgS). Typical specimens......
metallography
metallography, study of the structure of metals and alloys, particularly using microscopic (optical and electron)......
metallurgy
metallurgy, art and science of extracting metals from their ores and modifying the metals for use. Metallurgy customarily......
- Introduction
- Copper Alloy, Zinc Alloy, Brass
- Iron, Steel, Alloy
- Aluminum, Magnesium, Titanium
- Extractive, Refining, Alloying
- Roasting, Smelting, Refining
- Matte Smelting, Refining, Alloying
- Refining, Alloying, Smelting
- Leaching, Extraction, Refining
- Alloying, Heat Treatment, Casting
- Electrical Properties
- Alloying, Refining, Smelting
- Casting, Alloying, Refining
- Metalworking, Alloying, Refining
- Forging, Heat Treatment, Alloying
- Powder, Process, Components
- Hardening, Treatments, Heat
- Corrosion Resistance, Alloying, Heat Treatment
- Nitriding, Alloying, Hardening
- Testing, Mechanical Properties
metamorphic rock
metamorphic rock, any of a class of rocks that result from the alteration of preexisting rocks in response to changing......
- Introduction
- Pressure, Temperature, & Deformation
- Pressure, Heat, Transformation
- Heat, Pressure, Reactions
- Isograds, Foliations, Textures
- Retrograde Metamorphism
- Foliated, Textures, Minerals
- Foliations, Textures, Deformations
- Facies, Pressure, Heat
- Pressure, Temperature, Time
- Regional, Foliated, Pressure
- Zeolite Facies, Minerals, Textures
- Foliated, Igneous, Sedimentary
- Foliated, Non-Foliated, Textures
metamorphism
metamorphism, mineralogical and structural adjustments of solid rocks to physical and chemical conditions differing......
metasomatic replacement
metasomatic replacement, the process of simultaneous solution and deposition whereby one mineral replaces another.......
Meteor Crater
Meteor Crater, rimmed, bowl-shaped pit produced by the impact of a large meteorite in the rolling plain of the......
Meteorite crater
Meteorite crater, depression that results from the impact of a natural object from interplanetary space with Earth......
Meteorology
Meteorology, Scientific study of atmospheric phenomena, particularly of the troposphere and lower stratosphere.......
Methane burp hypothesis
Methane burp hypothesis, in oceanography and climatology, an explanation of the sudden onset of the Paleocene-Eocene......