Term
|
Definition
| The disk-shaped body of gas, ice, and dust onto which matter falls; it ultimately evolves into a solar system. (page 18) |
|
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Term
|
Definition
| One of the fragments of solid material, left over from planet formation or produced by collision of planetesimals, that resides between the orbits of Mars and Jupiter. (page 14) |
|
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Term
|
Definition
| The layer of the mantle that lies between 100 - 150 km and 350 km deep that is relatively soft and can flow when acted on by force. (page 38) |
|
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Term
|
Definition
| A layer of gases that surrounds a planet. (page 28) |
|
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Term
|
Definition
Variation in depth of water in oceans, seas, or lakes.
(page 30) |
|
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Term
|
Definition
| A cataclysmic explosion that scientists suggest represents the formation of the Universe; before this event, all matter and all energy were packed into one volumeless point. (page 16) |
|
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Term
|
Definition
| The region of the Earth and atmosphere inhabited by life; this region stretches from a few km below the Earth's surface to a few km above. (page 31) |
|
|
Term
|
Definition
| A ball of ice and dust, probably remaining from the formation of the Solar System, that orbits the Sun. (page 14) |
|
|
Term
|
Definition
| The study of the overall structure of the Universe. (page 11) |
|
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Term
|
Definition
| The rock that makes up the outermost layer of the Earth. (page 36) |
|
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Term
|
Definition
| The ice components of the Earth System, including glaciers, snow, sea ice, and permafrost. (page 29) |
|
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Term
|
Definition
| A single, continuous piece of a mineral bounded by flat surfaces that formed naturally as the mineral grew. (page 30) |
|
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Term
|
Definition
| A process early in a planet's history during which dense iron alloy melted and sank downward to form the core, leaving less-dense mantle behind. (page 23) |
|
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Term
|
Definition
| A magnetic field with a north and south pole, like that of a bar magnet. (page 26) |
|
|
Term
|
Definition
| A vibration caused by the sudden breaking or frictional sliding of rock in the Earth. (page 34) |
|
|
Term
|
Definition
| Any of the substances (minerals, rocks, metals, sediments, soils) composing the solid Earth. (page 30) |
|
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Term
|
Definition
| The global interconnecting web of physical and biological phenomena involving the solid Earth, the hydrosphere, and the atmosphere. (page 28) |
|
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Term
|
Definition
| The plane defined by a planet's orbit. (page 13) |
|
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Term
|
Definition
| The grinding away and removal of Earth's surface materials by moving water, air, or ice. (page 33) |
|
|
Term
| Expanding Universe theory |
|
Definition
| The theory that the whole Universe must be expanding because galaxies in every direction seem to be moving away from us. (page 15) |
|
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Term
|
Definition
| Energy from the Sun that drives components of the Earth System; it contributes to the circulation and flow of the atmosphere and hydrosphere, and serves a major role in driving erosion. (page 33) |
|
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Term
|
Definition
| An immense system of hundreds of billions of stars. (page 13) |
|
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Term
|
Definition
| The first model of the universe in which the Earth sits motionless at the center of the Universe while the Moon and the planets whirl around it, and everything lies inside a revolving globe of stars. (page 12) |
|
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Term
|
Definition
| The solid Earth, from the surface to the center. (page 29) |
|
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Term
|
Definition
| The rate of change in temperature with depth. (page 36) |
|
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Term
|
Definition
| The four outer, or Jovian, planets of our Solar System, which are significantly larger than the rest of the planets and consist largely of gas and/or ice. (page 13) |
|
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Term
|
Definition
| Water that resides under the surface of the Earth, mostly in pores or cracks of rock or sediment. (page 29) |
|
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Term
|
Definition
| Thermal energy resulting from the movement of molecules. (page 20) |
|
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Term
|
Definition
| An idea proposed by Greek philosophers around 250 B.C.E. suggesting that all heavenly objects including the Earth orbited the Sun. (page 12) |
|
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Term
|
Definition
| The Earth's water, including surface water (lakes, rivers, and oceans), groundwater, and liquid water in the atmosphere. (page 29) |
|
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Term
|
Definition
| Energy that comes from the Earth's internal heat; it drives plate tectonics, and therefore, earthquakes, volcanoes, and mountain building. (page 32) |
|
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Term
|
Definition
| The relatively rigid, nonflowable, outer 100- to 150-km-thick layer of the Earth, constituting the crust and the top part of the mantle. (page 38) |
|
|
Term
|
Definition
| The region affected by the force emanating from a magnet. (page 26) |
|
|
Term
|
Definition
| The region protected from the electrically charged particles of the solar winds by Earth's magnetic field. (page 26) |
|
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Term
|
Definition
| Molten (liquid) rock. (page 31) |
|
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Term
|
Definition
| A solid composed almost entirely of atoms of metallic elements; it is generally opaque, shiny, smooth, malleable, and can conduct electricity. (page 31) |
|
|
Term
|
Definition
| A streak of bright, glowing gas created as a meteoroid vaporizes in the atmosphere due to friction. (page 35) |
|
|
Term
|
Definition
| A piece of rock or metal alloy that fell from space and landed on Earth. (page 35) |
|
|
Term
|
Definition
| A homogenous, naturally occurring, solid inorganic substance with a definable chemical composition and an internal structure characterized by an orderly arrangement of atoms, ions, or molecules in a lattice. Most are inorganic. (page 30) |
|
|
Term
|
Definition
| The seismic-velocity discontinuity that defines the boundary between the Earth's crust and mantle. Named for Andrija Mohorovi. (page 36) |
|
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Term
|
Definition
| A sizable solid body locked in orbit around a planet. (page 14) |
|
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Term
|
Definition
| A cloud of gas or dust in space. (page 18) |
|
|
Term
|
Definition
| The concept that planets grow out of rings of gas, dust, and ice surrounding a newborn star. (page 18) |
|
|
Term
|
Definition
| A radioactive element whose nuclei spontaneously emits subatomic particles, or undergoes nuclear fission by breaking into two smaller nuclei. (page 23) |
|
|
Term
|
Definition
| The process by which the nuclei of atoms fuse together, thereby creating new, larger atoms. (page 18) |
|
|
Term
|
Definition
| An object that orbits a star, is roughly spherical, and has cleared its neighborhood of other objects. (page 13) |
|
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Term
|
Definition
| Tiny, solid pieces of rock and metal that collect in a planetary nebula and eventually accumulate to form a planet. (page 22) |
|
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Term
|
Definition
| A body that grows by the accumulation of planetesimals but has not yet become big enough to be called a planet. (page 22) |
|
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Term
|
Definition
| A dense body of gas that is collapsing inward because of gravitational forces and that may eventually become a star. (page 18) |
|
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Term
|
Definition
| Substances that have a relatively high melting point and tend to exist in solid form. (page 22) |
|
|
Term
|
Definition
| A coherent, naturally occurring solid, consisting of an aggregate of minerals or a mass of glass. (page 30) |
|
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Term
|
Definition
| Rock composed of silicate minerals. (page 31) |
|
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Term
|
Definition
| Our Sun and all the materials that orbit it (including planets, moons, asteroids, Kuiper Belt objects, and Oort Cloud objects). (page 13) |
|
|
Term
|
Definition
| An object in the Universe in which fusion reactions occur pervasively, producing vast amounts of energy; our Sun is an example. (page 12) |
|
|
Term
|
Definition
| The production of new, larger atoms by fusion reactions in stars; the process generates more massive elements that were not produced by the Big Bang. (page 19) |
|
|
Term
|
Definition
| The stream of atoms emitted from a star into space. (page 19) |
|
|
Term
|
Definition
| A short-lived, very bright object in space that results from the cataclysmic explosion marking the death of a very large star; the explosion ejects large quantities of matter into space to form new nebulae. (page 19) |
|
|
Term
|
Definition
| A measure of the hotness or coldness of a material. (page 20) |
|
|
Term
|
Definition
| Planets that are of comparable size and character to the Earth and consist of a metallic core surrounded by a rock mantle. (page 13) |
|
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Term
|
Definition
| Variations in land surface elevation. (page 30) |
|
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Term
|
Definition
| All of space and all the matter and energy within it. (page 12) |
|
|
Term
|
Definition
| Space that contains very little matter in a given volume (e.g., a region in which air has been removed). (page 18) |
|
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Term
|
Definition
| Elements or compounds such as H2O and CO2 that evaporate at relatively low temperatures and can exist in gaseous forms at the Earth's surface. (pages 21, 31) |
|
|
Term
|
Definition
| The movement of a plate relative to a fixed point in the mantle. (page 77) |
|
|
Term
|
Definition
| A wedge-shaped mass of sediment and rock scraped off the top of a downgoing plate and accreted onto the overriding plate at a convergent plate margin. (page 66) |
|
|
Term
|
Definition
| Plate boundaries. (page 61) |
|
|
Term
| Apparent polar-wander path |
|
Definition
| A path on the globe along which a magnetic pole appears to have wandered over time; in fact, the continents drift, while the magnetic pole stays fairly fixed. (page 50) |
|
|
Term
|
Definition
| The layer of the mantle that lies between 100 - 150 km and 350 km deep that is relatively soft and can flow when acted on by force. (page 38) |
|
|
Term
|
Definition
| The cloud of suspended minerals formed where hot water spews out of a vent along a mid-ocean ridge; the dissolved sulfide components of the hot water instantly precipitate when the water mixes with seawater and cools. (page 63) |
|
|
Term
|
Definition
| The process of two buoyant pieces of lithosphere converging and squashing together. (page 72) |
|
|
Term
|
Definition
| The process by which a continent stretches and splits along a belt; if it is successful, this separates a larger continent into two smaller continents. (page 72) |
|
|
Term
|
Definition
| A boundary at which two plates move toward each other so that one plate sinks (subducts) beneath the other; only oceanic lithosphere can subduct. (page 61) |
|
|
Term
|
Definition
| A boundary at which two lithosphere plates move apart from each other; they are marked by mid-ocean ridges. (page 61) |
|
|
Term
|
Definition
| A narrow band of vertical fractures in the ocean floor; these zones lie roughly at right angles to a mid-ocean ridge. The actively slipping part of the zone is a transform fault. (page 53), 67 |
|
|
Term
|
Definition
| A location at the base of the lithosphere, at the top of a mantle plume, where temperatures can cause melting. (page 70) |
|
|
Term
|
Definition
| A chain of now-dead volcanoes transported off the hot spot by the movement of a lithosphere plate. (page 70) |
|
|
Term
|
Definition
| The relatively rigid, nonflowable, outer 100- to 150-km-thick layer of the Earth, constituting the crust and the top part of the mantle. (page 59) |
|
|
Term
|
Definition
| The difference between the expected strength of the Earth's magnetic field at a certain location and the actual measured strength of the field at that location. (page 55) |
|
|
Term
|
Definition
| The angle between the direction a compass needle points at a given location and the direction of true north. (page 48) |
|
|
Term
|
Definition
| The angle between a magnetic needle free to pivot on a horizontal axis and a horizontal plane parallel to the Earth's surface. (page 48) |
|
|
Term
|
Definition
| The change of the Earth's magnetic polarity; when a reversal occurs, the field flips from normal to reversed polarity, or vice versa. (page 57) |
|
|
Term
| Magnetic-reversal chronology |
|
Definition
| The history of magnetic reversals through geologic time. (page 57) |
|
|
Term
|
Definition
| A column of very hot rock rising up through the mantle. (page 70) |
|
|
Term
|
Definition
| The difference between the expected strength of the Earth's main dipole field at a certain location on the sea floor and the actual measured strength of the magnetic field at that location. (page 55) |
|
|
Term
|
Definition
| A 2-km-high submarine mountain belt that forms along a divergent oceanic plate boundary. (page 51) |
|
|
Term
|
Definition
| The record of ancient magnetism preserved in rock. (page 49) |
|
|
Term
|
Definition
| The supposed position of the Earth's magnetic pole in the past, with respect to a particular continent. (page 50) |
|
|
Term
|
Definition
| A continental margin that is not a plate boundary. (page 61) |
|
|
Term
|
Definition
| One of about 20 distinct pieces of the relatively rigid lithosphere. (page 44) |
|
|
Term
|
Definition
| The border between two adjacent lithosphere plates. (page 61) |
|
|
Term
|
Definition
| The theory that the outer layer of the Earth (the lithosphere) consists of separate plates that move with respect to one another. (page 44) |
|
|
Term
|
Definition
| The movement of one lithosphere plate with respect to another. (page 75) |
|
|
Term
|
Definition
| A linear belt along which continental lithosphere stretches and pulls apart. (page 72) |
|
|
Term
|
Definition
| The gradual widening of an ocean basin as new oceanic crust forms at a mid-ocean ridge axis and then moves away from the axis. (page 54) |
|
|
Term
|
Definition
| An isolated submarine mountain. (page 53) |
|
|
Term
|
Definition
| The force that downgoing plates (or slabs) apply to oceanic lithosphere at a convergent margin. (page 75) |
|
|
Term
|
Definition
| The process by which one oceanic plate bends and sinks down into the asthenosphere beneath another plate. (page 65) |
|
|
Term
|
Definition
| A boundary at which one lithosphere plate slips laterally past another. (page 61) |
|
|
Term
|
Definition
A deep, elongate trough bordering a volcanic arc that defines the trace of a convergent plate boundary.
(page 53) |
|
|
Term
|
Definition
| A point where three lithosphere plate boundaries intersect. (page 59) |
|
|
Term
|
Definition
| A curving chain of active volcanoes formed adjacent to a convergent plate boundary. (page 53) |
|
|
Term
|
Definition
| A sloping band of seismicity defined by intermediate- and deep-focus earthquakes that occur in the downgoing slab of a convergent plate boundary. (page 65) |
|
|
Term
|
Definition
| The characteristic of a material due to the spectrum of light emitted or reflected by the material, as perceived by eyes or instruments. (page 91) |
|
|
Term
|
Definition
| A single, continuous piece of a mineral bounded by flat surfaces that formed naturally as the mineral grew. (page 85) |
|
|
Term
|
Definition
| The flat surfaces of a crystal, formed during the crystal's growth. (page 85) |
|
|
Term
|
Definition
| The general shape of a crystal or cluster of crystals that grew unimpeded. (page 93) |
|
|
Term
|
Definition
| The orderly framework within which the atoms or ions of a mineral are fixed. (page 84) |
|
|
Term
|
Definition
| Containing a crystal lattice. (page 84) |
|
|
Term
|
Definition
| The ground and polished surface of a gem, produced by a gem cutter using a grinding lap. (page 99) |
|
|
Term
|
Definition
| A finished (cut and polished) gemstone ready to be set in jewelry. (page 97) |
|
|
Term
|
Definition
| A mineral that has special value because it is rare and people consider it beautiful. (page 97) |
|
|
Term
|
Definition
| A solid in which atoms are not arranged in an orderly pattern. (page 84) |
|
|
Term
|
Definition
| A measure of the relative ability of a mineral to resist scratching; it represents the resistance of bonds in the crystal structure from being broken. (page 91) |
|
|
Term
|
Definition
| The way a mineral surface scatters light. (page 91) |
|
|
Term
|
Definition
| A homogenous, naturally occurring, solid inorganic substance with a definable chemical composition and an internal structure characterized by an orderly arrangement of atoms, ions, or molecules in a lattice. Most minerals are inorganic. (page 84) |
|
|
Term
|
Definition
| Distinguishing minerals from each other on the basis of chemical composition. (page 95) |
|
|
Term
|
Definition
| A list of ten minerals in a sequence of relative hardness, with which other minerals can be compared. (page 91) |
|
|
Term
|
Definition
| Two minerals that have the same chemical composition but a different crystal lattice structure. (page 88) |
|
|
Term
|
Definition
| Minerals built from silicon-oxygen tetrahedra arranged in chains, sheets, or 3-D networks; they make up most of the Earth's crust and mantle. (page 95) |
|
|
Term
| Silicon-oxygen tetrahedron |
|
Definition
| The SiO44 - anionic group, in which four oxygen atoms surround a single silicon atom, thereby defining the corners of a tetrahedron. (page 95) |
|
|
Term
|
Definition
| A number representing the density of a mineral, as specified by the ratio between the weight of a volume of the mineral and the weight of an equal volume of water. (page 92) |
|
|
Term
|
Definition
| The color of the powder produced by pulverizing a mineral on an unglazed ceramic plate. (page 91) |
|
|
Term
|
Definition
| The process of magma contamination in which blocks of wall rock fall into a magma chamber and dissolve. (page 118) |
|
|
Term
|
Definition
| A vast composite, intrusive, igneous rock body up to several hundred km long and 100 km wide, formed by the intrusion of numerous plutons in the same region. (page 121) |
|
|
Term
|
Definition
| The sequence in which different silicate minerals crystallize during the progressive cooling of a melt. (page 122) |
|
|
Term
|
Definition
| A rock that consists of minerals that grew when a melt solidified, and eventually interlock like pieces of a jigsaw puzzle. (page 127) |
|
|
Term
|
Definition
| A tabular (wall-shaped) intrusion of rock that cuts across the layering of country rock. (page 121) |
|
|
Term
|
Definition
| Rock that forms by the freezing of lava above ground, after it flows or explodes out (extrudes) onto the surface and comes into contact with the atmosphere or ocean. (page 115) |
|
|
Term
|
Definition
| Vast sheets of basalt that spread from a volcanic vent over an extensive surface of land; they may form where a rift develops above a continental hot spot, and where lava is particularly hot and has low viscosity. (page 133) |
|
|
Term
| Fractional crystallization |
|
Definition
| The process by which a magma becomes progressively more silicic as it cools, because early-formed crystals settle out. (page 120) |
|
|
Term
|
Definition
| A rock consisting of igneous chunks and/or shards that are packed together, welded together, or cemented together after having solidified. (page 127) |
|
|
Term
|
Definition
| Igneous rock consisting entirely of glass, or of tiny crystals surrounded by a glass matrix. (page 127) |
|
|
Term
|
Definition
| Rock that forms when hot molten rock (magma or lava) cools and freezes solid. (page 114) |
|
|
Term
|
Definition
| Rock formed by the freezing of magma underground. (page 115) |
|
|
Term
|
Definition
| A blister-shaped igneous intrusion that forms when magma injects between layers underground in a manner that pushes overlying layers upward to form a dome. (page 121) |
|
|
Term
| Large igneous province (LIP) |
|
Definition
| A region in which huge volumes of lava and/or ash erupted over a relatively short interval of geologic time. (page 133) |
|
|
Term
|
Definition
| Molten rock that has flowed out onto the Earth's surface. (page 113) |
|
|
Term
|
Definition
| Molten rock beneath the Earth's surface. (page 115) |
|
|
Term
|
Definition
| A space below ground filled with magma. (page 125) |
|
|
Term
|
Definition
| An igneous rock consisting of a solid mass of volcanic glass. (page 129) |
|
|
Term
|
Definition
| The melting in a rock of the minerals with the lowest melting temperatures, while other minerals remain solid. (page 118) |
|
|
Term
|
Definition
| An irregular or blob-shaped intrusion; can range in size from tens of m across to tens of km across. (page 121) |
|
|
Term
|
Definition
| A glassy igneous rock that forms from felsic frothy lava and contains abundant (over 50%) pore space. (page 129) |
|
|
Term
|
Definition
| Fragmented material that sprayed out of a volcano and landed on the ground or sea floor in solid form. (page 115) |
|
|
Term
|
Definition
| Rock made from fragments that were blown out of a volcano during an explosion and were then packed or welded together. (page 129) |
|
|
Term
|
Definition
| A glassy, mafic, igneous rock containing abundant air-filled holes. (page 129) |
|
|
Term
|
Definition
| A nearly horizontal tabletop-shaped tabular intrusion that occurs between the layers of country rock. (page 121) |
|
|
Term
|
Definition
| A basaltic volcanic glass. (page 129) |
|
|
Term
|
Definition
| A pyroclastic igneous rock composed of volcanic ash and fragmented pumice, formed when accumulations of the debris cement together. (page 129) |
|
|
Term
|
Definition
| Open holes in igneous rock formed by the preservation of bubbles in magma as the magma cools into solid rock. (page 129) |
|
|
Term
|
Definition
| The resistance of material to flow. (page 119) |
|
|
Term
|
Definition
| A curving chain of active volcanoes formed adjacent to a convergent plate boundary. (page 130) |
|
|
Term
|
Definition
| Tiny glass shards formed when a fine spray of exploded lava freezes instantly upon contact with the atmosphere. (page 115) |
|
|
Term
|
Definition
| (1) A vent from which melt from inside the Earth spews out onto the planet's surface; (2) a mountain formed by the accumulation of extrusive volcanic rock. (page 113) |
|
|
Term
| Xenolith (Xeno from Greek word for foreign) |
|
Definition
| A body of rock within intusive igneious rock that did not crystalize from the same magma (page 125) |
|
|
Term
|
Definition
| A lava flow with a rubbly surface. (page 138) |
|
|
Term
|
Definition
| A volcano that has erupted within the past few centuries and will likely erupt again. (page 161) |
|
|
Term
|
Definition
| Tiny solid particles or liquid droplets that remain suspended in the atmosphere for a long time. (page 144) |
|
|
Term
|
Definition
| Tiny glass shards formed when a fine spray of exploded lava freezes instantly upon contact with the atmosphere. (page 142) |
|
|
Term
|
Definition
| Large, angular pyroclastic fragments consisting of volcanic rock, broken up during the eruption. (page 142) |
|
|
Term
|
Definition
| Lava that is so viscous that it breaks into boulder-like blocks as it moves; typically, such lavas are andesitic or rhyolitic. (page 139) |
|
|
Term
|
Definition
| Larger blobs of lava that squirt out of a vent and then solidify whose surfaces are typically streaked and polished. (page 142) |
|
|
Term
|
Definition
| A large circular depression with steep walls and a fairly flat floor, formed after an eruption as the center of the volcano collapses into the drained magma chamber below. (page 145) |
|
|
Term
|
Definition
| A subaerial volcano consisting of a cone-shaped pile of tephra whose slope approaches the angle of repose for tephra. (page 145) |
|
|
Term
|
Definition
| A type of fracturing that yields roughly hexagonal columns of basalt that form when a dike, sill, or lava flow contracts during cooling. (page 139) |
|
|
Term
|
Definition
| (1) A circular depression at the top of a volcanic mound; (2) a depression formed by the impact of a meteorite. (page 145) |
|
|
Term
|
Definition
| A volcano that has not erupted for hundreds to thousands of years but does have the potential to erupt again in the future. (page 161) |
|
|
Term
|
Definition
| An eruption that yields mostly lava, not ash. (page 146) |
|
|
Term
|
Definition
| Episodes when volcanoes extrude lava and pyroclastic debris. (page 137) |
|
|
Term
|
Definition
| The character of a particular volcanic eruption; geologists name styles based on typical examples (e.g., Hawaiian, Strombolian). (page 145) |
|
|
Term
|
Definition
| Violent volcanic eruptions that produce clouds and avalanches of pyroclastic debris. (page 146) |
|
|
Term
|
Definition
| A volcano that was active in the past but has now shut off entirely and will not erupt in the future. (page 161) |
|
|
Term
|
Definition
| A conduit in a magma chamber in the shape of a long crack through which magma rises and erupts at the surface. (page 145) |
|
|
Term
|
Definition
| Vast sheets of basalt that spread from a volcanic vent over an extensive surface of land; they may form where a rift develops above a continental hot spot, and where lava is particularly hot and has low viscosity. (page 156) |
|
|
Term
|
Definition
| A thick slurry formed when volcanic ash and debris mix with water, either in rivers or from rain or melting snow and ice on the flank of a volcano. (page 144) |
|
|
Term
|
Definition
| Any pyroclastic particle that is 2 to 64 mm in diameter (i.e., marble-sized); the particles can consist of frozen lava clots, pumice fragments, or ash clumps. (page 142) |
|
|
Term
| Large igneous province (LIP) |
|
Definition
| A region in which huge volumes of lava and/or ash erupted over a relatively short interval of geologic time. (page 156) |
|
|
Term
|
Definition
| A dome-like mass of rhyolitic lava that accumulates above the eruption vent. (page 139) |
|
|
Term
|
Definition
| Sheets or mounds of lava that flow onto the ground surface or sea floor in molten form and then solidify. (page 138) |
|
|
Term
|
Definition
| A column of molten lava spraying upward under pressure from a volcanic vent. (page 142) |
|
|
Term
|
Definition
| The empty space left when a lava tunnel drains; this happens when the surface of a lava flow solidifies while the inner part of the flow continues to stream downslope. (page 138) |
|
|
Term
|
Definition
| A space below ground filled with magma. (page 145) |
|
|
Term
|
Definition
| A lava flow with a surface texture of smooth, glassy, ropelike ridges. (page 138) |
|
|
Term
|
Definition
| The rind of a pillow momentarily stops the flow's advance, but within minutes the pressure of the lava squeezing into the pillow breaks the rind, and a new blob of lava squirts out, freezes, and produces another pillow. (page 139) |
|
|
Term
|
Definition
| Fragmented material that sprayed out of a volcano and landed on the ground or sea floor in solid form. (page 141) |
|
|
Term
|
Definition
| A fast-moving avalanche that occurs when hot volcanic ash and debris mix with air and flow down the side of a volcano. (page 142) |
|
|
Term
|
Definition
| A subaerial volcano with a broad, gentle dome, formed either from low-viscosity basaltic lava or from large pyroclastic sheets. (page 145) |
|
|
Term
|
Definition
| Rhyolitic lava freezes while still in the vent and then pushes upward as a column-like spire up to 100 m above the vent. (page 139) |
|
|
Term
|
Definition
| A large, cone-shaped subaerial volcano consisting of alternating layers of lava and tephra. (page 145) |
|
|
Term
|
Definition
| A volcano that erupts a vast amount (more than 1,000 cubic km) of volcanic material during a single event; none have erupted during recorded human history. (page 148) |
|
|
Term
|
Definition
| Unconsolidated accumulations of pyroclastic grains ejected by a volcanic eruption. (page 141) |
|
|
Term
|
Definition
| A pyroclastic igneous rock composed of volcanic ash and fragmented pumice, formed when accumulations of the debris cement together. (page 142) |
|
|
Term
|
Definition
| Open holes in igneous rock formed by the preservation of bubbles in magma as the magma cools into solid rock. (page 144) |
|
|
Term
|
Definition
| The resistance of material to flow. (page 138) |
|
|
Term
|
Definition
| A mixture of water and pyroclastic debris that moves downslope like wet concrete. (page 144) |
|
|
Term
|
Definition
| (1) A vent from which melt from inside the Earth spews out onto the planet's surface; (2) a mountain formed by the accumulation of extrusive volcanic rock. (page 137) |
|
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Term
|
Definition
| The process in which chemical reactions alter or destroy minerals when rock comes in contact with water solutions and/or air. (page 174) |
|
|
Term
|
Definition
| A fragment or grain produced by the physical or chemical weathering of a pre-existing rock. (page 172) |
|
|
Term
|
Definition
| The grinding away and removal of Earth's surface materials by moving water, air, or ice. (page 173) |
|
|
Term
|
Definition
| The process in which intact rock breaks into smaller grains or chunks. (page 172) |
|
|
Term
|
Definition
| An accumulation of loose mineral grains, such as boulders, pebbles, sand, silt, or mud, that are not cemented together. (page 171) |
|
|
Term
|
Definition
| Sediment that has undergone changes at the surface of the Earth, including reaction with rainwater and the addition of organic material. (page 178) |
|
|
Term
|
Definition
| The removal of soil by wind and runoff. (page 183) |
|
|
Term
|
Definition
| Distinct zones within a soil, distinguished from each other by factors such as chemical composition and organic content. (page 180) |
|
|
Term
|
Definition
| In the United States, soil scientists use the U.S. Comprehensive Soil Classification System to determine this based upon the physical characteristics and environment of soil formation. (page 181) |
|
|
Term
|
Definition
| A vertical sequence of distinct zones of soil. (page 180) |
|
|
Term
|
Definition
| Ions and clay accumulated in the B-horizon. (page 180) |
|
|
Term
|
Definition
| The top soil horizons, which are typically dark and nutrient-rich. (page 180) |
|
|
Term
|
Definition
| The processes that break up and corrode solid rock, eventually transforming it into sediment. (page 172) |
|
|
Term
|
Definition
| (1) The layer of regolith in which new minerals precipitate out of water passing through, thus leaving behind a load of fine clay; (2) the area of a glacier in which snowfall adds to the glacier. (page 179) |
|
|
Term
|
Definition
| The layer of regolith in which water dissolves ions and picks up very fine clay; these materials are then carried downward by infiltrating water. (page 179) |
|
|
Term
|
Definition
| A gently sloping apron of sediment dropped by an ephemeral stream at the base of a mountain in arid or semiarid regions. (page 203) |
|
|
Term
|
Definition
| A clastic sedimentary rock containing both quartz and feldspar grains. (page 191) |
|
|
Term
|
Definition
| A distinct layer of sediment or sedimentary rock, typically reflecting continuous deposition during a relatively short time interval. (page 197) |
|
|
Term
| Biochemical sedimentary rock |
|
Definition
| Sedimentary rock formed from material (such as shells) produced by living organisms. (page 188) |
|
|
Term
|
Definition
| Coarse sedimentary rock consisting of angular fragments; or rock broken into angular fragments by faulting. (page 191) |
|
|
Term
|
Definition
| The phase of lithification in which minerals that precipitate from groundwater partially or completely fills the spaces between clasts and attaches each grain to its neighbor. (page 189) |
|
|
Term
| Chemical sedimentary rock |
|
Definition
| Sedimentary rocks made up of minerals that precipitate directly from water solution. (page 188) |
|
|
Term
|
Definition
| Sedimentary rock consisting of cemented-together detritus derived from the weathering of preexisting rock. (page 188) |
|
|
Term
|
Definition
| A black, organic rock consisting of greater than 50% carbon; it forms from the buried and altered remains of plant material. (page 199) |
|
|
Term
|
Definition
| The phase of lithification in which the pressure of the overburden on the buried rock squeezes out water and air that was trapped between clasts, and the clasts press tightly together. (page 189) |
|
|
Term
|
Definition
| Very coarse-grained sedimentary rock consisting of rounded clasts. (page 191) |
|
|
Term
|
Definition
| Internal laminations in a bed, inclined at an angle to the main bedding; a relict of the slip face of dunes or ripples. (page 199) |
|
|
Term
|
Definition
| A wedge of sediment formed at a river mouth when the running water of the stream enters standing water, the current slows, the stream loses competence, and sediment settles out. (page 204) |
|
|
Term
|
Definition
| The process by which sediment settles out of a transporting medium. (page 189) |
|
|
Term
|
Definition
| A setting in which sediments accumulate; its character (fluvial, deltaic, reef, glacial, etc.) reflects local conditions. (page 201) |
|
|
Term
|
Definition
| All of the physical, chemical, and biological processes that transform sediment into sedimentary rock and that alter the rock after the rock has formed. (page 210) |
|
|
Term
|
Definition
| A name sometimes used for a carbonate rock containing a high proportion of dolomite. (page 195) |
|
|
Term
|
Definition
| A pile of sand generally formed by deposition from the wind. (page 189) |
|
|
Term
|
Definition
| The grinding away and removal of Earth's surface materials by moving water, air, or ice. (page 194) |
|
|
Term
|
Definition
| Thick salt deposits that form as a consequence of precipitation from saline water. (page 191) |
|
|
Term
|
Definition
| The remnant, or trace, of an ancient living organism that has been preserved in rock or sediment. (page 200) |
|
|
Term
|
Definition
| A layer of sediment, deposited by a turbidity current, in which grain size varies from coarse at the bottom to fine at the top. (page 200) |
|
|
Term
|
Definition
| The transformation of loose sediment into solid rock through compaction and cementation. (page 189) |
|
|
Term
|
Definition
| Very fine-grained sedimentary rock that will not easily split into sheets. (page 191) |
|
|
Term
|
Definition
| Shale containing kerogen. (page 193) |
|
|
Term
|
Definition
| Sedimentary rock (such as coal) formed from carbon-rich relicts of organisms. (page 188) |
|
|
Term
|
Definition
| The seaward migration of a shoreline caused by a lowering of sea level. (page 210) |
|
|
Term
|
Definition
| Relatively small elongated ridges that form on a sedimentary bed surface at right angles to the direction of current flow. (page 199) |
|
|
Term
|
Definition
| Coarse-grained sedimentary rock consisting almost entirely of quartz. (page 189) |
|
|
Term
|
Definition
| A depression, created as a consequence of subsidence, that fills with sediment. (page 209) |
|
|
Term
|
Definition
| Rock that forms either by the cementing together of fragments broken off preexisting rock or by the precipitation of mineral crystals out of water solutions at or near the Earth's surface. (page 188) |
|
|
Term
|
Definition
| A distinctive shape or form (examples -- bed, ripple mark, cross bed) formed during deposition of sediment. (page 196) |
|
|
Term
|
Definition
| Very fine-grained sedimentary rock that breaks into thin sheets. (page 191) |
|
|
Term
|
Definition
| Fine-grained sedimentary rock generally composed of very small quartz grains. (page 191) |
|
|
Term
|
Definition
| (1) The range of clast sizes in a collection of sediment; (2) the degree to which sediment has been separated by flowing currents into different-sized fractions. (page 190) |
|
|
Term
|
Definition
| A succession of several layers or beds together. (page 197) |
|
|
Term
|
Definition
| The vertical sinking of the Earth's surface in a region, relative to a reference plane. (page 209) |
|
|
Term
|
Definition
| The inland migration of shoreline resulting from a rise in sea level. (page 210) |
|
|
Term
|
Definition
| A rock composed of crystalline calcium carbonate (CaCO3) formed by chemical precipitation from ground waterthat has seeped out at the ground surface. (page 194) |
|
|
Term
|
Definition
| A submarine avalanche of sediment and water that speeds down a submarine slope. (page 200) |
|
|
Term
|
Definition
| A graded bed of sediment built up at the base of a submarine slope and deposited by turbidity currents. (page 200) |
|
|
Term
|
Definition
| Metamorphism due only to the consequences of very deep burial. (page 227) |
|
|
Term
|
Definition
| Metamorphism caused by heat conducted into country rock from an igneous intrusion. (page 227) |
|
|
Term
|
Definition
| Metamorphism that occurs as a consequence of shearing alone, with no change in temperature or pressure. (page 227) |
|
|
Term
| Dynamothermal metamorphism |
|
Definition
| Metamorphism that involves heat, pressure, and shearing. (page 230) |
|
|
Term
|
Definition
| The process (involving uplift and erosion) that returns deeply buried rocks to the surface. (page 232) |
|
|
Term
|
Definition
| Layering formed as a consequence of the alignment of mineral grains, or of compositional banding in a metamorphic rock. (page 220) |
|
|
Term
|
Definition
| A compositionally banded metamorphic rock typically composed of alternating dark- and light-colored layers. (page 221) |
|
|
Term
|
Definition
| A dark, fine-grained rock created by metamorphism by a change in temperature, without being subjected to differential stress. (page 223) |
|
|
Term
| Hydrothermal metamorphism |
|
Definition
| When very hot water passes through the crust and causes metamorphism of rock. (page 231) |
|
|
Term
|
Definition
| A metamorphic rock composed of calcite and transformed from a protolith of limestone. (page 223) |
|
|
Term
|
Definition
| A metamorphic rock produced by metamorphism of a conglomerate; typically, it contains flattened pebbles and cobbles. (page 221) |
|
|
Term
|
Definition
| The region around a pluton, stretching tens to hundreds of meters out, in which heat transferred into the country rock and metamorphosed the country rock. (page 227) |
|
|
Term
|
Definition
| A set of metamorphic mineral assemblages indicative of metamorphism under a specific range of pressures and temperatures. (page 226) |
|
|
Term
|
Definition
| A fabric defined by parallel surfaces or layers that develop in a rock as a result of metamorphism; schistocity and gneissic layering are examples. (page 216) |
|
|
Term
|
Definition
| A representation of the intensity of metamorphism, meaning the amount or degree of metamorphic change. (page 223) |
|
|
Term
|
Definition
| New minerals that grow in place within a solid rock under metamorphic temperatures and pressures. (page 216) |
|
|
Term
|
Definition
| Rock that forms when preexisting rock changes into new rock as a result of an increase in pressure and temperature and/or shearing. (page 215) |
|
|
Term
|
Definition
| The region between two metamorphic isograds, typically named after an index mineral found within the region. (page 224) |
|
|
Term
|
Definition
| The process by which one kind of rock transforms into a different kind of rock. (page 215) |
|
|
Term
|
Definition
| The process by which a rock's overall chemical composition changes during metamorphism because of reactions with hot water that bring in or remove elements. (page 219) |
|
|
Term
|
Definition
| A rock formed when gneiss is heated high enough so that it begins to partially melt, creating layers, or lenses, of new igneous rock that mix with layers of the relict gneiss. (page 223) |
|
|
Term
|
Definition
| A fine-grained metamorphic rock with a foliation caused by the preferred orientation of very fine-grained mica. (page 221) |
|
|
Term
|
Definition
| The metamorphic texture that exists where platy grains lie parallel to one another and/or elongate grains align in the same direction. (page 218) |
|
|
Term
|
Definition
| The original rock from which a specific metamorphic rock is formed. (page 215) |
|
|
Term
|
Definition
| A metamorphic rock composed of quartz and transformed from a protolith of quartz sandstone. (page 223) |
|
|
Term
|
Definition
| Metamorphism of a broad region, usually the result of deep burial during an orogeny. (page 230) |
|
|
Term
|
Definition
| A medium-to-coarse-grained metamorphic rock that possesses schistosity. (page 221) |
|
|
Term
|
Definition
| An older, interior region of a continent where "basement" rocks are exposed. (page 232) |
|
|
Term
|
Definition
| The changes that can occur in a rock due to the passage of a shock wave, generally resulting from a meteorite impact. (page 232) |
|
|
Term
|
Definition
| Fine-grained, low-grade metamorphic rock, formed by the metamorphism of shale. (page 221) |
|
|
Term
|
Definition
| The push, pull, or shear that a material feels when subjected to a force; formally, the force applied per unit area over which the force acts. (page 218) |
|
|
Term
|
Definition
| Metamorphism caused by heat conducted into country rock from an igneous intrusion. (page 227) |
|
|
Term
|
Definition
| The succession of events that results in the transformation of Earth materials from one rock type to another, then another, and so on. (page 237) |
|
|
Term
|
Definition
| A distinctive chemical derived from an organism and preserved in rock. Also referred to as a chemical fossil or molecular fossil. (page 330) |
|
|
Term
|
Definition
| The remarkable diversification of life, indicated by the fossil record, that occurred at the beginning of the Cambrian Period. (page 333) |
|
|
Term
|
Definition
| Sediment that preserves the shape of a shell it once filled before the shell dissolved or mechanically weathered away. (page 329) |
|
|
Term
|
Definition
| The broadest divisions of life (Archaea, Bacteria, Eukaryota). (page 332) |
|
|
Term
|
Definition
| The change in populations of life that take place over time, leading to the modification of a given species, and/or to the appearance of new species or extinction of existing species. (page 327) |
|
|
Term
|
Definition
| The death of the last members of a species so that there are no parents to pass on their genetic traits to offspring. (page 336) |
|
|
Term
|
Definition
| A rare fossilized relict, or trace, of the soft part of an organism (page 331) |
|
|
Term
|
Definition
| The remnant, or trace, of an ancient living organism that has been preserved in rock or sediment. (page 327) |
|
|
Term
|
Definition
| The process of forming a fossil. (page 327) |
|
|
Term
|
Definition
| The theory that evolution happens at a constant, slow rate. (page 335) |
|
|
Term
|
Definition
| A high-level taxonomic division of life. Examples are Plantae, Animalia, and Fungi. (page 332) |
|
|
Term
|
Definition
| A fossil large enough to be seen with the naked eye. (page 330) |
|
|
Term
|
Definition
| A time when vast numbers of species abruptly vanish. (page 336) |
|
|
Term
|
Definition
| A fossil that can be seen only with a microscope or an electron microscope. (page 330) |
|
|
Term
|
Definition
| A cavity in sedimentary rock left behind when a shell that once filled the space weathers out. (page 329) |
|
|
Term
|
Definition
The shape of features visible on a fossil.
(page 332) |
|
|
Term
|
Definition
| The process by which the fittest organisms survive to pass on their characteristics to the next generation. (page 335) |
|
|
Term
|
Definition
| A geologist or biologist who studies the fossil record to reconstruct the history of life on Earth. (page 327) |
|
|
Term
|
Definition
| The study of life history through the examination of the fossil record and its relation to the stratigraphic record. (page 327) |
|
|
Term
|
Definition
| The fossilization process in which plant material becomes transformed into rock by the precipitation of silica from groundwater. (page 330) |
|
|
Term
Petrified wood
(the word petrified means turned to stone) |
|
Definition
| Forms when wood is permineralized. (page 330) |
|
|
Term
|
Definition
| A chart representing the ideas of paleontologists showing which groups of organisms radiated from which ancestors. (page 333) |
|
|
Term
|
Definition
| A representation of life evolution showing how populations of the present relate to populations of the past. (page 333) |
|
|
Term
|
Definition
| The likelihood that an organism will be preserved in the fossil record. (page 331) |
|
|
Term
|
Definition
| The hypothesis that evolution takes place in fits and starts; evolution occurs very slowly for quite a while and then, during a relatively short period, takes place very rapidly. (page 335) |
|
|
Term
|
Definition
| The classification of the relationships among different forms of life. (page 332) |
|
|
Term
|
Definition
| The remarkable diversification of life, indicated by the fossil record, that occurred at the beginning of the Cambrian Period. (page 351) |
|
|
Term
|
Definition
| The temperature at which parent and daughter isotopes can no longer escape from a mineral, so the ratio of parents to daughters can be used for isotopic dating. (page 357) |
|
|
Term
|
Definition
| The largest subdivision of geologic time. (page 349) |
|
|
Term
|
Definition
| An interval of geologic time representing the largest subdivision of a period. (page 349) |
|
|
Term
|
Definition
| An interval of geologic time representing the largest subdivision of the Phanerozoic Eon. (page 349) |
|
|
Term
|
Definition
| A group of fossil species found in a specific sequence of sedimentary rock. (page 341) |
|
|
Term
|
Definition
| The sequence of assemblages of fossil species preserved in the stratigraphic record. (page 341) |
|
|
Term
|
Definition
| The science of dating geologic events in years. (page 356) |
|
|
Term
|
Definition
| A composite stratigraphic chart that represents the entirety of the Earth's history. (page 349) |
|
|
Term
|
Definition
| A depositional contact is a type of geologic contact (contact, for short), a broader term used for any boundary between two rock bodies. (page 346) |
|
|
Term
|
Definition
| The sequence of geologic events that has taken place in a region. (page 341) |
|
|
Term
|
Definition
| A map showing the distribution of rock units and structures across a region. (page 349) |
|
|
Term
|
Definition
| The span of time since the formation of the Earth. (page 339) |
|
|
Term
|
Definition
| A scale that describes the intervals of geologic time. (page 359) |
|
|
Term
|
Definition
| The time it takes for half of a group of a radioactive element's isotopes to decay. (page 356) |
|
|
Term
|
Definition
| A fossil species that is widespread and survived for a relatively short duration, and can therefore be used to correlate strata. (page 343) |
|
|
Term
|
Definition
| Different versions of a given element that have the same atomic number but different atomic weights. (page 356) |
|
|
Term
|
Definition
| A method to determine a rock's numerical age by measuring the ratio of parent to daughter isotopes in minerals. (page 356) |
|
|
Term
|
Definition
| (in older literature, 'absolute age') The age of a geologic feature given in years. (page 340) |
|
|
Term
|
Definition
| An interval of geologic time representing a subdivision of a geologic era. (page 349) |
|
|
Term
|
Definition
| The interval of geologic time between Earth's formation about 4.57 Ga and the beginning of the Phanerozoic Eon 542 Ma. (page 349) |
|
|
Term
|
Definition
| The process by which a radioactive atom undergoes fission or releases particles, thereby being transformed into a new element. (page 356) (the nucleus of an unstable atom loses energy by emitting radiation) |
|
|
Term
|
Definition
| An element that undergoes radioactive decay reactions that yield a different element. (page 352) |
|
|
Term
| Isotopic (Radiometric) dating |
|
Definition
| The science of dating geologic events in years by measuring the ratio of parent radioactive atoms to daughter product atoms. (page 356) |
|
|
Term
|
Definition
| The age of one geologic feature with respect to another. (page 340) |
|
|
Term
|
Definition
| A cross-section diagram of a sequence of strata summarizing information about the sequence. (page 346) |
|
|
Term
| Stratigraphic correlation |
|
Definition
| Comparison of layers of sedimentary and igneous rock of the same age and relating them to subdivisions on a single stratigraphic scale. (page 348) |
|
|
Term
|
Definition
| A recognizable layer of a specific sedimentary rock type or set of rock types, deposited during a certain time interval, that can be traced over a broad region. (page 346) |
|
|
Term
|
Definition
| Several adjacent stratigraphic formations in a succession. (page 346) |
|
|
Term
|
Definition
| A boundary between two different rock sequences representing an interval of time during which new strata were not deposited and/or were eroded. (page 344) |
|
|
Term
|
Definition
| A geologic principle stating that processes that can be observed today also happened in the past, at comparable rates, and can explain features preserved in the geologic record. Put simply, the present is the key to the past. (page 340) |
|
|
Term
|
Definition
| Precipitation in which air pollutants react with water to make a weak acid that then falls from the sky. (page 415) |
|
|
Term
|
Definition
| Gas or liquid fuel made from plant material (biomass). Examples include alcohol (from fermented sugar), biodiesel from vegetable oil, and wood. (page 411) |
|
|
Term
|
Definition
| The amount of organic material in a specified volume. (page 392) |
|
|
Term
|
Definition
| Hydrocarbons rush out of a well in an uncontrolled fashion. (page 416) |
|
|
Term
|
Definition
| Mineral material that precipitates from water and fills the spaces between grains, holding the grains together. (page 423) |
|
|
Term
|
Definition
| A self-perpetuating process in a nuclear reaction, whereby neutrons released during the fission trigger more fission. (page 409) |
|
|
Term
|
Definition
| A black, organic rock consisting of greater than 50% carbon; it forms from the buried and altered remains of plant material. (page 403) |
|
|
Term
|
Definition
| The process of producing relatively clean-burning gases from solid coal. (page 407) |
|
|
Term
|
Definition
| A measurement of the carbon content of coal; higher-rank coal forms at higher temperatures. (page 406) |
|
|
Term
|
Definition
| The quantities of discovered, but not yet mined, coal in sedimentary rock of the continents. (page 406) |
|
|
Term
|
Definition
| A hydrocarbon reserve that can be extracted simply by pumping from a reservoir rock. (page 394) |
|
|
Term
|
Definition
| An intact block of granite or marble to be used for architectural purposes. (page 422) |
|
|
Term
|
Definition
| The process of controlling the trajectory of a drill bit to make sure that the drill hole goes exactly where desired. (page 399) |
|
|
Term
|
Definition
| A vertical pipe in which crude oil is separated into several components. (page 400) |
|
|
Term
|
Definition
| A slurry of water mixed with clay that oil drillers use to cool a drill bit and flush rock cuttings up and out of the hole. (page 399) |
|
|
Term
|
Definition
| The capacity to do work. (page 392) |
|
|
Term
|
Definition
| The amount of energy that can be produced per unit mass of a fuel. (page 393) |
|
|
Term
|
Definition
| The configuration of power-generating sources, power lines, and transformers that distributes electrical power nationally. (page 415) |
|
|
Term
|
Definition
| Something that can be used to produce work; in a geologic context, a material (such as oil, coal, wind, flowing water) that can be used to produce energy. (page 391) |
|
|
Term
|
Definition
| An energy resource such as oil or coal that comes from organisms that lived long ago and thus stores solar energy that reached the Earth then. (page 392) |
|
|
Term
|
Definition
| A transportable substance that can serve a supply of energy. (page 392) |
|
|
Term
|
Definition
| Describes the concentration of a useful metal in ore. (page 418) |
|
|
Term
|
Definition
| The point on a production graph showing a resource plotted against time, at which the rate of production levels off and starts to decrease. (page 414) |
|
|
Term
|
Definition
| A chain-like or ring-like molecule made of hydrogen and carbon atoms; petroleum and natural gas are examples. (page 393) |
|
|
Term
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Definition
| A process in which oil shale warms to temperatures of greater than about 90°C so kerogen molecules transform into oil and natural gas molecules. (page 394) |
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Term
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Definition
| A known supply of oil and gas held underground. (page 394) |
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Term
| Hydrofracturing (Fracking) |
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Definition
| A process by which drillers generate new fractures or open preexisting ones underground, by pumping a high-pressure fluid into a portion of the drill hole, in order to increase the permeability of surrounding hydrocarbon-bearing rocks. (page 400) |
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Term
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Definition
| The waxy molecules into which the organic material in shale transforms on reaching about 100°C. At higher temperatures, this material transforms into oil. (page 394) |
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Term
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Definition
| The melting of the fuel rods in a nuclear reactor that occurs if the rate of fission becomes too fast and the fuel rods become too hot. (page 409) |
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Term
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Definition
| A solid composed almost entirely of atoms of metallic elements; it is generally opaque, shiny, smooth, malleable, and can conduct electricity. (page 417) |
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Term
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Definition
| The movement of hydrocarbons from source rocks to reservoir rocks. (page 395) |
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Term
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Definition
| Extracted from the Earth's upper crust for practical purposes. (page 391) |
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Term
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Definition
| The part of a nuclear power plant where the fission reactions occur. (page 409) |
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Term
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Definition
| The period of human history, including our own, so named because the economy depends on oil. (page 413) |
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Term
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Definition
| A location at the surface of the Earth where hydrocarbons are being released from underground naturally. (page 395) |
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Term
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Definition
| Shale containing kerogen. (pages 394, 402) |
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Term
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Definition
| The narrow range of temperatures under which oil can form in a source rock. (page 394) |
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Term
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Definition
| Rock containing native metals or a concentrated accumulation of ore minerals. (page 418) |
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Term
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Definition
| An economically significant accumulation of ore. (page 418) |
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Term
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Definition
| Minerals that have metal in high concentrations and in a form that can be easily extracted. (page 417) |
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Term
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Definition
| Compacted and partially decayed vegetation accumulating beneath a swamp. (page 405) |
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Term
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Definition
| The degree to which a material allows fluids to pass through it via an interconnected network of pores and cracks. (page 395) |
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Term
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Definition
| A small, open space within sediment or rock. (page 395) |
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Term
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Definition
| The total volume of empty space (pore space) in a material, usually expressed as a percentage. (page 395) |
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Term
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Definition
| Cement made by mechanically mixing limestone, sandstone, and shale in just the right proportions, before heating in a kiln, to provide the correct chemical makeup of cement. (page 423) |
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Term
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Definition
| Rock with high porosity and permeability, so it can contain an abundant amount of easily accessible oil. (page 395) |
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Term
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Definition
| A rising bulbous dome of salt that bends up the adjacent layers of sedimentary rock. (page 397) |
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Term
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Definition
| A relatively impermeable rock, such as shale, salt, or unfractured limestone, that lies above a reservoir rock and stops the oil from rising further. (page 395) |
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Term
| Seismic-reflection profile |
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Definition
| A cross-sectional view of the crust made by measuring the reflection of artificial seismic waves off boundaries between different layers of rock in the crust. (page 398) |
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Term
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Definition
| Gas that comes directly from organic shale. (page 401) |
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Term
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Definition
| Oil that is still residing in shale, a source rock. (page 401) |
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Term
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Definition
| A device that can produce electricity directly from incoming solar energy. (page 412) |
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Term
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Definition
| A rock (organic-rich shale) containing the raw materials from which hydrocarbons eventually form. (page 393) |
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Term
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Definition
| A mineral containing elements of importance to technology (particularly to the military). (page 424) |
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Term
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Definition
| Sandstone reservoir rock in which less viscous oil and gas molecules have either escaped or been eaten by microbes, so that only tar remains. (page 402) |
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Term
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Definition
| Energy produced by the daily rise and fall of the tides; people can utilize this energy, for example, by damming a bay or estuary, so that water passes through turbines when the tide changes. (page 411) |
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Term
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Definition
| A subsurface configuration of seal rocks and structures that keep oil and/or gas underground, so it doesn't seep out at the surface. (page 395) |
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Term
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Definition
| An accumulation of hydrocarbons that are too viscous to flow, and/or that occur in impermeable rock, so that they cannot be pumped simply by drilling a well (examples -- tar sand, oil shale, shale oil/gas). (page 394) |
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Term
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Definition
| The extraction of ore or coal by digging shafts and tunnels underground. (page 407) |
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