179. Geology

See also 133. EARTH ; 283. MOUNTAINS ; 385. STONES ; 411. VOLCANOES .

aerogeology

the use of aerial observation and photography in the study of geological features. — aerogeologist, n. — aerogeologic, aerogeological, adj.

agrogeology

the branch of geology concerned with the adaptability of land to agriculture, soil quality, etc.

anamorphism

metamorphism from simple to more complex minerals, usually occurring deep beneath the earth’s surface. See also katamorphism , metamorphism . — anamorphic, anamorphotic, adj.

aphanitism

a minuteness of rock texture so fine that individual grains are invisible to the naked eye. — aphanite, n.

archeogeology, archaeogeology

the branch of geology that studies the geological formations of the remote past. — archeogeologic, archaeogeologic, archeogeological, archaeogeological, adj.

brecciation

the formation of breccia, or masses of rock composed of fragments of older rock fused together.

brontolith, brontolite

a thunderstone or meteoric rock.

catastrophism

the theory that geological changes have been caused by sudden upheaval rather than by gradual and continuing processes. Cf. uniformitarianism. — catastrophist, n.

clinometry

the measurement of the elevations and slopes of mineral strata or of cuttings into rock formations. — clinometer, n. — clinometric, clinometrical, adj.

coprolite

a small mass of rock composed of the petrified fecal remains of animals.

crustalogy

the study of surface of the earth or the moon.

diastrophism

the process of movement that causes the earth’s crust to form continents, mountains, etc. — diastrophic, adj.

diluvianism

a geological theory that maintains that some geological phenomena can be explained by extensive flooding of large areas of the earth’s surface or by an equally strong condition of the weather.

epeirogeny, epeirogenesis

the vertical movement or tilting of the earth’s crust, affecting broad expanses of continents. — epeirogenic, epeirogenetic, adj.

epigenesis

the process of metamorphism. See also 44. BIOLOGY ; 122. DISEASE and ILLNESS . — epigenetic, adj.

fluvialist

one who considers geological phenomena to be the result of the action of streams.

geognosy

a branch of geology that studies the constituent parts of the earth, its atmosphere and water, its crust, and its interior condition. — geognosist, geognost, n. — geognostic, adj.

geotectology

the branch of geology that studies the structure of the earth’s crust; structural geology. Also called geotectonics. — geotectonic, adj.

geothermometry

the branch of geology that measures temperatures deep below the surface of the earth; geologic thermometry.

glaciology

the branch of geology that studies the nature, distribution, and movement of glaciers and their effects upon the earth’s topography. — glaciologist, n. — glaciological, adj.

homotaxis, homotaxy

the condition of being arranged in the same way, especially stratified layers that are similar in arrangement and place but not contemporaneous. — homotaxic, adj.

hydrogeology

the study of water both on and beneath the earth’s surface. — hydrogeological, adj.

isostasy

the general equality of pressure in the crust of the earth. — isostatic, adj.

katamorphism

metamorphism from complex to simpler minerals, usually occurring at or near the earth’s surface. See also anamorphism, metamorphism. — katamorphic, adj.

lapillus

a small stone ejected by a volcano.

limnology

the branch of geology that studies ponds and lakes. — limnologist, n.

lithification

the process by which loose mineral fragments or particles of sand are solidifled into stone.

lithogenesy

the science of explaining the minerals of which the earth is composed, their origins, and the cause of their form and arrangement.

lithoidology

Rare. the study of rocks.

lithology

the branch of geology that studies the mineral composition and structure of rocks, usu. macroscopically. Cf. petrography. — lithologic, lithological, adj.

lithotome

a rock or stone formed by natural processes in such a way that it appears to have been artificially fashioned.

metamorphism

1 . the process of change in the form and structure of rocks by the agency of heat, water, and pressure.

2 . the change of particular types of rock, as limestone into marble. Also called epigenesis. See also 74. CHANGE . — metamorphic, adj.

metasomatism

the process of chemical change in rocks or other mineral masses that results in the formation of new rocks or minerals. Also metasomatosis.

microlith

1 . a very small isotropic needlelike crystal, found usually in volcanic rocks.

2 . a very small stone tooi or part of a tool, as a tooth of a primitive saw. — microlithic, adj.

mineralogy

the branch of geology that studies the physical and chemical structures of minerals. — mineralogist, n. — mineralogic, mineralogical, adj.

neptunism

the now obsolete theory that all rock surfaces were formed by the agency of water. Cf. plutonism . — neptunist, n.

orogeny

the process by which mountains are created. — orogenic, orogenetic, adj.

oryctology

mineralogy. Also called oryctognosy.

paleopedology, palaeopaedology

a branch of soil science that studies the soils of past geologie times. — paleopedologist, palaeopaedologist, n. — paleopedologic, palaeopaedologic, paleopedological, palaeopaedological, adj.

perimorphism

a phenomenon in which one mineral encloses another. — perimorphic, perimorphous, adj.

petrogensis, petrogeny

the branch of petrology that studies the formation of rocks.

petrography

the branch of geology that describes and classifies rocks, usually after microscopic study. Cf. lithology . — petrographer, n. — petrographic, petrographical, adj.

petrology

the branch of geology that studies the origin, structure, composition, changing, and classification of rocks. — petrologist, n. — petrologic, petrological , adj.

plutonism

the theory that all rock surfaces have solidified from magmas, some at great depths below the surface of the earth. Cf. neptunism. — plutonist, n.

pneumatolysis

the process by which ores and minerals are formed from the action of vapors produced by igneous magmas. — pneumatolytic, adj.

pyritology

the study of iron or copper sulfides, called pyrites.

regolith

the layer of disintegrated and decomposed rock fragments, including soil, lying above the solid rock of the earth’s crust. Also called mantle rock.

stratigraphy

the branch of geology that studies the classification, correlation, and interpretation of stratified rocks. — stratigrapher, n. — stratigraphic, stratigraphical, adj.

tectonics

the study of the structure and behavior of the earth’s crust. — tectonic , adj.

uniformitarianism

the thesis that early geological processes were not unlike those observed today, i.e., gradually occurring. Cf. catastrophism. — uniformitarian, n.

xenolith

a fragment of rock embedded in another kind of rock.