microsphorite (mi-cros'-pho-rite). Primary in situ microcrystalline phosphorite of the central Florida phosphate district. Disrupted and fragmented, it forms clastic particles that are the most common form of phosphorite in the sediments (Freas and Riggs, 1968).
GeoWord of the Day
The GeoWord of the Day is a free service of the American Geosciences Institute. All of the terms and definitions are from the Glossary of Geology, 5th Edition Revised.
oxbow (ox'-bow). (a) A closely looping stream meander resembling the U-shaped frame embracing an ox's neck, having an extreme curvature such that only a neck of land is left between two parts of the stream. Syn: horseshoe bend. (b) A term used in New England also for the land enclosed, or partly enclosed, within an oxbow (bend of a stream). (c) The abandoned, bow- or horseshoe-shaped channel of a former meander, left when the stream formed a cutoff across a narrow meander neck. See also: cutoff meander. Syn: abandoned channel. (d) oxbow lake.
mikasaite . A white to light brown rhombohedral mineral: (Fe3+,Al)2(SO4)3. It is the Fe3+ analogue of millosevichite.
spangolite (span'-go-lite). A dark green trigonal mineral: Cu6Al(SO4)Cl(OH)12•3H2O .
calc-flinta (calc-flin'-ta). A fine-grained calc-silicate rock of flinty appearance formed by thermal metamorphism of a calcareous mudstone, possibly with some accompanying pneumatolytic action. Rarely used.
clinker [coal] (clink'-er). (a) Coal that has been altered by igneous intrusion. Cf: natural coke. Syn: scoria [coal]. (b) Masses of coal ash that are a byproduct of combustion. Cf: coke.
raguinite (ra-guin'-ite). A metallic bronze monoclinic mineral: TlFeS2 .
rock-glacier creep (rock'-gla-cier). The slow creep of tongues of rock glaciers.
spectral reflectance . Reflectance measured at a specific wavelength.
rand . (a) An English term for the low, marshy border of a lake or of a river overgrown with reeds. (b) A term used in South Africa for a long, low, rocky ridge or range of hills often covered with scrub; e.g. Witwatersrand (popularly contracted to "The Rand"), a ridge containing rich gold-bearing rocks, 100 km long, situated near Johannesburg.
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