Terms, geological

The geological term, uranium occurrence, implies a naturally occurring anomalous concentration of uranium. The term, uranium deposit, implies a mass of naturally occurring mineral material from which uranium could be exploited at present or in the future. An often-encountered term in uranium mineralogy is uranium ore mineral. It is a mineral having such physical and chemical properties and occurring in a deposit in such concentra-... 

One more important property of Jupiter must be mentioned the Earth owes its relatively quiet periods (in geological terms) to the huge gravitational force of the giant planet. Jupiter attracts most of the comets and asteroids orbiting in its vicinity, thus protecting the Earth from impact catastrophes ... 

Selenium is an essential trace element for optimal health but an excess is toxic. The British population is now reckoned to be selenium deficient because more European wheat is now used to make bread at the expense of North American wheat. The difference in the selenium content is caused by the difference in the selenium content of the soils. In geological terms, European soil is older and the selenium has washed out. 

Page, D. (1865). Handbook of Geological Terms. Blackwood and Sons, Edinburgh. 

Bates, R.C. Jackson, J.A., Eds. Dictionary of Geological Terms, 3rd Edition, American Geological Institute Doubleday New York, NY, 1984. Wade, L.G.Jr. Organic Chemistry, Prentice Hall, Inc. New Jersey, USA,... 

Suspended particles in surface waters are eventually either transported out of the water body (e.g., carried to the ocean by a river) or deposited on the bottom of the water body by settling. Settling is especially important in relatively quiescent waters, such as lakes, which typically have a relatively short life span (as measured in geologic terms) because they tend to fill in with... 

The oldest known prokaryotic microfossils are approximately 3.5 billion years old. Consequently, life must have emerged between 3.5 and four billion years ago [2]. This was, in geological terms, only a short time after the Earth had... 

Geochemical evidence suggests that caprock leakage in Halten Vest must have occurred, in geological terms, very recently, and after the build up of overpressure which took place during the past 3Ma due to the accelerated burial (cf. Vik et al. 1991) and in response to accelerated diagenesis on deep faults. 

The last glacial period ended about 10,000 years ago, and given the typical length of interglacial periods of about 10,000 years, onset of glacial conditions would normally be imminent in geological terms. Indeed, until 20 years ago, the... 

Calcite is metastable with respect to dolomite in the presence of sea-water (which contains dissolved magnesium). The process of dolomitisation is slow, even in geological terms. It is, however, slowly reversed in the presence of fresh water. 

In geological terms, coal is often defined as banded, streaky, black mineral which is readily combustible and contains more than 50% (by weight) or 70% (by volume) of carbonaceous material. However, to be considered as coal, the black rock must substantially be a deposit of compacted, decayed plant material. 

Kearny, Philip, ed. The Encyclopedia of the Solid Earth Sciences. London Blackwell Science, 1994. Contains an alphabetical list of defined geologic terms, minerals, and geologic concepts. 

In geological terms, the earth is regarded as consisting of three concentric layers an inner core consisting mainly of iron and nickel, a... 

Feldspars occiu as solid solutions between their principal end member (Na, K, or Ca) compositions. Commercial products in most cases are employed for their chemistry (almninum and alkah content) and are generally characterized aeeordingly. Certain produets are more broadly described in geological terms. 

Smectites are water swellable clays that have a platy structure. Smectite is the mineralogical term for a group of clays, which includes montmorillonite, hectorite, and saponite. Most smectites are more commonly known under the geological term bentonite. By convention, bentonite is understood to be an ore or product with a substantial smectite content. The range of possible chemical variations in the basic smectite trilayer lattice starts with montmorillonite, the high-aluminum end member. Montmorillonite is composed of a central alumina octahedral layer sandwiched between tetrahedral silica layers. This is identical to the dioctahedral pyrophyllite structure except for small... 

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