diabase

American  

[dahy-uh-beys] / ˈdaɪ əˌbeɪs /

noun

Petrology.

1. a fine-grained gabbro occurring as minor intrusions.

2. British. a dark igneous rock consisting essentially of augite and feldspar; an altered dolerite.

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diabase British  

/ ˈdaɪəˌbeɪs /

noun

1. an altered dolerite

2. another name for dolerite

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diabase Scientific  

/ dī′ə-bās′ /

1. A dark-gray to black, medium-grained igneous rock consisting mainly of labradorite and pyroxene. Diabase is compositionally similar to andesite, but has coarser grains. It is commonly found in sills and dikes.

2. Also called dolerite

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Other Word Forms

• diabasic
  adjective

Etymology

Origin of diabase

1810–20; < French, equivalent to dia- (error for di- two) + base base ¹

Example Sentences

It is found in the greenstone and hornblende-schists of Batallack Head near St Just in Cornwall, and in diabase in the Harz; and small ones in Maine and in Northampton county, Pennsylvania, U.S.A.

From Encyclopaedia Britannica, 11th Edition, Volume 3, Part 1, Slice 1 "Austria, Lower" to "Bacon" by Various

Lenticular intercalations of gabbro, diabase, &c., occur in the Flysch in Calabria on the Pyrenees.

From Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 5 "Fleury, Claude" to "Foraker" by Various

Among the stones in the drift at these exposures are limestone, sandstone, quartzite, diabase, gabbro, gneiss, granite, schist, and porphyry, together with pieces of flint and chert.

From The Geography of the Region about Devils Lake and the Dalles of the Wisconsin by Atwood, Wallace W.

At Carrock Fell, N.E. of Skiddaw, is an extremely interesting complex of volcanic rocks, and in many other places are diabase and other forms, e.g. the well-known rock at Castle Head, Keswick.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 8 "Cube" to "Daguerre, Louis" by Various

The best-known locality is Fronolen near Tremadoc in North Wales, where crystals of the thin tabular habit occur with crystallized quartz, albite and anatase on the walls of crevices in diabase.

From Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 "Brescia" to "Bulgaria" by Various