diabase

[ dahy-uh-beys ]

Phonetic (Standard)IPA

noun

, Petrology.

a fine-grained gabbro occurring as minor intrusions.
British. a dark igneous rock consisting essentially of augite and feldspar; an altered dolerite.

diabase

/ ˈdaɪəˌbeɪs /

diabase

/ dī′ə-bās′ /

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.
Also called dolerite

Origin of diabase¹

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

Origin of diabase¹

C19: from French, from Greek diabasis a crossing over, from diabainein to cross over, from dia- + bainein to go

They are holocrystalline in form and true glassy bases are rare, rendering the term diabase more appropriate than basalt.

While the diabase dikes are most prominent in the Newark rocks, they are also found occasionally in the other terraces.

The diabase occurs only as an intrusive rock in the vicinity of the Catoctin Belt.

None the less, its origin as diabase can definitely be asserted of the whole mass.

Dynamic alteration of the Catoctin diabase is pronounced and wide-spread.

April 18, 2024petrichor

[pet-ri-kawr]

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