- a fine-grained gabbro occurring as minor intrusions.
- British. a dark igneous rock consisting essentially of augite and feldspar; an altered dolerite.
Origin of diabase
1810–20; < French, equivalent to dia- (error for di- two) + base base1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for diabase
Quartz porphyry, diabase and diorite appear in the Ardennes.
The minerals of diabase are the same as those of dolerite, viz.
One, a complete specimen composed of a diabase, was shaped by pecking followed by grinding.The Topanga Culture Final Report on Excavations, 1948
A. E. Treganza
In Arizona chrysotile is found in veins in cherty limestone, associated with diabase intrusives.The Economic Aspect of Geology
C. K. Leith
At St Andreasberg in the Harz it occurs both in diabase and in the veins of silver ore.
- British an altered dolerite
- US another name for dolerite
C19: from French, from Greek diabasis a crossing over, from diabainein to cross over, from dia- + bainein to go
- 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
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