Crossword clues for diabase
diabase
The Collaborative International Dictionary
Diabase \Di"a*base\, n. [F. diabase, fr. Gr. ? a crossing or passing over, fr. ?; ? + ? to go; -- so called by Brongniart, because it passes over to diorite.] (Min.) A basic, dark-colored, holocrystalline, igneous rock, consisting essentially of a triclinic feldspar and pyroxene with magnetic iron; -- often limited to rocks pretertiary in age. It includes part of what was early called greenstone.
Wiktionary
n. (context geology English) A fine-grained igneous rock composed mostly of pyroxene and feldspar
Wikipedia
Diabase or dolerite or microgabbro is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine grained to aphanitic chilled margins which may contain tachylite (dark mafic glass). Diabase is the preferred name in North America, dolerite is the preferred name in most of the rest of the world, where sometimes the name diabase is applied to altered dolerites and basalts, though many petrologists prefer the name microgabbro to avoid this confusion.
Usage examples of "diabase".
Shergotty and Zagami meteorites show that both diabase stones consist mainly of the pyroxenes pigeonite and augite, and of maskelynite, a shocked plasgioclase glass.
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.
In situ investigation of the brecciated diabase in SNC Crater and surrounding region reveal that ilmenite and whitlockite are missing from this inventory.
Studies at another oval crater about the same age and size, Crater Tf, on the Elysium Massif show that it has the same brecciated diabase, with the same phase accessories, as SNC Crater and environs.
Sarsen, three edged hammer-stones of flint, one Sarsen and one Diabase hammer-stone, were found at depths varying between two feet and four feet.
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.
The Crater Tf diabase also exhibits a poikilitic texture like that seen in the Chassigny meteorite (Banin, Clark, and Wänke, 1992).
The Crater Tf diabase also exhibits a poikilitic texture like that seen in the Chassigny meteorite (Banin, Clark and Wanke, 1992).