Dolerite


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Related to Dolerite: pegmatite

Dolerite

 

a magmatic rock, effusive or intrusive (near the surface), with a basalt composition. It is characterized by a holocrystalline, coarse-grained doleritic (or ophitic) structure; an aggregate of pyroxene (frequently with olivine) in the form of isometric grains fills out the angular sections between prisms of plagioclase. Dolerite is formed as a result of the slow cooling of molten basalt in the central parts of lava flows or in veins. Dolerite is used in construction as dimension stone and to make crushed stone.

References in periodicals archive ?
Based on industrial seismic data the size of the presumable area in which dolerite intrusions occur ranges from 30 to 60 km in east-west direction, and is about 100 km in north-south direction (Fig.
A recent re-analysis of published geochemical data suggests at least three main kinds of dolerite are represented at Stonehenge, with Carn Goedog on the northern side of the ridge providing the closest match for just over half of the samples examined.
The dolerite is orthopyroxene-bearing quartz tholeiite of an "HTQ" type, and its age, mineralogy, chemistry, and geographic extent indicate that the Christmas Cove Dyke is contiguous and co-magmatic with the Onway Dyke of southern New Hampshire, the Holden Dyke of Massachusetts, the Higganum Dyke of southern New England, and probably dykes in southern New Brunswick, Canada; all parts of a giant dyke system at least 700 km long.
The Basement Complex rocks of Nigeria are composed predominantly of migmatite gneiss complex; slightly migmatised to unmigmatised paraschists and metaigneous rocks; charnockitic, older granite suites and unmetamorphosed dolerite dykes.
Drilling intersected broad zones of gold mineralisation associated with a wedge of felsic volcanics bounded by dolerite.
1994), Paleogene basalt flows and dolerite sills have been encountered within the Lafia formation.
The note adds: 'The hill is a dome-shaped mass of dolerite, a hard, grey/ black igneous rock formed underneath what was once the Dudley Volcano.
The project area is dominated by Achaean granite and granite gneiss (commonly laterised) with minor units of metasediment, meta-volcanics and Proterozoic dolerite dykes.
The striking rock formation, composed of massive columns of dolerite, has been compared to the appearance of pleats in a tartan kilt.
Mixed with dolerite it flows, two stones in endothermic coupling.
This mountain in the Cradle Mountain-Lake St Clair National Park is made of dolerite columns.