lamprophyre

/lam-pruh-fahyuhr/US // ˈlæm prəˌfaɪər //UK // (ˈlæmprəˌfaɪə) //

斑点

Definitions

n.名词 noun

1
Petrology.
- : any dark intrusive rock in which dark minerals occur both as phenocrysts and as groundmass.

Each variety of lamprophyre may and often does contain all four minerals but is named according to the two which preponderate.
It is supposed that they did not crystallize in the lamprophyre dike but in some way were caught up by it.
In Fergus County, Montana, they are mined from decomposed dikes of lamprophyre (a basic igneous rock).
They are found mostly as loose crystals in gravel, but are known also in igenous rocks like andesite and lamprophyre.