lamprophyre
lamprophyre A dark-coloured, strongly
porphyritic,
intrusive igneous rock, containing abundant
euhedral phenocrysts of
biotite and/or
amphibole which can be accompanied by phenocrysts of
olivine,
diopside,
apatite, or opaque oxides, set in a
mafic,
felsic, or glassy
groundmass. There are no felsic phenocrysts present in this rock type. The lamprophyres are subdivided into a number of types on the basis of their most abundant mafic component and the presence and type of feldspar in the groundmass. Lamprophyre types include
minette,
kerstantite,
alnöite,
vogesite,
camptonite, and
monchiquite, and are found intruded as
dykes and
sills.
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Robert Stewart Castlereagh, 2d Viscount
Book article from: The Columbia Encyclopedia, Sixth Edition
Robert Stewart Castlereagh, 2d Viscount , 1769-1822, British statesman...of his colleague George Canning to Castlereagh's policies flared into a serious...for them. He became (1821) the 2d marquess of Londonderry on his father...
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Viscount Castlereagh
Encyclopedia entry from: Encyclopedia of World Biography
Viscount Castlereagh The British statesman Robert Stewart Viscount Castlereagh and 2d Marquess of Londonderry (1769-1822), as foreign...remarkably durable European peace settlement. Robert Stewart was born in Ulster on June 18, 1769...
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Robert Stewart Londonderry, 2d marquess of
Book article from: The Columbia Encyclopedia, Sixth Edition
Robert Stewart Londonderry, 2d marquess of see Castlereagh, Robert Stewart, 2d Viscount .
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