Occurence and petrology of lamprophyres from the Northern part of the Ditrău alkaline massif, Eastern Carpathians, Romania

Lamprophyre dykes and dyke swarms exposed in the northern part of the Ditràu Alkaline Massif (DAM) intersect granitoids, syenitoids, hornblendites and diorites. Accordingly to the lamprophyres geological conditions, they are the last stage of the DAM's magmatic evolution. Most of the lamprophyr...

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Bibliographic Details
Main Authors: Batki Andrea
Pál Molnár Elemér
Bárdossy Apolka
Format: Article
Published: Department of Mineralogy, Geochemistry and Petrology, University of Szeged Szeged 2004
Series:Acta mineralogica-petrographica 45 No. 2
Kulcsszavak:Földtan, Ásványtan, Kőzettan
Subjects:
Online Access:http://acta.bibl.u-szeged.hu/25129
Description
Summary:Lamprophyre dykes and dyke swarms exposed in the northern part of the Ditràu Alkaline Massif (DAM) intersect granitoids, syenitoids, hornblendites and diorites. Accordingly to the lamprophyres geological conditions, they are the last stage of the DAM's magmatic evolution. Most of the lamprophyres are composed of phenocrysts of augite which are included in a matrix consisting of fine-grained kaersutiteferrokaersutite, hastingsite-magnesiohastingsite, biotite and interstitial albite-oligoclase-andesine. Other lamprophyre varieties have augite and/or melanite phenocrysts. Their microcrystalline groundmass is composed of mainly arfvedsonite, biotite, albite-oligoclase and orthoclase. Both lamprophyre types contain felsic globular structures filled with carbonatic and/or feldspathic minerals. Mineral assemblage and major element geochemical composition indicate that they are camptonites within alkaline lamprophyres and kersantites within calcalkaline lamprophyres.
Physical Description:21-27
ISSN:0365-8066