Occurrence and petrology of lamprophyres from the northern part of the Ditrau Alkaline Massif, Eastern Carpathians, Romania
Reference:
Acta Mineralogica-Petrographica, Szeged 2004, Vol. 45/2, pp. 21-28
Szerző:
Batki Anikó
Dr. Pál-Molnár Elemér
Bárdossy Apolka
Abstract:
Lamprophyre dykes and dyke swarms exposed in the northern part of the Ditr u 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.
acta2004, camptonite, Ditrau Alkaline Massif, Eastern Carpathians, kersantite, Romania
