Publisher © Czech Geological Survey, ISSN: 2336-5757 (online), 0514-8057 (print)

Mafic microgranular enclaves in the Sedlčany granite (Central Bohemian Plutonic Complex) and their relationship to dyke rocks

 

František Holub

Geoscience Research Reports 43, 2010 (GRR for 2009), pages 211–214
Map sheets: Sedlčany (22-22)

Full text (PDF, 0.26 MB)

 

Abstract

The Sedlčany intrusion (Central Bohemian Plutonic Complex) is built by amphibole-bearing biotite monzogranite rich in MgO and K2O. Mafic microgranular enclaves (MME) are even more potassic and share some geochemical features with ultrapotassic plutonites of the durbachite series and also minettes forming dykes in the adjacent older granitoid intrusions of the high-K calc alkaline suite. However, the MME display geochemical variations different from the theoretical mixing trend and thus cannot be derived from minette magmas by hybridization process. The enclave-granite compositional differences appear to be governed by crystal-liquid equilibria.