Publication at Faculty of Science, Central Library of Charles University |
2009
Abstract
The Říčany pluton represents an elliptical shallow-level intrusion made up of outer, more fractionated, strongly porphyritic granite and inner, less evolved, weakly porphyritic granite. Mesoscopic foliation defines an onion-skin pattern and corresponds well with the magnetic (AMS) foliations.
Magnetic lineation plunges shallowly (0-20°) and is sub-parallel to the contact in the outer part of the pluton, whereas in the pluton center lineation dips steeply (60-70°) with variable trends. We interpret the fabrics in the pluton as being a result of helical flow, whereby faster subvertical flow in low-viscosity pluton center generated subhorizontal flow in outer, higher-viscosity (phenocryst-rich) margin.