Field Report. Field Trip to Poland May 2008

Leader : Padhraig Kennan

The trip centred on two areas in Southern Poland, the Variscan Karkonosze Granite in the western Sudetes on the northern margin of the Bohemian Massif and the Carpathian Tatra Mountains with their Variscan core and Alpine nappes. The two areas straddle the southern border of Poland with Czechia and Slovakia, respectively. On our first afternoon in Wroclaw, after having lunch Ð for which we paid according to the total weight of what we chose – Professor Michal Mierzjerewski led us on a short tour of the institute of Geological Sciences, in the old University of Wroclaw and the nearby Cathedral. The next three days were spent with Michal looking at the granite of the ~330Ma Karkonosze pluton (similar in age to, but younger than, the Leinster granite in Wicklow). We learned that granites are not all the same. Most of us had thought granite was simply quartz, feldspars and micas. We learned that the granite material rose through a conduit from below into the upper crust where it spread sideways as thin sheets before cooling and solidifying. Many granites have vertical sections that are mushroom- shaped.

(more…)

Field Report. Field Trip to Belmullet Sat 21st / Sun 22nd June 2008

Leader : Julian Menuge (UCD)

As the forecast predicted, Saturday morning was overcast and uninviting. A large gang met at the Broadhaven Bay Hotel and Julian gave out a very well composed handout in glorious Technicolour. We were to visit five locations around the Belmullet peninsula and a further location near the Ceide Fields. We moved off in a reduced number of cars to Annagh Head to view the spectacular outcrops of Proterozoic rocks of the Grenvillian Orogeny. These metamorphic rocks, gneisses, amphibolites, migmatites, associated pegmatites and metadolerites range in age from 1,753 Ma to 460 Ma, through Grampian orogenic times, and have seen serious metamorphic changes at various times throughout this period. (more…)