Quantitative structural analyses and numerical modelling of ...

278 K. SCHULMANN ET AL.Fig. 4. P–T conditions for (a) peak metamorphism in the orogenic root and Brunia continent south of the Elbe Zone; (b) peakmetamorphism in the orogenic root and Brunia continent north of the Elbe Zone; (c) retrograde conditions in the orogenic rootand Brunia continent south of the Elbe Zone; and (d) retrograde conditions in the orogenic root and Brunia continent north of theElbe Zone. Source of data: Carswell & O¢Brien (1993), Steltenpohl et al. (1993), Medaris et al. (1995), Sˇtı´ pska´ & Schulmann (1995),Bro¨ cker & Klemd (1996), Kryza et al. (1996), Pitra & Guiraud (1996), Parry et al. (1997), Petrakakis (1997), Medaris et al. (1998),Klemd & Bro¨ cker (1999); Romanova´ &Sˇtı´ pska´ (2001); Konopa´ sek et al. (2002); OÕBrien & Ro¨ tzler (2003); Sˇtı´ pska´ et al. (2004); Lexaet al. (2005); Sˇtı´ pska´ & Powell (2005a,b); Racek et al. (2006); Sˇtı´ pska´ et al. (2006); Tajcˇmanová et al. (2006); also shown are steadystategeotherms calculated for various mantle heat flows (as indicated in the figure) and exponential radioactive heat production.commonly re-equilibrated in the stability field ofcordierite at conditions around 4.5–6 kbar and 600–720 °C (Petrakakis, 1997), inferred to be due to thethermal effect of Carboniferous intrusions emplacedat 330)310 Ma (Fig. 3e). Despite the overall medium-pressurecharacter, in the Moldanubian domainthe Varied and Monotonous Group rocks includerare lenses of eclogite that register conditions of 13–16 kbar at 600–680 °C (Fig. 4; Medaris et al., 1995).The peak metamorphism of the volcano-sedimentaryrock series in the Lugian domain varies from garnetto kyanite grade, yielding 7)9 kbar at 550)650 °C(Romanova´ & Sˇtı´ pska´ , 2001; Jastrzębski, 2005;Murtezi, 2006) with re-equilibration in the sillimanitestability field at sub-solidus conditions of 5–6 kbar ataround 600 °C.In the Monotonous and Varied Groups of theMoldanubian domain, scarce U)Pb zircon data fromorthogneisses and metavolcanic rocks yield Neoproterozoicand Cambrian protolith ages (Fig. 3c;Schulmann et al., 2005). U)Pb zircon data frommetavolcanic rocks and granites of the Lugian domainÓ 2007 Blackwell Publishing Ltd138