Appendix 1: Analytical techniques
Whole-rock geochemistry
Most of the major-element whole-rock analyses were performed in the laboratories of the Czech Geological Survey, Prague-Barrandov. The following methods were applied (in brackets are detection limits, wt. %) – flame atomic absorption spectroscopy, FAAS: TiO2 (0.01), Al2O3 (0.01), Fe2O3 (0.01), MnO (0.001), MgO (0.01), CaO (0.01), Na2O (0.01), K2O (0.01), and Li2O (0.001); titration: SiO2 (0.1) and FeO (0.03); ICP-OES: BaO and SrO (0.005); colorimetry: CO2 (0.05); photomultiplier tube (PMT): P2O5 (0.005); ion selective electrodes: F (0.005). 
All trace-element and several major-element analyses were carried out in the Activation Laboratories, Ancaster, Canada (http://www.actlabs.com). Samples were mixed with a flux composed of lithium metaborate and lithium tetraborate and fused in an induction furnace. The melt was poured into a solution of 5% nitric acid containing an internal standard, and mixed continuously until completely dissolved. The samples were run for major oxides and selected trace elements (Sr, Ba and V) using a combination of simultaneous/sequential Thermo Jarrell-Ash ENVIRO II and Spectro Ciros ICP-OES. Further trace elements were determined using two Perkin Elmer SCIEX ELAN 6000 and 6100 ICP-MS. 
Sensitive High Resolution Ion Microprobe (SHRIMP-RG) U–Pb zircon dating
Samples from the Blatná and Kozárovice granodiorite were collected at two working quarries (Bl-2: Tužice; Koz-26: S of the village of Kozárovice) for in situ zircon analysis by ion probe technique. At least 10 kg of fresh rock material from each sample was crushed and zircons were concentrated by combined heavy liquid (methylene iodide) and magnetic separation at the Czech Geological Survey in Prague-Barrandov. The zircon concentrates were finally handpicked for final purity. U-Th-Pb analyses were conducted using SHRIMP-RG (reverse geometry) ion microprobe in the SUMAC facility at Stanford University, USA. Zircons were mounted on double stick tape, cast in epoxy in a 25 mm diameter by 4 mm thick disc, and ground and polished to 1-micron finish . All grains were imaged with reflected light on a petrographic microscope, and with cathodoluminescence on a JEOL 5600 SEM to identify internal structures, inclusions and physical defects. The mounted grains were washed with EDTA solution, distilled water, dried in a vacuum oven, and Au coated. Measurements for U-Th-Pb ratios were conducted with an O2- primary beam, varying between 4 and 6 nA. The analytical crater had a size of 20–40 microns in diameter and a depth of 1–2 microns. The number of scans through the measured mass sequence and counting times on each peak were varied according to sample age and U and Th concentrations to improve counting statistics and age precision. Measurements were made at mass resolutions of 6000–8000, which eliminates all interfering atomic species. Concentration data for zircons were standardized against the 564 Ma old Sri Lanka zircon standard CZ3 (550 ppm U) (Pidgeon et al. 1994; Nelson 1997), and age data against the zircon standard R33 (419 Ma from monzodiorite, Braintree Complex, Vermont; Black et al. 2004). Raw data reduction and age calculations were processed with the computer programs Squid and Isoplot (Ludwig 2002, 2003) using the decay constants recommended by the IUGS (Steiger & Jäger 1977).
References
Black L. P., Kamo S. L., Allen C. M., Davis D. W., Aleinikoff J. N., Valley J. W., Mundil R., Campbell I. H., Korsch R. J., Williams I. S. & Foudoulis C. 2004. Improved 206Pb/238U microprobe geochronology by the monitoring of a trace-element-related matrix effect: SHRIMP, ID-TIMS, ELA-ICP-MS and oxygen isotope documentation for a series of zircon standards. Chemical Geology, 205, 115–140.
Ludwig, K. R., 2002. SQUID 1.02, A User’s Manual. Berkeley Geochronology Center Special Publications, 2, 2455 Ridge Road, Berkeley, CA 94709, USA.
Ludwig, K. R., 2003. ISOPLOT 3.0, A Geochronological Toolkit for Microsoft Excel. Berkeley Geochronology Center Special Publications, 4, 2455 Ridge Road, Berkeley, CA 94709, USA.
Nelson, D. R., 1997. Compilation of SHRIMP U–Pb zircon geochronology data, 1996. Geological Survey of Western Australia, Rec. 1997/2.
Pidgeon, R. T., Furfaro, D., Kennedy, A. K., Nemchin, A. A. & van Bronswjk, W. 1994. Calibration of zircon standards for the Curtin SHRIMP II. In: Eighth International Conference on Geochronology, Cosmochronology and Isotope Geology (Berkeley); Abstract volume. U.S. Geological Survey Circulars, 1107, 251.
Steiger, R. H. & Jäger, E. 1977. Subcommission on geochronology: convention on the use of decay constants in geo- and cosmochronology. Earth and Planetary Science Letters, 36, 359–362.