TY - JOUR A1 - Zacek,V. T1 - Retrograded eclogite from the Stare Mesto Belt, NE margin of the Bohemian Massif JF - Journal of the Czech Geological Society JA - J. Czech Geol. Soc. Y1 - 1996 VL - 41 IS - 3-4 SP - 167 EP - 175 CY - Prague PB - Czech Geological Society SN - 1803-1943 (online), 1802-6222 (print) AV - Free UR - http://www.jgeosci.org/index.php?pg=detail&ID=JCGS.716 L1 - http://www.jgeosci.org/content/Zacek_et_al_1996.pdf KW - eclogite KW - mineral chemistry KW - P-T conditions KW - retrogression KW - Stare Mesto Belt KW - West Sudetes KW - Variscides AB - Strongly retrograded eclogite was found at the NE edge of the Stare Mesto Belt most probably representing a suture zone, in the eastern rim the Orlice-Klodsko Unit. While primary garnet is preserved, (Alm 51-59, Grs 17-31, Pyr 13-17, Sps 1.3-2.1), clinopyroxene I is completely replaced by clinopyroxene II (Jd 18) - plagioclase I (An 10-14) symplectite. Continuing retrogression led to growth of hornblende + plagioclase II (An 17-42) at the expense of symplectite. Amphibolite sampled nearby displays a prograde zoning of garnet in the range of amphibolite facies, (Alm 56-62, Grs 24-30, Pyr 5-10 Sps 0.4-10); the assemblage includes hornblende, plagioclase (An 12-31), quartz and biotite. Thermobarometry indicates that local equilibrium of rocks of different previous P-T histories has been attained at conditions of high amphibolite facies at 650-725-C and 8-11 Kb. The highest pressure record of 11.5-12.5 Kb at 600-680-C, indicating conditions transitional between eclogite and amphibolite facies, yielded the sample of retrograded eclogite with preserved symplectite. The partial P-T path of retrograded eclogite shows a moderate uplift between 40-30 km and a re-equilibration at depth of about 30 km. ER -