Nalazite se na CroRIS probnoj okolini. Ovdje evidentirani podaci neće biti pohranjeni u Informacijskom sustavu znanosti RH. Ako je ovo greška, CroRIS produkcijskoj okolini moguće je pristupi putem poveznice www.croris.hr
izvor podataka: crosbi !

New pieces to the Croatian part of Tisia jigsaw puzzle: role of age dating, geothermobarometry and accessory minerals in transforming of “ simple” insight into a future complex model (CROSBI ID 508973)

Prilog sa skupa u zborniku | sažetak izlaganja sa skupa | domaća recenzija

Balen, Dražen New pieces to the Croatian part of Tisia jigsaw puzzle: role of age dating, geothermobarometry and accessory minerals in transforming of “ simple” insight into a future complex model // Abstracts Book / Velić, Ivo ; Vlahović, Igor ; Biondić, Ranko (ur.). Zagreb: Hrvatski geološki institut, 2005. str. 7-8-x

Podaci o odgovornosti

Balen, Dražen

engleski

New pieces to the Croatian part of Tisia jigsaw puzzle: role of age dating, geothermobarometry and accessory minerals in transforming of “ simple” insight into a future complex model

Several current research projects (see at the bottom) dealing with the still enigmatic Tisia are focused to age distinction of different, and not in detail studied, metamorphic and magmatic events, which broadly occurred during pre-Variscan, Variscan and Alpine orogeny. At the moment, available data collected all over the Tisia (not only in Croatia) are too scarce to be used for reliable geodynamic interpretation of the particular metamorphic and/or igneous event(s). Therefore, the aim of present work in the area is confronted with the challenge to separate different stages of metamorphism/magmatism and to derive PT data together with metamorphic isogrades for different events separately. Igneous, mainly granitic, rocks together with metamorphic rocks outcropping in the Moslavačka Gora area and the Slavonian Mts. area represent an important crystalline lithology which provide geological information through their mineralogical, geochemical and isotopic signatures with special focus to the accessory minerals (monazite, zircon, &#8230; ) as important recorders of evolution. Moslavačka Gora area Recent age dating in the Moslavačka Gora area applying Ar-Ar, Rb-Sr and Sm-Nd methods provided, as a rule, Cretaceous ages (BALEN et al., 2001 ; 2003). First data provided by microprobe monazite geochronology gave also Cretaceous crystallization age for Pleterac granite 74 &plusmn ; 17 Ma, and Cretaceous metamorphism (93 &plusmn ; 12 Ma) for cordierite-garnet-K-feldspar metapelite from Kamenjača Stelovača. However, metapelite with andalusite from Jaska potok show two ages: Permian 269 &plusmn ; 24 Ma (relict monazite) and Cretaceous 116 &plusmn ; 31 Ma (newly grown monazite). STARIJAŠ et al. (2004) distinguished two different groups of Cretaceous age fine-grained biotite-granites (biotite contents 4-10 vol.%), i.e. the Pleterac type (PT) and the Garić-grad type (GGT). The PT granites are mostly undeformed, chemically correspond to peraluminous S-type granite and comprise muscovite (2-4 vol. %). GGT granites often show a slight foliation and their chemistry point to igneous lower crustal sources. The differences between two granite groups are also shown in zircon typology. The PT granites show unusual zircon morphology patterns with two maxima, one in the right upper corner of the Pupin diagram, where {;101}; is combined with {;110}; i.e. I-type morphology, the other one showing steep {;211}; pyramides combined with the {;110}; prism. Such bimodal patterns may be indicative for felsic I-type granite melts that were chemically modified and driven towards S-type compositions through assimilation of meta-sedimentary material. The GGT granites have zircons with large {;100}; prisms and a dominant {;101}; pyramide, in accordance with their chemical I-type signatures. In summary, zircon typology of Moslavačka Gora introduces three clusters which indicate (1) the presence of at least two groups of granitoids in the crystalline core of Moslavačka Gora, and (2) mixing of mantle/lower crust material with a crustal material. Those conclusions are supported also with trace element geochemistry (for further details see STARIJAŠ et al., this volume). The age results combined with PT data which point to high-temperature metamorphism (up to amphibolite/granulite facies transition) put a question mark on geodynamic evolution of Moslavačka Gora as a part of Tisia and push it more likely toward a Cretaceous high-heat-flow belt. Slavonian Mts. area Microprobe monazite geochronology in the Slavonian area show rather unexpected results. In the Psunj (Kutjevo) metamorphic complex Th, U, Pb contents of yttrium-rich accessory monazites indicate a pre-Variscan, i.e. Silurian (428&plusmn ; 25 and 444&plusmn ; 19 Ma) age for the medium-grade metamorphism of garnet-bearing micaschists exposed along the Kutjevačka Rijeka transect. Furthermore, andalusite and staurolite bearing micaschists from &#8220; Krndija quarry&#8221; (near village Gradište) comprise mainly Variscan monazite (broadly 350 Ma), and two monazite grains showed a Permian age. Since for Krndija quarry these are preliminary data, the significance of the latter remains unclear: either it is a true crystallization age indicative of a Permian thermal event or the age is the result of Pb loss. In the Papuk (Jankovac) metamorphic complex igneous rocks represented by Šandrovac granite yielded 340 &plusmn ; 15 Ma. Thermobarometric calculations were performed on the peak assemblages of micashist, gneiss and amphibolite from Kutjevačka Rijeka transect. The micaschist THERMOCALC calculations yielded 600-630 °C and 9-11 kbar while gneiss yielded 600-630 °C and 6.5-7.5 kbar. Additionally, results for Grt+Hbl+Pl assemblage of gneiss are 500-580 °C and 8-10 kbar, 640°C (Hbl+Pl) and 650 °C (Grt+Bt). In the amphibolites calculated T values range between 590 and 620 °C for edenite-richterite and edenite-tremolite reactions, respectively. In addition, Grt+Hbl thermometry yielded 490-570 °C, while using Grt+Hbl+Pl barometry we obtained 7-10 kbar. Preliminary calculation for micaschist from &#8220; Krndija quarry&#8221; gives 520-570 °C and low pressures of 3-4 kbar (Horváth, pers. comm.) Radlovac metamorphic complex is recently a subject of intensive study of illite (IC) and chlorite (ChC) &#8220; crystallinity&#8221; (see BIŠEVAC et al., this volume). Illite and chlorite "crystallinity" indices, obtained on the <2&#956; m fractions, show that thermal alterations (regional metamorphism) range from the upper anchizone (approximately 250°C) to the low temperature part of epizone (300°C). The results of vitrinite reflectance measurements show good correlation with IC and ChC data. The presented petrological and PT data together with additional microstructural, paragenetic, mineral chemistry and age data from Croatian part of Tisia can not be directly correlated with results obtained in the nearby parts of the Tisia in Hungary, and clearly show to us that Tisia puzzle is certainly far from being solved. Presentation is result of research referred to recent project leading and/or participating by author: - MZOŠ RH project no. 0119412: Crystalline complexes of Sava-Drava interfluve (coworkers: Mirko Belak, Vanja Biševac, Darko Tibljaš, Darko Španić) - HAS & HAZU: Comparative metamorphic petrogenetic study of the complexes in the southern part of the Tisia Unit, as well as the Internal Dinarides and the Bükk Unit and their relative position during metamorphism (Péter Árkai, Péter Horváth, Katalin Judik, Darko Tibljaš, Bruno Tomljenović) - Austria-Croatia bilateral scientific project: Correlation of Variscan crust in Austria and Croatia: Variscan evolution of the southern part of the Tisia unit (Croatia) with special reference to the time relation of igneous and metamorphic rocks (Friedrich Finger, Bernhard Humer, Biljana Starijaš, Gudrun Riegler) ; - Informal cooperation with Vesnica Garašić, Marija Horvat and Ralf Schuster. References BALEN, D., SCHUSTER, R., GARAŠIĆ, V. (2001): A new contribution to the geochronology of Mt. Moslavačka Gora (Croatia).- PANCARDI 2001Abstracts, DP-2, Sopron. BALEN, D., SCHUSTER, R., GARAŠIĆ, V., MAJER, V. (2003): The Kamenjača olivine gabbro from Moslavačka Gora (South Tisia, Croatia).- Rad HAZU, 486, 27, 57-76. STARIJAŠ, B., BALEN, D., TIBLJAŠ, D., SCHUSTER, R., HUMER, B., FINGER, F. (2004): The Moslavačka Gora Massif in Croatia: part of a Late Cretaceous high-heat-flow zone in the Alpine-Balkan-Carpathian-Dinaride collision belt.- Ber. Inst. Erdwiss. K.-F.-Univ. Graz, 9, 453-454, Graz.

age dating; geothermobarometry; zircon; monazite; Tisia; Croatia

nije evidentirano

nije evidentirano

nije evidentirano

nije evidentirano

nije evidentirano

nije evidentirano

Podaci o prilogu

7-8-x.

2005.

nije evidentirano

objavljeno

Podaci o matičnoj publikaciji

Abstracts Book

Velić, Ivo ; Vlahović, Igor ; Biondić, Ranko

Zagreb: Hrvatski geološki institut

Podaci o skupu

3. hrvatski geološki kongres

predavanje

29.09.2005-01.10.2005

Opatija, Hrvatska

Povezanost rada

Geologija