ACTA MUSEI MORAVIAE - SCIENTIAE GEOLOGICAE 91/2006
Houzar, S., Novák, M., Doležalová, H., Hrazdil, V., Pfeiferová, A., 2006: Přehled mineralogie, petrografie a geologie nedvědických mramorů, svratecké krystalinikum. Acta Musei Moraviae, Sci. geol., 91, 3–77.
Mineralogy, petrography and geology of the Nedvědice marbles, Svratka Crystalline Complex; a review
Nedvědice marbles occur in a narrow belt situated along the eastern and northeastern margin of the Svratka Crystalline Complex (Moldanubian Zone). Elongated bodies of calcite marbles up to 150 m long and 40 m thick, with abundant boudins of various calc-silicate rocks, are enclosed in muscovite-biotite paragneisses. The following types of marbles were distinguished: a) silicates-poor marbles with the assemblage: Cal + Phl + Tr ± Di ± Dol ± Gr; b) silicates-enriched skarnized marbles (sky blue Cal + Ves + Wo ± Grs ± Di ± Czo) and c) rare pale red marbles (Cal + Bt + Ms + Ep ± Di ± Qtz ± Kfs). Calc-silicate rocks include diopside gneiss and diffusive reaction skarns (Di + Qtz + Kfs + Czo + Pl + Ttn ± Amf ± Grs) and a variety of hornfelses, skarnoids and skarns with the mineral assemblage – Di + Grs + Ves + Wo ± Kfs. The mineral assemblages given above are products of complex metamorphic evolution. (I) The early stage – isochemical regional metamorphism of amphibolite facies – is characterized by the relic equilibrium assemblage Dol + Tr. (II) Next stage is related to intrusion of peraluminous granites into host metapelite complex. Associated fluids rich in H2O, F and locally also B, K and Na reacted with marbles and intercalations of diopside gneiss and hornfels (T > 550°C at P = 200 MPa, XCO2 < 0.2–0.1) and produced skarnoids and skarns with the assemblages involving vesuvianite, grossular, diopside and wollastonite, as dominant minerals, and minor to accessory K-feldspar, clinozoisite, fluorite and Fe–Cu–Sn–As–Sb–Bi mineralization. (III) postskarns with ferroaxinite, tourmaline and part of K-feldspar and late vesuvianite, locally filling fissures. (IV) Subsequent metamorphism is related to ductile deformation of marbles at low temperature (T > 450°C for 200 MPa or eventually > 650°C for 500 MPa) along the zone about 50 km long but only several tens m thick. Formation of sky blue calcite and equilibrium assemblage Ves + Wo specific for the Nedvědice marbles at high activity of H2O (XCO2 > 0.05) is related to this process as well. Source of external H2O-rich fluids is not clear but it seems to be related to the Variscan nappe development. (V) This retrograde stage involves namely formation of pectolite on fissures. The Nedvědice marbles differ from other marbles of the Svratka Crystalline Complex in dissimilar geological position in the outermost part of the unit, low MgO and SiO2 contents, and by the assemblage – sky blue Cal + Ves + Wo. The mineral assemblage of Nedvědice marbles with sky blue calcite, abundant vesuvianite and wollastonite, accessory malayaite, zircon and native Bi is unique in the Bohemian Massif as well as regional distribution of the equilibrium assemblage Wo + Ves in ductile domains in marbles located in the narrow belt about 50 km long. Key words: calcite marble, blue marble, calc-silicate rocks, skarn, chemical composition, mineral assemblage, metamorphism, regional geology, historical use of marble, Nedvědice area, Svratka Crystalline Complex, Moravia, Czech Republic.
Cempírek J., Novák M., 2006: Hydroxylherderit a sdružené berylofosfáty z pegmatitu Rožná-Borovina. Acta Mus. Moraviae, Sci. Geol., 91, 79–88.
Hydroxylherderite and associated beryllophosphates from pegmatite Rožná-Borovina
In lepidolite pegmatite Rožná, hydroxylherderite was known since 1950 in pseudomorphs after unknown mineral of pseudocubic shape and the original mineral remained unknown up to now. New samples available for this study confirmed rather monoclinic symmetry. Recent study of this material (powder X-ray diffraction, electron microprobe, cathodoluminiscence) revealed that several beryllium minerals occur within pseudomorphs in two distinct assemblages involving hydroxylherderite as a dominant mineral. The assemblage I consists of beryllonite + hurlbutite + hydroxylherderite + fluorapatite, whereas assemblage II contains bertrandite + quartz + hydroxylherderite + fluorapatite. In both assemblages, small inclusions of unknown Ba- or Sr-phosphates occur; stoichiometrically they best correspond to Ba- and Sr- equivalents of hurlbutite. Beryllonite was very likely the primary mineral of pseudomorphs with the assemblage I, whereas in the case of the assemblage II the primary mineral might be beryllonite or beryl. The herderite pseudomorphs from Rožná are a good example of complicated polyphase replacement of Be-dominant primary mineral (beryllonite and/or beryl) in highly variable activities of Ca, P, F and Si, producing various beryllophosphates versus Be-silicates.
Key words: lepidolite pegmatite, beryllophosphates, beryllium, Moldanubicum, Czech Republic.
Jan Cempírek, Moravské zemské muzeum, Mineralogicko-petrografické oddělení, Zelný trh 6, 659 37 Brno. E-mail: email@example.com
Milan Novák, Ústav geologických věd, Masarykova Univerzita, Kotlářská 2, 611 37 Brno
Pauliš, P., Škoda R., Novák, F., 2006: Demesmaekerit z uranového ložiska Zálesí v Rychlebských horách. – Acta Mus. Moraviae, Sci. Geol., 91, 89–95.
Demesmaekerite from uranium deposit Zálesí in the Rychlebské hory Mts. (Czech Republic)
A rare secondary mineral demesmaekerite Pb2Cu5(SeO3)6(UO2)2(OH)6 . 2H2O was newly found on the old dumps of Pavel vein at the abandoned uranium deposit of Zálesí in Rychlebské hory Mts. Demesmaekerite forms light green compact aggregates up to 1 mm large, in cavities also tabular crystals with vitreous lustre, up to 0.05 mm in size. It commonly forms intergrowths with deep blue chalcomenite. The XRD data of demesmaekerite together with the chemical composition of demesmaekerite and chalcomenite are given. Both minerals represent the decomposition product of clausthalite, uraninite and chalkopyrite. Demesmaekerite is very rare secondary mineral and Zálesí represents its second world occurrence.
Key words: demesmaekerite, uranium deposit, Zálesí, Czech Republic
Petr Pauliš, Smíškova 564, 284 01 Kutná Hora, Czech Republic, E-mail: firstname.lastname@example.org
Radek Škoda, Ústav geologických věd, PřF MU, Kotlářská 2, 611 37 Brno, Czech Republic, E-mail: email@example.com
František Novák, Dolní 265, 284 01 Kutná Hora, Czech Republic.
Dokoupilová, P., Losos, Z., Vávra, V. 2006: Sekundární mineralizace na haldě dolu Kukla v Oslavanech. Acta Mus. Moraviae, Sci. geol., XXII: 97–104.
Secondary mineralization on the mine waste of the Kukla coal mine in Oslavany
Secondary minerals on the waste tip of the Kukla coal mine in Oslavany are described. In the 2005, sulphur, gypsum and hexahydrite were collected and verified. New phases for the locality are secondary anhydrite, aragonite, hematite, calcite, konyaite and spinels. Massive hematite and spinels formed at high temperature during the burning of the mine waste. Other secondary minerals are younger and according to climatic condition repetualy recrystallize on the surface of the coal dump.
Key words: burning coal mine waste, secondary minerals, hematite, sulphates
Pavla Dokoupilová, Institute of Geological Sciences, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic; e-mail: PavlaDokoupil@seznam.cz
Zdeněk Losos, Institute of Geological Sciences, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic; e-mail: firstname.lastname@example.org
Václav Vávra, Institute of Geological Sciences, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic; e-mail: email@example.com
Čopjaková, R., Škoda, R., 2006: Detritické a autigenní REE minerály v sedimentech kulmu Drahanské vrchoviny, jejich význam pro studium provenience klastického materiálu a procesů diagenese. Acta Musei Moraviae, Sci. Geol., 91: 105–127.
Detrital and authigennic REE minerals from Culm sediments of Drahany Uplands, their significance for provenance study of clastic material and diagenetic processes.
Electron microprobe study of mineral chemistry, chemical age and alteration of detrital monazite as well as composition and textural position of authigenic REE minerals – rhabdophane-(Ce), synchysite-(Ce) and thorogummite – have been carried out on the samples of clastic Culm sediments from the Drahany Uplands. Detrital monazite is commonly homogeneous in BSE, only it exceptionally shows an irregular zoning. Some monazite grains are replaced by apatite and hydrated REE-minerals propagating from rim inwards and along fractures. Three different stages of detrital monazite alteration were observed: the first stage is characterized by minor depletion of heavy REE (Gd, Dy, Er), Y, Th and Pb, but it does not show any significant deviations in the ideal stochiometry. The second stage is accompanied by strong depletion of Gd, Dy, Er, Y, Th, U and Pb, the stochiometry is disrupted and totals decrease up to 98–96 wt. % of oxides. The last stage is characterized by depletion of light REE (La, Ce) and all above mentioned elements. Grade of alteration positively correlates with intensity of diagenesis from the Myslejovice to the Protivanov Formation. Unaltered detrital monazite from all stratigraphic units and monazite from pebbles in the Račice conglomerates were used for U–Th–Pb electron microprobe dating. Majority of detrital monazite from Protivanov, Rozstání and lower part of Myslejovice Formation displays Viséan age (339 ± 15, 331 ± 19 and 335 ± 14 Ma, respectively). Monazite from clasts of mica-schist, orthogneiss and aplite yield similar ages: 330 ± 21 Ma, 332 ± 22 Ma and 331 ± 17 Ma, respectively. Three small grains of monazite gave late Devonian age 373 ± 49 Ma. One detrital monazite from lower part of Myslejovice Formation yielded Precambrian age 603 ± 65 Ma, which is similar to the Moravo-Silesian Zone (Brno Batholith or orthogneisses protholite). Monazite dating does not support beginning of sedimentation at the border Tournai/Viséan and diachronous deposition of the flysch formations. It also suggests similar stratigraphic range of the Protivanov, Rozstání and Lower part of Myslejovice Formation. Common authigennic minerals – rhabdophane-(Ce), thorogummite and OH analogue of synchysite-(Ce) show similar chemical composition despite they occur either as replacement of monazites or crystallize in the matrix.
Key words: REE minerals; monazite dating; alteration; diagenetic fluids; Lower Carboniferous Culm basin; provenance; Bohemian Massif
Škoda, R. Novák, M., Houzar, S. 2006: Granitické NYF pegmatity třebíčského plutonu. Acta Mus. Moraviae, Sci. Geol., 91, 129–176.
Granitic NYF pegmatites of the Třebíč Pluton (Czech Republic)
Homogeneous segregations to complexly zoned dikes of granitic pegmatites, up to 2 m thick, are enclosed in Hercynian (ca. 340 Ma), I-type, ultrapotassic, porphyric, amphibol-biotite melasyenite to melagranite (durbachite) of the Třebíč Pluton (TP), Moldanubicum, western Moravia, Czech Republic. They typically show transitional contacts with the host syenites to granites. Mineral composition the pegmatites is characterized by dominance of K-feldspar (locally amazonite) over albite, common Mg-rich biotite (phlogopite) but absence of primary muscovite, common Y, REE-bearing minerals (allanite-(Ce), aeschynite and euxenite group minerals) and Ti-bearing minerals (titanite I, ilmenite). Further common accessory minerals include actinolite, zircon, monazite-(Ce), beryl, phenacite and niobian rutile. Tourmaline (abundant Ca, Ti, Fe3+-rich dravite to schorl, very rare Al-rich schorl) is a typical minor to accessory mineral in some euxenite pegmatites but rather rare in allanite pegmatites. Abundant alteration products include chlorite, pyrochlore group minerals, bastnäsite-(Ce), pseudorutile and titanite II. Specific zinnwaldite–masutomilite–elbaite pegmatite from Kracovice cuts gneiss nearby the western border of the TP. It exhibits similar mineralogical features – common Y, REE-bearing minerals (samarskite group minerals, fergusonite, monazite-(Ce), xenotime-(Y), yttropyrochlore, Y-rich spessartine), presence of amazonite but it also contains primary muscovite and abundant Li, B, Be, Mn, F-rich minerals such as zinnwaldite, masutomilite, Mn-rich lepidolite, elbaite, topaz, spessartine, beryl and hambergite. The examined pegmatites are classified as typical metaluminous, NYF pegmatites of the allanite and euxenite subtype; however, peraluminous, Li, Mn, F, B-rich pegmatite from Kracovice may also belong to the „Mixed“-family. Geochemical evolution from Mg-rich, metaluminous allanite subtype pegmatites, through less evolved euxenite subtype pegmatites and more evolved Mn, F, B-enriched albitized euxenite pegmatite from Klučov to highly evolved peraluminous Li, Mn, F, B-rich pegmatite from Kracovice is characterized by significant increase in activity of Li, F, Mn, Sn, Y, HREE and Nb, but depletion in Ca, Mg, LREE and Ti. Enrichment in B and Be during fractionation is less apparent. Granitic NYF pegmatites related to other durbachite bodies of the Bohemian Massif (Čertovo břemeno, Drahonín) show similar geochemical and mineralogical features, but they are generally slightly more evolved and they were classified as gadolinite subtype absent within the TP. Euxenite subtype pegmatites from Trout Creek Pass, Colorado, USA are similar to those from TP.
Key words: mineralogy, granitic pegmatites, NYF family, REE minerals, Třebíč Pluton, Bohemian Massif, Czech Republic.
Radek Škoda, Milan Novák, Institute of Geological Sciences, Masaryk University, Kotlářská 2, 611 37 Brno, e-mail: firstname.lastname@example.org
Stanislav Houzar, Department of Mineralogy and Petrography, Moravian Museum, Zelný trh 6, 659 37 Brno, Czech Republic, e-mail: email@example.com
Dosbaba, M., Sulovský, P. 2006: Geological position, petrology and geochemistry of durbachite bodies in the vicinity of Nové Město na Moravě. – Acta Mus. Morav., Sci. geol., 91, 177–190 (with English abstract).
Geological position, petrology and geochemistry of durbachite bodies in the vicinity of Nové Město na Moravě
Three bodies of ultrapotassic rocks (durbachites) crop out in the vicinity of Nové Město na Moravě. The western most body dips to the NW, while the orientation of other bodies is not clear. Geologic position is comparable with Třebíč pluton. The chemistry of these rocks can be explained by simple magma mixing proposed by HOLUB (1997). One of the bodies is unlike the others peraluminious, which is caused by assimilation of surrounding metamorphic rocks. Fractional crystallization of mafic minerals (hornblende) is also probable. Crystallization conditions were estimated on the basis of hornblend – plagioclase thermometer, zircon saturation temperature and equilibrium pairs of amphibol and biotite. The inferred temperatures ranged between 700–830 °C. Water contents in the magma could reache up to 8 wt. %. All of the bodies underwent subsolidus deformation in the temperature range 300–400 °C resulting in the occurrence of slip cleavage dipping to the NW at. ca. 30° (sinistral strike slip in a NW–SE direction) which could be attributed to the gravitational collapse of Variscan orogeny in the Lower Carboniferous.
Key words: durbachite series, petrology, geochemistry, Strážek, moldanubicum, PT conditions
Marek Dosbaba, Petr Sulovský, Institute of Geological Sciences, Masaryk University Brno, Kotlářská 2, Brno, 637 11, Czech Republic, firstname.lastname@example.org
Buriánek, D., 2006: Vápenatosilikátové horniny v poličském krystaliniku – Acta Musei Moraviae, Sci.geol., 91: 191–206.
Calc-silicate rocks from Polička crystalline Complex
Two distinct types of calc-silicate rock occur in the Polička Crystalline Complex. The biotite and two-mica gneisses with nodules calc-silicate rocks are typical members of a monotonous zone Polička Crystalline Complex. Elongated bodies of calc-silicate rock are situated in the varied zone along boundary between Polička Crystalline Complex and Svratka Crystalline Complex. They are associated with amphibolites, marbles and gneisses. The mineral assemblage is similar in both groups (nodules calc-silicate rocks: Qtz + Pl + Di + Ttn ± Czo ± Amp ± Grt ± Cal and bodies of calc-silicate rock: Qtz + Pl + Di + Ttn ± Kfs ± Scp ± Ep (Czo) ± Amp ± Grt ± Cal ± Chl). Mineral equilibria in calc-silicate rocks and surrounding metapelites provide estimates of metamorphic PT conditions for both groups 570–680 °C and 5–7 kbar. The garnet is typical constituent for nodules calc-silicate rocks on the major part Polička Crystalline Complex. However in the bodies of calc-silicate rock garnet is present only on the SE margin Polička Crystalline Complex. The spatial distribution of garnets depends on the chemical composition rocks and fluids during metamorphic evolution. Fluid compositions supposed for the nodules calc-silicate rocks are systematically lower in XCO2 than those from bodies of calc-silicate rock. Chemical and mineralogical work leads to the conclusion that they resulted from regional metamorphism under amphibolite facies conditions. The occurrence of actinolite, chlorite and clinozoisite resulted from later retrograde metamorphism.
Key words: calc-silicate rocks, Polička Crystalline Complex, PT conditions, Czech Republic,
David Buriánek, Czech Geological Survey, Leitnerova 22, 658 59, Brno, Czech Republic; email@example.com
Hrazdil, V., Vokáč, M., Houzar, S., Dočkal, P., 2006: Vltavínonosné sedimenty v okolí Lukova u Moravských Budějovic, západní Morava. – Acta Musei Moraviae, Sci. geol., 91: 207–217.
Moldavite-bearing sediments near Lukov in the vicinity of Moravské Budějovice, Western Moravia
Between 1998–2005 several moldavites have been collected in two new localities near Lukov. They are olive-green in colour and have angular to subangular shape with lustrous and mat surface. The chemical composition of one sample shows similarity to the average Moravian moldavites (mainly Ca/Ti ratio), but Si and Ti content are consistent with Bohemian moldavites. Sporadic lechatelierite is the only inclusion. The source of moldavites near Lukov is Middle-Upper Miocene deluvio-fluvial clay and/or sand dominated sediments with gravel admixture (so-called strewn-field sediments). The sediments are poorly sorted and contain mainly subangular quartz and quartzite transported over relatively short distances, but well rounded pebbles redeposited from older sediments are also present. During younger transformation, especially in Quaternary age, primary fine-grained strewn-field sediment with short transported moldavites passes into residual gravels. Brown fragments of ferrolite abundantly occur in both localities. Typical opaque mineral in these sediments is maghemite (brown, magnetic granules and pebbles). Assemblage of heavy minerals (ilmenite, rutile, garnet, sillimanite, spinel) is similar to the underlying gneiss, and its older sedimentary cover (andalusite, kyanite). These sediments could be locally redeposited by fluvial transport of previous Rokytka stream and finally covered by loess.
Key words: new moldavite occurrences, strewn-field sediment, gravel, chemical composition, Lukov area, Moravia, Czech Republic.
Vladimír Hrazdil, Stanislav Houzar, Petr Dočkal, Department of Mineralogy and Petrography, Moravian Museum, Zelný trh 6, 659 37 Brno, Czech Republic. E-mail: firstname.lastname@example.org
Milan Vokáč, Department of Archeology, Muzeum Vysočiny, Masarykovo nám. 55, 586 01 Jihlava, Czech Republic. E-mail: email@example.com
Lisá, L., Zapletalová, D., Pecka, M., Zůbek, A.,Mroczek, P. (2006): Kvartérní geologická stavba historického jádra města Brna: aplikace poznatků ze stavby kolektorů. Acta Musei Moraviae, Sci. geol., 91, 219–226.
Quaternary Geological Composition of Brno Historic Centre: Application of Results from the Collector Canalization
The collector channels building exposed unique sections documenting the geology of the historic Brno centre. The sequence of loess and loess-like sediments interrupted by doubled paleosols and colluvial sediments, and influenced by post-depositional processes, lies on the undulating Neogene sediments (Tegel). Sedimentation was completed by Holocene soil, which can be in some cases interpreted as fillings of little dells. Very common is the interference with sediments of the Ponávka River lying on the Neogene sediments. Fluvial pebles of this river, together with other typical fluvial sediments such as flood-plain sediments, blocks of Neogene sediments fallen into the river, or loess and soils redeposited by water, were encountered in the collectors. All sections are strongly affected by anthropogeneous activity.
Key words: collector channels, sedimentology, micromorphology, Quaternary
Lenka Lisá, Institute of Geology, Academy of Sciences CR, Rozvojová 269, 165 02, Prague, Czech Republic; firstname.lastname@example.org
Dana Zapletalová, Marek Pecka, Antonín Zůbek, Archaia o.p.s., suboffice Brno, Česká 156/6, 602 00, Brno, Czech Republic; email@example.com
Przemyslaw Mroczek, Earth Sciences Institute, Maria Curie-Sklodowska University, ul. Krasnicka 2cd, 20-718 Lublin, Poland, firstname.lastname@example.org
Ábelová, M. (2006): Analýza mikroštruktúr klov druhu Mammuthus primigenius (Blumenbach, 1803) Acta Musei Moraviae, Sci. geol., 91, 227.233.
Microstructure analysis of Mammuthus primigenius (Blumenbach, 1803) tusks
Twenty seven samples of fossil Mammuthus primigenius tusks from four Upper-palaeolithic Moravian
localities (27 000-22 000 BP) [Napajedla (Gravettian), P.edmosti (Gravettian), Dolní Věstonice
(Gravettian) and Milovice (Gravettian)] and one Wurmian Croatian locality (Dolnij Miholjac) were
studied in regard to the microstructure analysis of the dentine part. Measurements were taken from the
Schreger angles, wavelength of undulating sets of dentinal tubules and qualitative pattern category.
We examined whether these values are changing in the scope of the tusk - from pulp cavity towards tusk
surface, how they relate to each other and whether they changed in the course of geological time.
We found out that Schreger angle reaches about 40° near the pulp cavity. The angles increase toward tusk
surface and reach maximal values about 110°.
Key words: tusk, Schreger pattern, Mammuthus primigenius, Proboscidea, Wurm, Upper Palaeolith, Moravia, Croatia
Martina Ábelová, Institute of Geological Sciences, Faculty of Science, Masaryk University, Kotlářská street 2, 611 37 Brno, email@example.com, tel.: 608 06 99 26, fax.: 5 412 11 214
Ivanov, M. (2006): Herpetofauna středního pleistocénu Mladečských jeskyní (Morava, Česká republika) a její paleoekologický význam. Acta Musei Moraviae, Sci. geol., 91, 235–252.
Middle Pleistocene herpetofauna of Mladeč Caves (Moravia, Czech Republic) and its palaeoecological significance
Herpetological assemblage of Mladeč 2 site (Mladeč Caves: Moravia, Czech Republic) is a typical example of distinctively interglacial assemblage of the last warm stage of the Holsteinian complex. Altogether 12 taxa have been reported from Mladeč 2 site: Triturus cf. cristatus, Triturus vulgaris, Rana temporaria, Bufo bufo, Anguis fragilis, Elaphe longissima, Elaphe sp., Coronella cf. austriaca, Natrix natrix, Natrix cf. tessellata, Natrix sp. a Vipera berus. Herpetological assemblage of Mladeč 2 site indicates woody-steppe environment with pond biotopes and active streams in their proximity. Temperatures were generally higher than presentday temperatures. Although high mean annual temperatures were typical for the last stage of the Holsteinian complex, no Mediterranean herpetological species have been reported from this site. The absence of extant representatives of the Mediterranean herpetofauna in Central Europe (north of the Pannonian Lowland) is apparent as early as at the beginning of the Cromerian complex.
Key words: Amphibians, squamate reptiles, assemblages, climate, palaeoecology, Middle Pleistocene.
Martin Ivanov, Institute of Geological Sciences, Faculty of Science, Masaryk University, Kotlářská 2,
611 37 Brno, Czech Republic, e-mail: firstname.lastname@example.org