TY  - JOUR
A1  - Ertl, Andreas
A1  - Giester, Gerald
A1  - Schüssler, Ulrich
A1  - Brätz, Helene
A1  - Okrusch, Martin
A1  - Tillmanns, Ekkehart
A1  - Bank, Hermann
T1  - Cu- and Mn-bearing tourmalines from Brazil and Mozambique: crystal structures, chemistry and correlations
JF  - Mineralogy and Petrology
N2  - Cu- and Mn-bearing tourmalines from Brazil and Mozambique were characterised chemically (EMPA and LA-ICP-MS) and by X-ray single-crystal structure refinement. All these samples are rich in Al, Li and F (fluor-elbaite) and contain significant amounts of CuO (up to ~1.8 wt%) and MnO (up to ~3.5 wt%). Structurally investigated samples show a pronounced positive correlation between the <Y-O> distances and the (Li + Mn\(^{2+}\) + Cu + Fe\(^{2+}\)) content (apfu) at this site with R\(^2\) = 0.90. An excellent negative correlation exists between the <Y-O> distances and the Al\(_2\)O\(_3\) content (R\(^2\) = 0.94). The samples at each locality generally show a strong negative correlation between the X-site vacancies and the (MnO + FeO) content. The Mn content in these tourmalines depends on the availability of Mn, on the formation temperature, as well as on stereochemical constraints. Because of a very weak correlation between MnO and CuO we believe that the Cu content in tourmaline is essentially dependent on the availability of Cu and on stereochemical constraints.
KW  - mineralogy
KW  - Brazil
KW  - Mozambique
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-127296
VL  - 107
IS  - 2
ER  - 
TY  - JOUR
A1  - Klemd, R.
A1  - Matthes, S.
A1  - Schüssler, Ulrich
T1  - Reaction textures and fluid behaviour in very high-pressure calc-silicate rocks of the Münchberg gneiss complex, Bavaria, Germany
N2  - Calc-silicate rocks occur as elliptical bands and boudins intimately interlayered with eclogites and high-pressure gneisses in the Munchberg gneiss complex of NE Bavaria. Core assemblages of the boudins consist of grossular-rich garnet, diopside, quartz, zoisite, clinozoisite, calcite, rutile and titanite. The polygonal granoblastic texture commonly displays mineral relics and reaction textures such as postkinematic grossular-rich garnet coronas. Reactions between these mineral phases have been modelled in the CaO-Al203-Si02-C02-H2 0 system with an internally consistent thermodynamic data base. High-pressure metamorphism in the calc-silicate rocks has been estimated at a minimum pressure of 31 kbar at a temperature of 630°C with X^oSQ.Gi. Small volumes of a C02-N2-rich fluid whose composition was buffered on a local scale were present at peak-metamorphic conditions. The P-T conditions for the onset of the amphibolite facies overprint are about 10 kbar at the same temperature. A'co., of the H20-rich fluid phase is regarded to have been <0.03 during amphibolite facies conditions. These P-T estimates are interpreted as representing different stages of recrystallization during isothermal decompression. The presence of multiple generations of mineral phases and the preservation of very high-pressure relics in single thin sections preclude pervasive post-peak metamorphic fluid flow as a cause of a re-equilibration within the calc-silicates. The preservation of eclogite facies, very high-pressure relics as well as amphibolite facies reactions textures in the presence of a fluid phase is in agreement with fast, tectonically driven unroofing of these rocks.
KW  - calc-silicate rocks; fluid behaviour; P-T path; reaction textures; Variscan basement; very high-pressure metamorphism
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31035
ER  - 
TY  - CHAP
A1  - Kreuzer, H.
A1  - Henjes-Kunst, F.
A1  - Seidel, E.
A1  - Schüssler, Ulrich
A1  - Bühn, B.
T1  - Ar-Ar spectra on minerals from KTB and related medium-pressure units
N2  - No abstract available.
KW  - Kontinentales Tiefbohrprogramm
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86731
ER  - 
TY  - JOUR
A1  - Kreuzer, Hans
A1  - Seidel, Eberhard
A1  - Schüssler, Ulrich
A1  - Okrusch, Martin
A1  - Lenz, Karl-Ludwig
A1  - Raschka, Helmut
T1  - K-Ar geochronology of different tectonic units at the northeastern margin of the Bohemian Massif
N2  - No abstract available
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31811
ER  - 
TY  - CHAP
A1  - Kreuzer, Hans
A1  - Vejnar, Zdenek
A1  - Schüssler, Ulrich
A1  - Okrusch, Martin
A1  - Seidel, Eberhard
T1  - K-Ar dating in the Teplá-Domazlice zone at the western margin of the Bohemian Massif
N2  - K-Ar dating on hornblendes and micas from the Tepla Domazlice zone revealed a pattern of dates which significantly deviates from the mid-Carboniferous to early Permian one that is found in the adjacent low-pressure metamorphic Moldanubian and Saxothuringian. Especially for the Marianske Lazne metabasic complex, confirming early Czech determinations, the dates resemble the early Devonian pattern determined for the Munchberg Gneiss Massif and the Erbendorf-Vohenstrau zone of northeastern Bavaria. This supports the idea that all three units are remnants of a huge' complex which suffered a metamorphic overprint under medium-pressure conditions, probably in the early Devonian. Strong rejuvenation is found in the southern part of the Tepla-Domazlice zone by which micas and even two hornblendes were reset to mid-Carboniferous ages. According to the geological setting, part of the apparently preDevonian dates may be explained by inherited argon from earlier metamorphic and magmatic events, e.g. the high-pressure metamorphism documented in eciogitic relics. However, excess argon, caused by the mid-Carboniferous overprint cannot be excluded.
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31106
ER  - 
TY  - CHAP
A1  - Kreuzer, Hans
A1  - Vejnar, Zdenek
A1  - Schüssler, Ulrich
A1  - Okrusch, Martin
A1  - Seidel, Eberhard
T1  - K-Ar dating of the last metamorphic events in different tectonic units of the western margin of the Bohemian Massif
N2  - K-Ar dating on hornblendes and micas from the TepläDomazlice zone revealed a pattern of dates which significantly deviates from the mid-Carboniferous to early Permian one that is found in the adjacent low-pressure metamorphic Moldanubian and Saxothuringian. Especially for the Mariänske Läzne metabasic complex, confirming early Czech determinations, the dates resemble the early Devonian pattern determined for the Münchberg Gneiss Massif and the Erbendorf-Vohenstrauß zone of northeastern Bavaria. This supports the idea that all three units are remnants of a huge complex which suffered a metamorphic overprint under medium-pressure conditions, probably in the early Devonian. Streng rejuvenation is found in the southern part of the Teplä-Domailice zone by which micas and even two hornblendes were reset to mid-Carboniferous ages. According to the geological setting, part of the apparently preDevonian dates may be explained by inherited argon from earlier metamorphic and magmatic events, e.g. the high-pressure metamorphism documented in eclogitic relics. However, excess argon, caused by the mid-Carboniferous overprint cannot be excluded.
KW  - Geochemie
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-87527
ER  - 
TY  - JOUR
A1  - Schüssler, Ulrich
A1  - Henjes-Kunst, Friedhelm
T1  - Petrographical and Geochronological Investigations on a Garnet-Tourmaline Pegmatite from Ringgold Knoll, Oates Coast, Antarctica
N2  - The Ringgold Knoll pegmatite, a late-stage member of the Granite Harbour Intrusives, crosscuts high-grade Wilson gneisses of the Oates Coast, which forms the westernmost part of the Wilson Terrane at the Pacific end of the Cambro-Ordovician Ross orogenic belt in West Antarctica. The pegmatite mineral assemblage consists of K-feldspar, plagioclase, quartz, garnet (almandinespessartine-pyrope), dark tourmaline (schorl-dravite), muscovite, apatite, monazite, zircon, blue AI-rich tourmaline and dumortierite in order of decreasing abundances. Major, minor and rare earth elements are reported for the greater part of the mineral assemblage. The time of pegmatite emplacement is constrained by Rb-Sr and Sm-Nd isochron ages of 492 ± 8 (2a) Ma and 500 ± 40 (2a) Ma, respectively. High initial 87Sr/86Sr of 0.7315 ± 0.0003 and low E Nd,t of -8.7 ± 1.2 strongly support an origin of the magma from highly evolved crustal source rocks. K-Ar and Ar-Ar model ages of about 470 to 475 Ma for igneous muscovite indicate that the pegmatite together with its wall rocks spent a prolonged period at elevated temperatures before final cooling below about 350 °C. The muscovite dates may give an estimate for the time of exhumation of the Oates Coast crystalline basement along two major late Ross orogenic detachment zones within the Wilson Terrane i.e. the Wilson and the Exiles thrusts (c.f. FLÖTTMANN and KLEINSCHMIDT, 1991).
N2  - Der Pegmatit vom Ringgold Knoll geh6rt zur spaten Gangfolge der Granite Harbour Intrusionen und durchschlagt hochgradig metamorphe Wilson Gneise der Oates Coast, die den westlichsten Teil des Wilson Terranes am pazifischen Ende des Kambro-Ordovizischen Ross Orogengiirtels in der Westantarktis bildet. Die pegmatitische Mineralparagenese besteht aus Kalifeldspat, Plagioklas, Quarz, almandin-spessartin-pyrop-betontem Granat, dunklem schorl-dravit-betontem Turmalin, Muscovit, Apatit, Monazit, Zirkon, blauem AI-reichem Turmalin und Dumortierit in der Reihenfolge abnehmenden Modalanteils. FUr den groBeren Teil der Minerale wurden Haupt-, Neben- und Seltenerdelemente bestimmt. Der Zeitpunkt der Pegmatitintrusion wird durch Rb-Sr und Sm-Nd Isochronenalter von 492 ± 8 (20") Ma bzw. 500 ± 40 Ma (20") datiert. Ein hohes "SrI" Sr Initialverhaltnis von 0,7315 ± 0,0003 und ein niedriger Wert flir E Nd,t von -8,7 ± 1,2 sprechen deutlich für eine Magmenherkunft von hochdifferenzierten krustalen Ausgangsgesteinen. K-Ar und Ar-Ar Modellalter von etwa 470 bis 475 Ma von magmatischem Muscovit zeigen, daB der Pegmatit und das Nebengestein eine langsame AbkUhlung auf Temperaturen unter etwa 350°C er1ebten. Die Muscovitdaten konnen als eine Zeitmarke gesehen werden fUr die Heraushebung des kristallinen Grundgebirges der Oates Coast entlang der zwei split Ross-orogenen Wilson und Exiles Hauptüberschiebungszonen im Wilson Terrane (FLÖTTMANN und KLElNSCHMlDT 1991).
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31789
ER  - 
TY  - JOUR
A1  - Schüssler, Ulrich
A1  - Okrusch, M.
A1  - Patzak, M.
A1  - Müller, P.
A1  - Kreuzer, H.
T1  - The polyphase thermal history of the Erbendorf-Vohenstrauß (ZEV) and the Erbendorf Greenschist (EGZ) zones of NE Bavaria in the light of Ar-Ar spectra
N2  - no abstract available
KW  - Erbendorf
KW  - Vohenstrauß
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-81862
ER  - 
TY  - CHAP
A1  - Schüssler, Ulrich
A1  - Okrusch, M.
A1  - Richter, P.
T1  - Amphibolites of the KTB target area Oberpfalz, Bavaria
N2  - No abstract available
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-38866
ER  - 
TY  - CHAP
A1  - Schüssler, Ulrich
A1  - Okrusch, M.
A1  - Richter, P.
A1  - Seidel, E.
T1  - Geochemistry of metabasites and element mobility
N2  - No abstract available
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-38880
ER  -