TY - CHAP A1 - Riedel, Michael R. A1 - Ziemann, Martin Andreas A1 - Oberhänsli, Roland T1 - Pattern dynamics applied to the kinetics of mineral phase transformations N2 - Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006 Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7316 N1 - [Poster] ER - TY - JOUR A1 - Mesbahi, Fatemeh A1 - Mohajjel, Mohammad A1 - Oberhänsli, Roland A1 - Moazzen, Mohsen T1 - The mafic rocks along the North Tabriz Fault, possible remnants of Neo-Tethys oceanic crust in NW Iran JF - Geopersia N2 - The North Tabriz Fault is seismologically an active fault with current right lateral strike-slip movements. Restricted mafic to intermediate Fate Cretaceous igneous rocks are exposed along the North Tabriz Fault. Whole rock and clinopyroxene phenocrysts geochemistry were studied in order to characterize the petrogenesis of these mafic rocks and their possible relation to an oceanic crust. The results indicate a tholeiitic parental magma that formed in an evolved mid-ocean ridge tectonic setting similar to the Iceland mid-Atlantic ridge basalts. The ocean floor basalt characteristics give evidence of an oceanic crust along the North Tabriz Fault. Therefore, the trend of the North Tabriz Fault more likely marks a suture zone related to the closure of a branch of the Neo-Tethys Ocean in the NW Iran. This fault, in addition to the Caucasus and Zagros suture zones, compensates an important part of the convergence between the Arabian and Eurasian plates resulting from the Red Sea divergence. It is concluded that the North Tabriz Fault appears to be possible southeastern continuation of the North Anatolian suture zone. KW - North Tabriz Fault KW - Mafic Rocks KW - Tholeiite KW - Late Cretaceous Y1 - 2017 U6 - https://doi.org/10.22059/geope.2017.232747.648323 SN - 2228-7817 VL - 7 SP - 301 EP - 311 PB - Graduate Faculty of Environment, University of Theran CY - Tehran ER - TY - JOUR A1 - Ali, Saleem H. A1 - Giurco, Damien A1 - Arndt, Nicholas A1 - Nickless, Edmund A1 - Brown, Graham A1 - Demetriades, Alecos A1 - Durrheim, Ray A1 - Enriquez, Maria Amelia A1 - Kinnaird, Judith A1 - Littleboy, Anna A1 - Meinert, Lawrence D. A1 - Oberhänsli, Roland A1 - Salem, Janet A1 - Schodde, Richard A1 - Schneider, Gabi A1 - Vidal, Olivier A1 - Yakovleva, Natalia T1 - Mineral supply for sustainable development requires resource governance JF - Nature : the international weekly journal of science N2 - Successful delivery of the United Nations sustainable development goals and implementation of the Paris Agreement requires technologies that utilize a wide range of minerals in vast quantities. Metal recycling and technological change will contribute to sustaining supply, but mining must continue and grow for the foreseeable future to ensure that such minerals remain available to industry. New links are needed between existing institutional frameworks to oversee responsible sourcing of minerals, trajectories for mineral exploration, environmental practices, and consumer awareness of the effects of consumption. Here we present, through analysis of a comprehensive set of data and demand forecasts, an interdisciplinary perspective on how best to ensure ecologically viable continuity of global mineral supply over the coming decades. Y1 - 2017 U6 - https://doi.org/10.1038/nature21359 SN - 0028-0836 SN - 1476-4687 VL - 543 SP - 367 EP - 372 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Sheikholeslami, Mohammad Reza A1 - Oberhänsli, Roland A1 - Ghassemi, Mohammad R. T1 - Transpression tectonics in the eastern Binalud Mountains, northeast Iran; Insight from finite strain analysis, vorticity and Ar-40/Ar-39 dating JF - Journal of Asian earth sciences N2 - Different tectonic episodes from Late Triassic to recent times in the eastern Binalud Mountains have resulted from convergence and transpression between the Turan and Central Iran plates. Heterogeneous deformation and variable portions of pure and simple shear, demonstrated by finite strain and vorticity analysis in the Mashhad metamorphic rocks, indicate strain partitioning during the first tectonic episode. Modern strain partitioning is characterized by reverse and strike-slip faulting along the Neyshabur fault system and Shandiz fault zone in the southern and northern flanks of the eastern Binalud, respectively. Time-transgressive regional deformation migrated from the hinterland of the belt into the foreland basin, from northeast to the southwest of the mountains. Different generations of deformation resulted in obliteration of the subduction-related accretionary wedge, and growth of an orogenic wedge resulted from collision between the Central Iran and Turan plates. KW - Transpression KW - Binalud Mountains KW - Deformation KW - Orogenic wedge KW - Northeast Iran Y1 - 2019 U6 - https://doi.org/10.1016/j.jseaes.2019.04.014 SN - 1367-9120 SN - 1878-5786 VL - 179 SP - 219 EP - 237 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Scheffler, Franziska A1 - Immenhauser, Adrian A1 - Pourteau, Amaury A1 - Natalicchio, Marcello A1 - Candan, Osman A1 - Oberhänsli, Roland T1 - A lost Tethyan evaporitic basin BT - Evidence from a Cretaceous hemipelagic meta-selenite - red chert association in the Eastern Mediterranean realm JF - Sedimentology : the journal of the International Association of Sedimentologists N2 - Ancient evaporite deposits are geological archives of depositional environments characterized by a long‐term negative precipitation balance and bear evidence for global ocean element mass balance calculations. Here, Cretaceous selenite pseudomorphs from western Anatolia (‘Rosetta Marble’) — characterized by their exceptional morphological preservation — and their ‘marine’ geochemical signatures are described and interpreted in a process‐oriented context. These rocks recorded Late Cretaceous high‐pressure/low‐temperature, subduction‐related metamorphism with peak conditions of 1·0 to 1·2 GPa and 300 to 400°C. Metre‐scale, rock‐forming radiating rods, now present as fibrous calcite marble, clearly point to selenitic gypsum as the precursor mineral. Stratigraphic successions are recorded along a reconstructed proximal to distal transect. The cyclical alternation of selenite beds and radiolarian ribbon‐bedded cherts in the distal portions are interpreted as a two type of seawater system. During arid intervals, shallow marine brines cascaded downward into basinal settings and induced precipitation. During more humid times, upwelling‐induced radiolarian blooms caused the deposition of radiolarite facies. Interestingly, there is no comparable depositional setting known from the Cenozoic world. Meta‐selenite geochemical data (δ13C, δ18O and 87Sr/86Sr) plot within the range of reconstructed middle Cretaceous seawater signatures. Possible sources for the 13C‐enriched (mean 2·2‰) values include methanogenesis, gas hydrates and cold seep fluid exhalation. Spatially resolved component‐specific analysis of a rock slab displays isotopic variances between meta‐selenite crystals (mean δ13C 2·2‰) and host matrix (mean δ13C 1·3‰). The Cretaceous evaporite‐pseudomorphs of Anatolia represent a basin wide event coeval with the Aptian evaporites of the Proto‐Atlantic and the pseudomorphs share many attributes, including lateral distribution of 600 km and stratigraphic thickness of 1·5 to 2·0 km, with the evaporites formed during the younger Messinian salinity crisis. The Rosetta Marble of Anatolia may represent the best‐preserved selenite pseudomorphs worldwide and have a clear potential to act as a template for the study of meta‐selenite in deep time. KW - Blueschist metamorphism KW - depositional environment KW - evaporites KW - Neotethys KW - pseudomorphism KW - sedimentology Y1 - 2019 U6 - https://doi.org/10.1111/sed.12606 SN - 0037-0746 SN - 1365-3091 VL - 66 IS - 7 SP - 2627 EP - 2660 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Moazzen, Mohssen A1 - Oberhänsli, Roland A1 - Hajialioghli, Robab A1 - Moeller, Andreas A1 - Bousquet, Romain A1 - Droop, Giles A1 - Jahangiri, Ahmad T1 - Peak and post-peak P-T conditions and fluid composition for scapolite-clinopyroxene-garnet calc-silicate rocks from the Takab area, NW Iran N2 - The Takab calcareous rocks of northwest Iran crop out in association with a variety of metamorphic rocks including mafic granulites, amphibolites, granitic gneisses, pelitic schists and meta-ultramafic rocks. They can be divided into marbles and calc-silicate rocks on the basis of the dominance of calcite/dolomite and silicate minerals. Dominant peak metamorphic granulite facies assemblage of calc-silicate rocks is Scp + Grt(I) + Cpx + Cal + Qtz +/- Hbl(I). The decrease of temperature and pressure during exhumation produced post-peak metamorphic assemblages. Coronal garnet (Grt II) in the calc-silicate rocks was produced by retrograde reactions consuming plagioclase and clinopyroxene, while peak metamorphic garnet (Grt I) occurs as preserved xenoblastic grains in calcite and/or plagioclase (Pl II). Regional metamorphism took place at 740 degrees C and X-CO2 similar to 0.9. Garnet-clinopyroxene-plagioclase-quartz (GADS) barometry yields a pressure of 8-9 kbar, corresponding to a depth of ca. 24-27 km. This was followed by decompression and hydration during exhumation of the crustal rocks up to the surface. Secondary phases such as garnet (II) hornblende (II), plagioclase (II), zoisite and titanite (II) constrain the temperature and pressure of post-peak metamorphism as similar to 600 degrees C and similar to 6 kbar respectively and a fluid with XCO2 as low as 0.4. Halogens were near-absent during the peak metamorphic stage. The scapolite and hornblende crystallized underpeak metamorphic conditions contain very low fluorine and chlorine, whereas relatively high fluorine (similar to 0.8 wt%) in the titanite (II) and hornblende (II) suggests a possible infiltration of F-rich fluids into the calc-silicate rocks during retrogression. It is interpreted to be related to external fluids released during crystallisation of granitoid magmas and/or leucosome patches in the adjacent migmatites. Y1 - 2009 UR - http://eurjmin.geoscienceworld.org/ U6 - https://doi.org/10.1127/0935-1221/2009/0021-1887 SN - 0935-1221 ER - TY - JOUR A1 - Oberhänsli, Roland A1 - Koralay, E. A1 - Candan, Osman A1 - Pourteau, Amaury A1 - Bousquet, Romain T1 - Late cretaceous eclogitic high-pressure relics in the Bitlis Massif JF - Geodinamica acta : revue de géologie dynamique et de géographie physique N2 - A new occurrence of eclogites was found in the Kesandere valley in the eastern most part of the Bitlis complex, SE Anatolia. These high-pressure (HP) relics were preserved in calc-arenitic metasediments within the high-grade metamorphic basement of the Bitlis complex. The eclogitic parageneses were strongly overprinted during decompression and heating. These new eclogites locality complements the evidence of blueschist-facies metamorphism documented recently in the meta-sedimentary cover sequence of this part of the Bitlis complex. Thermodynamic calculations suggest peak conditions of ca. 480-540 degrees C/1.9-2.4GPa. New U/Pb dates of 84.4 +/-.9 and 82.4 +/-.9Ma were obtained on zircons from two Kesandere eclogite samples. On the basis of geochemical criteria, these dates are interpreted to represent zircon crystallization during the eclogitic peak stage. Kesandere eclogites differ from those previously described in the western Bitlis complex (Mt. Gablor locality) in terms of lithologic association, protolithic origin, and peak P-T conditions (600-650 degrees C/1.0-2.0GPa, respectively). On the other hand, eclogitic metamorphism of Kesandere metasediments occurred shortly before blueschist-facies metamorphism of the sedimentary cover (79-74Ma Ar-40/Ar-39 white mica). Therefore, the exhumation of Kesandere eclogites started between ca. 82 and 79Ma, while the meta-sedimentary cover was being buried. During this short time span, Kesandere eclogite were likely uplifted from similar to 65 to 35km depth, indicating a syn-subduction exhumation rate of similar to 4.3mm/a. Subsequently, eclogite- and blueschist-facies rocks were likely retrogressed contemporarily during collision-type metamorphism (around 72-69Ma). The Bitlis HP rocks thus sample a subduction zone that separated the Bitlis-Puturge (Bistun?) block from the South-Armenian block, further north. To the south, Eocene metasediments of the Urse formation are imbricated below the Bitlis complex. They contain (post Eocene) blueschists, testifying separation from the Arabian plate and southward migration of the subduction zone. The HT overprint of Kesandere eclogites can be related to the asthenospheric flow provoked by subducting slab retreat or break off. KW - eclogites KW - zircon KW - U KW - Pb ages KW - E Anatolia KW - subduction-collision Y1 - 2013 U6 - https://doi.org/10.1080/09853111.2013.858951 SN - 0985-3111 SN - 1778-3593 VL - 26 IS - 3-4 SP - 175 EP - 190 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Zakariadze, G. S. A1 - Karpenko, S. F. A1 - Bazylev, B. A. A1 - Adamia, S. A. A1 - Oberhänsli, Roland A1 - Solov'eva, N. V. A1 - Ljialikov, A. V. T1 - Fragments of Pan-African paleooceanic complexes in the Dzirula salient of the Transcaucassian crystalline massif (petroloy, geochemistry, Sm-Nd age, problems of origin) Y1 - 1998 ER - TY - JOUR A1 - Kroner, Alfred A1 - Oberhänsli, Roland A1 - Mezger, Klaus A1 - Teklay, M. T1 - Geochemistry, Pb-Pb single zircon ages and Nd-Sr isotope composition of Precambrian rocks from southern and eastern Ethiopia: implications for crustal evolution in east Africa Y1 - 1998 ER - TY - JOUR A1 - Hofer, H. E. A1 - Brey, G. P. A1 - Oberhänsli, Roland T1 - The determination of the oxidation state of iron in synthetic garnets by X-ray spectroscopy with the electron microprobe Y1 - 1996 ER -