@article{ZobirOberhaensli2013, author = {Zobir, Soraya Hadj and Oberh{\"a}nsli, Roland}, title = {The sidi Mohamed peridotites (Edough Massif, NE Algeria) - evidence for an upper mantle origin}, series = {Journal of earth system science}, volume = {122}, journal = {Journal of earth system science}, number = {6}, publisher = {Indian Academy of Science}, address = {Bangalore}, issn = {0253-4126}, doi = {10.1007/s12040-013-0358-z}, pages = {1455 -- 1465}, year = {2013}, abstract = {The Hercynian Edough massif is the easternmost crystalline massif of the Algerian coast. It consists of two tectonically superposed units composed of micaschists, gneisses, and peridotite. This study concentrates on the small and isolated Sidi Mohamed peridotite outcrop area (0.03 km(2)). The Sidi Mohamed peridotite is composed mainly of harzburgites (Mg-rich olivine and orthopyroxene as major minerals). The Ni (2051-2920 ppm), Cr (2368-5514 ppm) and MgO (similar to 28-35 wt.\%) whole-rock composition and the relative depletion in Nb make these harzburgites comparable to depleted peridotites related to a subduction zone. We suggest that the Sidi Mohamed ultramafic body was derived directly from the upper mantle and tectonically incorporated into the gneiss units of the Edough metamorphic core complex in a subduction environment.}, language = {en} } @article{ZakariadzeKarpenkoBazylevetal.1998, author = {Zakariadze, G. S. and Karpenko, S. F. and Bazylev, B. A. and Adamia, S. A. and Oberh{\"a}nsli, Roland and Solov'eva, N. V. and Ljialikov, A. V.}, title = {Fragments of Pan-African paleooceanic complexes in the Dzirula salient of the Transcaucassian crystalline massif (petroloy, geochemistry, Sm-Nd age, problems of origin)}, year = {1998}, language = {en} } @article{ZakariadzeKarpenkoBazylevetal.1998, author = {Zakariadze, G. S. and Karpenko, S. F. and Bazylev, B. A. and Adamia, S. A. and Oberh{\"a}nsli, Roland and Solov'eva, N. A. and Lyalikov, A. V.}, title = {Petrology, geochemistry, and Sm-Nd age of the pre-Late Hercynian paleooceanic complex of the Dzirula salient, Transcaucasian Massif}, year = {1998}, language = {en} } @article{WolffBoenischTrackSchenketal.1997, author = {Wolff-Boenisch, D. and Track, T. and Schenk, D. and Oberh{\"a}nsli, Roland}, title = {Sorptionsverhalten von 2,4,6-Trinitrotoluol und 1,3-Dinitrobenzol an unterschidlichen Bodenmodellsubstanzen}, year = {1997}, language = {de} } @article{WilhelmAltenbergerOberhaensli2001, author = {Wilhelm, Stefan and Altenberger, Uwe and Oberh{\"a}nsli, Roland}, title = {Intrusive marbles in the Ivrea Zone (Italy) : evidence for melting of metacarbonates}, year = {2001}, language = {en} } @article{WichuraBousquetOberhaenslietal.2010, author = {Wichura, Henry and Bousquet, Romain and Oberh{\"a}nsli, Roland and Strecker, Manfred and Trauth, Martin H.}, title = {Evidence for middleUocene uplift of the East African Plateau}, issn = {0091-7613}, doi = {10.1130/G31022.1}, year = {2010}, abstract = {Cenozoic uplift of the East African Plateau has been associated with fundamental climatic and environmental changes in East Africa and adjacent regions. While this influence is widely accepted, the timing and the magnitude of plateau uplift have remained unclear. This uncertainty stems from the lack of datable, geomorphically meaningful reference horizons that could record surface uplift. Here, we document the existence of significant relief along the East African Plateau prior to rifting, as inferred from modeling the emplacement history of one of the longest terrestrial lava flows, the similar to 300-km-long Yatta phonolite flow in Kenya. This 13.5 Ma lava flow originated on the present-day eastern Kenya Rift flank, and utilized a riverbed that once routed runoff from the eastern rim of the plateau. Combining an empirical viscosity model with subsequent cooling and using the Yatta lava flow geometry and underlying paleotopography (slope angle), we found that the prerift slope was at least 0.2 degrees, suggesting that the lava flow originated at a minimum elevation of 1400 m. Hence, high paleotopography in the Kenya Rift region must have existed by at least 13.5 Ma. We infer from this that middle Miocene uplift occurred, which coincides with the two-step expansion of grasslands, as well as important radiation and speciation events in tropical Africa.}, language = {en} } @article{WenzelOberhaensliMezger2000, author = {Wenzel, T. and Oberh{\"a}nsli, Roland and Mezger, Klaus}, title = {K-rich plutonic rocks and lamprophyres from the Meissen Massif (northern Bohemian Massif) : Geochemical evidence for variably enriched lithospheric mantle sources}, year = {2000}, language = {en} } @article{WenzelMertzOberhaenslietal.1997, author = {Wenzel, T. and Mertz, D. and Oberh{\"a}nsli, Roland and Becker, Thomas and Penne, P.}, title = {Age, geodynamic setting, and mantle enrichment processes of a K-rich intrusion from the Meissen massif (northern Bohemian massif) and implications for related occurrences from the mid-European Hecynian}, year = {1997}, language = {en} } @article{WeberAbuAyyashAbueladasetal.2004, author = {Weber, Michael H. and Abu-Ayyash, Khalil and Abueladas, Abdel-Rahman and Agnon, Amotz and Al-Amoush, H. and Babeyko, Andrey and Bartov, Yosef and Baumann, M. and Ben-Avraham, Zvi and Bock, G{\"u}nter and Bribach, Jens and El-Kelani, R. and Forster, A. and F{\"o}rster, Hans-J{\"u}rgen and Frieslander, U. and Garfunkel, Zvi and Grunewald, Steffen and Gotze, Hans-J{\"u}rgen and Haak, Volker and Haberland, Christian and Hassouneh, Mohammed and Helwig, S. and Hofstetter, Alfons and Jackel, K. H. and Kesten, Dagmar and Kind, Rainer and Maercklin, Nils and Mechie, James and Mohsen, Amjad and Neubauer, F. M. and Oberh{\"a}nsli, Roland and Qabbani, I. and Ritter, O. and Rumpker, G. and Rybakov, M. and Ryberg, Trond and Scherbaum, Frank and Schmidt, J. and Schulze, A. and Sobolev, Stephan Vladimir and Stiller, M. and Th,}, title = {The crustal structure of the Dead Sea Transform}, year = {2004}, abstract = {To address one of the central questions of plate tectonics-How do large transform systems work and what are their typical features?-seismic investigations across the Dead Sea Transform (DST), the boundary between the African and Arabian plates in the Middle East, were conducted for the first time. A major component of these investigations was a combined reflection/ refraction survey across the territories of Palestine, Israel and Jordan. The main results of this study are: (1) The seismic basement is offset by 3-5 km under the DST, (2) The DST cuts through the entire crust, broadening in the lower crust, (3) Strong lower crustal reflectors are imaged only on one side of the DST, (4) The seismic velocity sections show a steady increase in the depth of the crust-mantle transition (Moho) from 26 km at the Mediterranean to 39 km under the Jordan highlands, with only a small but visible, asymmetric topography of the Moho under the DST. These observations can be linked to the left-lateral movement of 105 km of the two plates in the last 17 Myr, accompanied by strong deformation within a narrow zone cutting through the entire crust. Comparing the DST and the San Andreas Fault (SAF) system, a strong asymmetry in subhorizontal lower crustal reflectors and a deep reaching deformation zone both occur around the DST and the SAF. The fact that such lower crustal reflectors and deep deformation zones are observed in such different transform systems suggests that these structures are possibly fundamental features of large transform plate boundaries}, language = {en} } @article{WawrzenitzRomerOberhaenslietal.2006, author = {Wawrzenitz, Nicole and Romer, Rolf L. and Oberh{\"a}nsli, Roland and Dong, Shuwen}, title = {Dating of subduction and differential exhumation of UHP rocks from the Central Dabie Complex (E-China) : constraints from microfabrics, Rb-Sr and U-Pb isotope systems}, doi = {10.1016/j.lithos.2005.12.001}, year = {2006}, abstract = {The correlation of deformation fabrics and metamorphic reactions with geochronologic data of UHP metamorphic rocks demonstrate that the multistage subduction and exhumation history of the Central Dabie Complex requires rapid subduction and rapid initial exhumation. Moreover, these data show that volume diffusion is not the major resetting mechanism of radiogenic isotope systems. Thus, our age data do not simply reflect a thermal/cooling history. In the investigated section, the maximum age for UHP is given by the 244 +/- 3 Ma (2 sigma) U-Pb age of a pre-UHP titanite phenocryst that survived UHP metamorphism and subsequent tectonometamorphic events. A minimum age for UHP is set by the 238 +/- 1 Ma (2 sigma) U-238-Pb-206 mineral isochron age of titanite and cogenetic epidote. These minerals formed from local partial melts during ascent and their age suggests fast exhumation and emplacement in the middle crust. In the period of ca. 238-218 Ma, the UHP terrain records HT metamorphism, local partial melting, and extensive pervasive strain below the eclogite (jd+grt) stability field. Exhumation was polyphase with a first phase of fast exhumation, succeeded by episodes of HT metamorphism and concomitant deformation at deep/mid crustal level between 238 and 218 Ma. Slow exhumation related to the final emplacement of tectonic units along greenschist facies shear zones did not cease before ca. 209-204 Ma. The resetting and homogenization of radiogenic isotope systems were aided by dissolution precipitation creep, which was the dominant deformation mechanism in quartz-feldspar rocks, in combination with fluid influx. (c) 2005 Elsevier B.V. All rights reserved}, language = {en} }