140,127 research outputs found
Rizzo G., Dilek Y., Buccione, R., Dichicco M., Punturo R., 2024. Asbestos minerals, health risk or Earth resource? The serpentinites of the ophiolitic sequence in the Pollino Massif (Southern Italy). Workshop on Advanced X-ray characterization technologies in Earth Sciences ZAG – Slovenian National Building and Civil Engineering Institute 27-29 February 2024, Ljubljana (Slovenia).
No full textFORMATION OF MELANGES, BROKEN FORMATIONS, AND MASS-TRANSPORT CHAOTIC DEPOSITS DURING THE ORDOVICIAN TACONIC OROGENY: EXAMPLES FROM CENTRAL AND NORTHERN APPALACHIAN OROGENIC BELT, EASTERN USA
No full textChaos and geodynamics: mélanges, mélange-forming processes and their significance in the geological record. Preface to Special Issue
No full textMélanges occur extensively in accretionary and collisional orogenic belts around the world, and represent disrupted and chaotic units including sedimentary, magmatic and metamorphic rocks (commonly as exotic blocks) mixed by stratal disruption and tectonic, diapiric and/or sedimentary processes Although numerous papers and books have been published on mélanges, the definition and the geological significance of mélanges are still a matter of debate and controversy. The mechanisms that are responsible for the formation of mélanges may occur in a range of geological environments from the shallowest geosphere to significant crustal depths, associated with subduction zone tectonics, en-mass sedimentary processes, slope tectonics, in situ fluidization and mud diapirism, strike-slip tectonics, or due to the interplay of some of these processes. Although mélanges may characterize diverse geodynamic environments of formation, they are commonly associated with subduction of oceanic lithosphere, collisional events (arc-continent and continentcontinent), and intra-continental deformation including rifting and passive margin evolution. Hence, mélanges are cogenetic with emplacement of ophiolites, advancement of thrust and nappe sheets, evolution of foreland basins, formation of submarine landslides (olistostromes) and seismic events. Mélange formation is also involved in the mechanical stability of accretionary and orogenic wedges, and in the redistribution of earth materials through the processes of offscraping, underplating, mass-transport movements, subduction channel flow, and mud diapirism. Therefore, mélanges and mélange-forming processes are intimately linked with tectonics and tectonically induced geological processes in crustal evolution, and they constitute a significant component of the Earth history. Hence, further systematic and process-oriented, inter-disciplinary studies of mélanges should provide much-needed information about orogenic processes and crustal growth. Furthermore, the results of these mélange studies should also bemost insightful for the recognition of these chaotic rock bodies in the Precambrian greenstone belts. This Special Issue is a result of series of scientific sessions on mélanges that we convened at the GSA Global Meeting, Tectonic Crossroads, held in Ankara, Turkey in October 2010, the European Geosciences Union General Assembly in Vienna, Austria in May 2010, and the American Geophysical Union Fall Meeting in San Francisco, California, in December 2011. The papers in this Special Issue present the most up-to-date observations and interpretations on various mélange types and mélange forming processes from around the world. The geographic locations of the mélanges covered in this Special Issue are shown in Fig. 1. This Special Issue makes a significant contribution to the mélange concept, streamlines the definitions and classifications ofmélanges and broken formations, and provides a rich archive of well-documented mélange occurrences from diverse geological environments
Chaos and geodynamics: Melanges, melange-forming processes and their significance in the geological record
No full textTectonophysics Special Issue: Chaos and geodynamics: Melanges, melange-forming processes and their significance in the geological record
No full textVolume Speciale della rivista Tectonophysics pubblicata da Elsevier Science
Melénge and mélange-forming processes: case studies from the Apennines, Appalachian and New Zealand.
No full textFormation of mélanges, broken formations and mass-transport chaotic deposits during the Ordovician Taconic orogeny: examples from Central and Northern Appalachian orogenic belt, Eastern USA
No full textGeochronology and Petrology of the Early Carboniferous Misho Mafic Complex (NW Iran), and Implications for the Melt Evolution of Paleo-Tethyan Rifting in Western Cimmeria
No full textWe report new petrological, geochemical and geochronological data from the Misho Mafic Complex (NWIran), which represents a significant component of the West Cimmerian domain in Paleo-Tethys. The Misho Mafic Complex (MMC) mainly consists of gabbros crosscut by abundant basaltic dykes and the overlying basaltic sheeted dyke complex. Gabbros are intrusive into the Precambrian continental basement representing the northern margin of Gondwana. The U–Pb zircon age of a leucogabbro dyke reveals that the igneous emplacement age of theMMC is 356.7±3.4 Ma(Early Carboniferous). The gabbros and basaltic dykes are represented by (1) a subgroup
of rocks showing normal mid-ocean ridge basalt (N-MORB) affinity, and (2) another subgroup of rocks displaying plume-type MORB (P-MORB) affinity. These subgroups of rocks are coeval. The N-MORB rocks have almost flat N-MORB normalized incompatible element patterns, low Th/Yb, Ta/Yb, Zr/Y ratios, and high Zr/Nb ratios. The P-MORB rocks show significant OIB-type trace element signatures, such as enrichments in Th, Ta, Nb and light rare earth elements (LREE) with respect to N-MORB composition, high Th/Yb, Ta/Yb, Zr/Y ratios, and low Zr/Nb ratios. Petrogenetic modeling suggests that N-MORB rocks were generated by ~13% partial melting of a depletedMORB mantle (DMM) source,whereas P-MORB rocks were generated by ~4–6% partialmelting of a DMM source metasomatized by variable proportions of OIB-type (plume-type) enriched components. The mantle melting for both N-MORBs and P-MORBs appears to have started initially deep in the garnet-facies mantle,
and then shifted to shallowlevels in the spinel-facies mantle where it experienced higher degrees of melting.
The MMC collectively formed as a product of interaction between a depleted MORB-type asthenosphere and plume-typematerial. Itsmafic–ultramafic rocks represent an early Carboniferous magmatic event developed during the continental break-up of the northern edge of Gondwana that led to the opening of Paleo-Tethys, that was
originally triggered by a mantle plume. This model is consistent with well-documented late Devonian–early Carboniferous mantle plume activity to the east, along the Paleo-Tethys margins in central-eastern Asia, and suggests that the initial rift-drift tectonics of Paleo-Tethys was strongly affected by plume-related magmatism and associated lithospheric weakening at a regional scale
Morphological complexity within and across boundaries: in honour of Asli Göksel/ edited by Asli Gürer, Dilek Uygun Gökmen, Balkiz Öztürk.
No full textIncludes bibliographical references and index."This volume brings together a collection of original articles investigating state-of-the-art themes in morphology. The papers in the volume provide an in-depth analysis for spoken and sign languages within morphological word domain, morphosyntax and morphophonology. Bringing data from a variety of languages including Turkish, some understudied ones (e.g. Turkish Sign Language, Late Ottoman Turkish) and also endangered languages (e.g. Karachay-Balkar, Sauzini, Cappadocian, Aivaliot and Pharasiot Greek), the volume will be of special interest to a wide audience ranging from typologists to theoretical linguists and graduate students in linguistics and is expected to generate further research on the above mentioned languages, as well as to contribute to the cross-linguistic literature on the themes explored in the volume"--Introduction: In honor of Asli Göksel / Asli Gürer, Dilek Uygun Gökmen & Balkiz Öztürk -- Abstraction vs. analogy in Turkish aorist / Mine Nakipoğlu & Elise Michon -- Word formation through derivation vs. compounding : perspectives from child language acquisition of Turkish / Nihan Ketrez -- Restrictive relative clauses in the Greek dialects of Pharasa and Cappadocia / Metin Bağrıaçık -- Person indexing in Sauzini : subject vs. non-subject markers / Eser Taylan -- Subject marking of -DIK/-(y)AcAK complement clauses in written Turkish of the late Ottoman period (1860-1914) / Celia Kerslake -- Structure of plural pronoun constructions / Tacettin Turgay & Balkız Öztürk -- Paradigm leveling and regularization derive variation in stress : a corpus study on Turkish non-final stress at the morphology-phonology interface / Barış Kabak & Janne Lorenzen -- The great divide : Parts of speech and their consequences for the phonological shape of Turkish words / Markus A. Pöchtrager -- Variability in the realization of agreement in Turkish : a morphotactic account / Güliz Güneş -- Same exponent, different strength : a gradient harmonic account of allomorphy in Greek / Anthi Revithiadou -- Morphosyntax-prosody mismatches in Karachay Balkar : an analysis of narrow focus constructions / Asli Gürer & Dilek Uygun Gökmen -- Aspects of clause structure and morphology in Turkish Sign Language / Kadir Gökgöz & Hande Sevgi -- The universal quantifier 'all' in Turkish Sign Language / Burcu Saral & Meltem Kelepir -- Null arguments in Turkish Sign Language / Demet Kayabaşı Hande Sevgi & A. Sumru Özsoy.1 online resource
Continental margin ophiolites of Neotethys: remnants of ancient Ocean–Continent Transition Zone (OCTZ) Lithosphere and their geochemistry, mantle sources and melt evolution patterns.
No full textWe present an overview of the geology, geochemistry and petrogenesis of continental margin ophiolites (CMO), which represent the lithospheric remnants of rift-generated paleo ocean continent transition zones (OCTZ) in orogenic belts. The igneous stratigraphy and geochemical signatures of Neotethyan CMOs reflect the extent of geochemical heterogeneity, partial melting degrees, and melt evolution patterns in the continental lithospheric mantle prior to the onset of seafloor spreading in rifted margins. Basaltic rocks of the Jurassic CMOs in the External Ligurian units of the Northern Apennines have N-MORB and G-MORB affinities with strong HREE/MREE depletion, and represent the products of partial melting of a heterogeneous subcontinental lithospheric mantle containing small volumes of garnet pyroxenite layers. These extrusive rocks were erupted directly on the exhumed fertile spinel lherzolites of Adria during its OCTZ evolution. Volcanic rocks of the Triassic CMOs in the Albanide-Hellenide orogenic belt are represented by calc-alkaline suites; alkaline basalts and subordinate trachybasalts, trachyandesites, and trachytes; transitional to sub-alkaline plume-type P-MORB basalts; sub-alkaline enriched, E-MORB basalts; and, sub-alkaline N-MORB basalts. Upper mantle peridotites are not exposed. Magmas of these extrusive rock associations were derived from compositionally distinct mantle sources, which were affected by previous subduction and plume events in the geological history of the region. The CMOs in the Zagros orogenic belt include metamorphosed lherzolites with gabbro and mafic dike intrusions, which show N-MORB and G-MORB affinities. Basalts and basaltic andesites making up the majority of the Zagros volcanic sequences have E-MORB and P-MORB affinities, whereas minor alkaline rocks that are composed of basalts, trachybasalts and trachytes display OM signatures. The mantle sources of the Zagros CMOs were progressively enriched in Th and Nb. The OLB component of the mantle beneath the Zagros OCTZ was derived from previous plume events during the early Carboniferous, when Paleotethys was undergoing its rift-drift tectonics. The observed differences in the igneous stratigraphy and geochemical affinities of these Neotethyan CMOs are a result of extreme mantle heterogeneity caused by previous subduction and plume events during the Wilson Cycle evolution of the older Paleotethys
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