scholarly journals Petrology, geochemistry and tectono-magmatic affinity of gabbroic olistoliths from the ophiolite mélange in the NW Dinaric-Vardar ophiolite zone (Mts. Kalnik and Ivanščica, North Croatia)

2015 ◽  
Vol 58 (1) ◽  
pp. 25-49 ◽  
Author(s):  
Boško Lugović ◽  
Damir Slovenec ◽  
Ralf Schuster ◽  
Winfried H. Schwarz ◽  
Marija Horvat
Keyword(s):  
Ophiolite Mélange ◽  
Ophiolite Melange

scholarly journals Geochemistry, petrology and tectonomagmatic significance of basaltic rocks from the ophiolite mélange at the NW External-Internal Dinarides junction (Croatia)

2010 ◽  
Vol 61 (4) ◽  
pp. 273-292 ◽  
Author(s):  
Damir Slovenec ◽  
Boško Lugović ◽  
Irena Vlahović
Keyword(s):  
Mantle Source ◽  
Spreading Ridge ◽  
Accretionary Wedge ◽  
Carbonate Sediments ◽  
Basaltic Rocks ◽  
Depleted Mantle ◽  
Unit Form ◽  
Ophiolite Mélange ◽  
Internal Dinarides ◽  
Ophiolite Melange

Geochemistry, petrology and tectonomagmatic significance of basaltic rocks from the ophiolite mélange at the NW External-Internal Dinarides junction (Croatia)At the NW inflexion of the Sava-Vardar Suture Zone ophiolite mélanges, known as the Kalnik Unit, form the surface of the slopes of several Pannonian inselbergs in the SW Zagorje-Mid-Transdanubian Zone. The Mt Samoborska Gora ophiolite mélange, thought to be a part of the Kalnik Unit, forms a separate sector obducted directly onto Dinaric Triassic carbonate sediments. Basaltic rocks, the only magmatic rocks incorporated in the mélange, include Middle-Triassic (Illyrian-Fassanian) alkali within-plate basalts and Middle Jurassic (uppermost Bathonian-Lower Callovian) tholeiitic basalts. The latter sporadically constitute composite olistoliths, and are geochemically divided into N-MORB-like (high-Ti basalts) and transitional MORB/IAT (medium-Ti basalts). These geochemically different rocks suggest crystallization at various tectonomagmatic settings, which is also indicated by the rock paragenesis and host clinopyroxene compositions. Alkali basalts reflect melts derived from an OIB-type enriched mantle source [Ti/V= 62.2-82.4; (La/Lu)cn= 6.4-12.8] with Nd-Sr isotope signatures close resembling the Bulk Earth [εNd(T=235 Ma)= + 1.6 to + 2.5]. They are recognized as preophiolite continental rift basin volcanic rocks that closely predate the opening of the Repno oceanic domain (ROD) of the Meliata-Maliac ocean system. The high-Ti and medium-Ti basalts from composite blocks derived from a similar depleted mantle source (εNd(T=165 Ma) = + 6.01 vs. + 6.35) succesively metasomatized by expulsion of fluids from a subducting slab leading to a more pronounced subduction signature in the latter [Ti/V=31.6-44.8 and (Nb/La)n=0.67-0.90 vs. Ti/V=21.5-33.9 and (Nb/La)n=0.32-0.49]. These composite blocks indicate crust formation in an extensional basin spreading over the still active subducting ridge. The majority of high-Ti basalts may represent the fragments of older crust formed at a spreading ridge and incorporated in the mélange of the accretionary wedge formed in the proto-arc-fore-arc region. The Mt Samoborska Gora ophiolite mélange represents the trailing edge of the Kalnik Unit as a discrete sector that records the shortest stage of tectonomagmatic evolution related to intraoceanic subduction in the ROD.

scholarly journals Mineral Chemistry Perspective of Nain Ophiolite Mélange, Central Iran

2019 ◽  
Vol 116 (10) ◽  
pp. 1742
Author(s):  
Alireza Eslami ◽  
Jyotisankar Ray ◽  
Madhuparna Paul ◽  
Sonia Sarkar ◽  
Mousumi Banerjee ◽  
...  
Keyword(s):  
Mineral Chemistry ◽  
Central Iran ◽  
Ophiolite Mélange ◽  
Ophiolite Melange

scholarly journals Cretaceous to Miocene NW Pacific Plate kinematic constraints: Paleomagnetism and Ar-Ar geochronology in the Mineoka Ophiolite Melange (Japan)

2020 ◽  
Author(s):  
Ariuntsetseg Ganbat ◽  
Daniel Pastor-Galán ◽  
Naoto Hirano ◽  
Norihiro Nakamura ◽  
Hirochika Sumino ◽  
...  
Keyword(s):  
Pacific Plate ◽  
Kinematic Constraints ◽  
Ophiolite Mélange ◽  
Ar Geochronology ◽  
Ophiolite Melange
Sign in / Sign up

Export Citation Format

Share Document