Petrology, geochemistry and Sm-Nd analyses on the Balkan-Carpathian Ophiolite (BCO – Romania, Serbia, Bulgaria): Remnants of a Devonian back-arc basin in the easternmost part of the Variscan domain

Neoproterozoic-paleozoic evolution of the Drina formation (Drina-Ivanjica entity)

“…The basic/metabasic rocks as conditional markers of crustal extension and the subsequent oceanization are in modern-day Central Europe and SEE, nevertheless, distributed on the both sides of Early Paleozoic Gondwana and formerly juxtaposed Laurasia. These occurrences of (meta)basic rocks are often referred to as "Variscan ophiolites" (e.g., IVAN & MÉRES, 2012;PLISSART et al, 2017). The presence of early Paleozoic (meta)basic rocks in Central Europe and SEE can be recognized either as a remnant of the formerly accreted Cadomian arc which was in turn developed in a back-arc position during Neoproterozoic to Ordovician times (opening of the proto-Rheic Ocean), or as the result of Devonian back-arc plate divergence of internal parts of the orogen.…”

Multi‐kilometre long pathway of geofluids migration: Clues concerning an ophiolite serpentinization setting possibly responsible for the inferred abiotic provenance of methane in thermal water outflows of the South‐West Carpathians (Romania)

“…Alternatively, the region incorporates (e.g. Plissart et al., 2017, and references therein) the so‐called “Tisoviţa‐Iuţi” ultramafic rocks massif, whose age is Devonian. In serpentinized dunites belonging to that ophiolite body, a well drilled at Tisoviţa (some 40‐km south of Băile Herculane—Figure 1a) has intercepted, in the 810–812‐m‐depth range, a permeable domain which provided (Filipescu & Humă, 1979) gas consisting of 69.1 vol.% CH 4 , and 28.7 vol.% H 2 .…”

“…We therefore primarily used, within the present study, ionic composition analyses which we had recently conducted on thermal water discharges that conveyed the inferred abiotic CH 4 . Those water composition data were corroborated with previously published chemical and isotopic gas analyses (Cosma, Italiano, Baciu, Ristoiu, and Etiope, 2003; Cosma & Ristoiu, 1999; Filipescu & Humă, 1979; Ionescu et al., 2017; Mastan, Cosma, & Znamirovschi, 1982; Mastan, Znamirovschi, and Cosma, 1982; Mastan, Znamirovschi, Cosma, & Pop, 1981), with geological‐structural information (Iancu, Berza, Seghedi, & Marunţiu, 2005; Iancu & Seghedi, 2017; Iancu, Seghedi, Mărunţiu, & Strusievicz, 1990; Năstăseanu, Iancu, & Russo‐Săndulescu, 1988; Plissart, Diot, Monnier, & Mărunţiu, 2018; Plissart et al., 2017), as well as with recent seismic tomography results (Zaharia, Grecu, Popa, Oros, & Radulian, 2017), and with data on the local seismic activity (International Seismological Centre, 2019; Shebalin et al., 1998).…”

“…Immediately above Cornereva Nappe it is positioned Sirinia Nappe (Figure 1), which incorporates the Devonian‐age Tisoviţa–Iuţi mafic–ultramafic body. The latter crops out (Plissart et al., 2017, and references therein) over ~70 km 2 , extending also further to the NNW, beneath an overthrusted tectonic unit (Plissart et al., 2018). Sirinia Nappe includes as well (Iancu et al., 1990) reworked Tisoviţa–Iuţi rock assemblages, embedded—as up to tens of metres large blocks—in the Baicu conglomerates (Figure 1), of Carboniferous–Permian age.…”

Efflorescent Sulfate Crystallization on Fractured and Polished Colloform Pyrite Surfaces: A Migration Pathway of Trace Elements

“…Others [41,42] suggest the influence of another undiscovered magmatic source of hydrothermal fluids in depth in addition to the Sveti Nikola pluton. The low-metamorphic rocks of DFC, which form the Paleozoic core of the Alpine Berkovitsa anticline, are a set of ophiolite (Cherni Vrah complex), island-arc (Berkovitsa complex), and continental remnants (Dalgi Del complex) related to the evolution of the Proto-Tethys Ocean (Cambrian-Ordovician age, [43][44][45]), as the ophiolite part was dated back to be Early Devonian and related to the Southern Variscan suture [46]. The low-metamorphic rocks of Dalgi Del complex occur to the south of the region shown on Figure 1.The Ag-Pb metasomatic replacement mineralization spatially associates with siderite bodies, which are hosted by thick marble layers in the metamorphic series (Berkovitsa complex) outlined on an area extending 0.5 km north-northwest of the village of Martinovo to the north of the village of Zhelezna.…”