East Vardar Ophiolite from North Macedonia revised within the GECCOSPARK know-how exchange programme (KEP) project funded by the Central European Initiative (CEI)

This contribution is part of a CEI-KEP project (Ref. No. 1206.006-19) titled “Promoting geological, e cological and cultural heritage through sustainable development and creation of geo-parks”. It includes the study of Mesozoic ophiolite rocks, which are interpreted as the remnants of the Vardar TethysOcean. The East Vardar ophiolites are composed of basic magmatic sequences (pillow basalts, sheeted dykes, and gabbros), associated with intermediate and acid magmatic intrusions having subduction-related affinity and locally bearing an adakitic signature (Božović et al., 2013; Boev et al., 2018). To give new< insights on these ophiolites, new samples were collected from the Lipkovo and Demir Kapija localities, in the northern and southern part of North Macedonia, respectively. Three groups of rocks are distinguished on the basis of whole-rock major and trace element composition and major element composition of clinopyroxene. Group 1 is characterized by tholeiitic basalts from Demir Kapija that exhibit slight enrichments in light-Rare Earth Element (L-REE) and slight negative Nb anomaly. These features are comparable with those of back-arc basin basalts. Groups 2 and 3 are represented by calcalkaline rocks, showing typical subduction-related chemical affinity, as exemplified by N-MORB normalized spider diagrams showing typical Nb and Ta and, locally, P and Ti, negative anomalies along with Th-U positive anomalies. Group 2 rocks, which are from Demir Kapija, exhibit a weak adakitic affinity, as they are characterized by high LREE/HREE fractionation, high Sr/Y and La/Yb ratios. Additional insights were provided by δ13C and δ34S analyses. Group 2 and 3 rocks show more pronounced negative δ13C (-22‰ to -18‰) and positive δ34S (+2.3‰ to +4.9‰) values compared to those of Group 1 rocks (δ13C: -16‰ to -10‰; δ34S: +0.7‰ to +2.4‰), suggesting that Group 2 and 3 rocks record comparatively higher metasomatic interaction of their mantle sources with slab-derived components. On the whole, the results show that magmatic rocks from ophiolites of East Vardar in the North Macedonia display a widespread supra-subduction chemical signature, indicating the formation of these ophiolites in an arc - back-arc ensialic setting. The data provide information about the geological evolution and setting of this area, which should be disseminated using a didactic approach and simple concepts appealing for “nonexperts”, emphasizing that such studies are crucial to understand a unique geological system, which has no analogues in the present

Geomorphology of the topmost part of the Bistra Mountain, Mavrovo Park, North Macedonia

Identification of the remnant traces of paleo-glaciers provides important proxies to understand the response of the environment to rapid climate changes. We present a 1:25,000 scale geomorphological map covering ∼12.5 km2 of the upper part of Mount Bistra (North Macedonia) on the basis of remote sensing analyses and geomorphological surveys. Particular attention is given to the description of glacial and periglacial landforms, to the reconstruction of single glacier shapes and to Equilibrium Line Altitude (ELA) value calculation. The results of the survey and the reconstructed ELAs indicate the occurrence of three glacial phases that led to the formation of frontal and lateral moraines. The age of these phases is tentatively attributed to the Late Pleistocene by comparing these ELAs with those of other Balkan mountains. This map is the first step of a wider project aimed at reconstructing the relation between climate change and geomorphic response in this area

Geomorphology of the topmost part of the Bistra Mountain, Mavrovo Park, North Macedonia

Identification of the remnant traces of paleo-glaciers provides important proxies to understand the response of the environment to rapid climate changes. We present a 1:25,000 scale geomorphological map covering ∼12.5 km2 of the upper part of Mount Bistra (North Macedonia) on the basis of remote sensing analyses and geomorphological surveys. Particular attention is given to the description of glacial and periglacial landforms, to the reconstruction of single glacier shapes and to Equilibrium Line Altitude (ELA) value calculation. The results of the survey and the reconstructed ELAs indicate the occurrence of three glacial phases that led to the formation of frontal and lateral moraines. The age of these phases is tentatively attributed to the Late Pleistocene by comparing these ELAs with those of other Balkan mountains. This map is the first step of a wider project aimed at reconstructing the relation between climate change and geomorphic response in this area

SUBDUCTION SIGNATURE OF THE VARDAR OPHIOLITE OF NORTH MACEDONIA: NEW CONSTRAINTS FROM GEOCHEMICAL AND STABLE ISOTOPE DATA

Volatiles such as carbon (C) and sulphur (S) are commonly transferred into the mantle from subduction of oceanic lithosphere and overlying sediments. C and S isotopic signatures of magmatic rocks could be used as proxies of the slab components involved in the petrogenesis of subduction-related ophiolites. Therefore, in this work we investigated the major and trace element composition, as well as the C and S elemental contents and isotopic ratios (13C/12C and 34S/32S) of subvolcanic and volcanic rocks of the Vardar ophiolites of North Macedonia, which represent the remnants of the Mesozoic Tethyan oceanic lithosphere formed in supra-subduction zone tectonic settings. The ophiolites were sampled at Lipkovo and Demir Kapija localities, in the northern and southern part of North Macedonia, respectively. Based on whole-rock major and trace element composition, three groups of rocks can be distinguished: i) Group 1 rocks, which are subalkaline basalts having backarc affinity, ii) Group 2a and iii) Group 2b rocks, which are calc-alkaline basalts having arc affinity, with and without adakitic signatures, respectively. The qualitative petrogenetic models indicate that studied rocks formed by partial melting of mantle sources variably metasomatized by subduction-related components, such as aqueous fluids, sediment melts, and adakitic melts. Accordingly, all the North Macedonia ophiolites are characterized by C and S signatures which deviate from those typical for mantle and Mid Ocean Ridge melts. The variably low δ13C values recorded by Group 1 and 2 rocks could be related to the different contributions of melts released by subducting sediments rich in organic matter. However, we cannot exclude that such C-enriched signature is the result of isotopic fractionation during degassing process. In contrast, the enriched S isotopic signatures of the North Macedonia ophiolites suggest a major involvement of melts derived from the subducting sediments rich in sulphate phases. In particular, the calc-alkaline basalts of Group 2 rocks record more positive δ34S values than the subalkaline basalts of Group 1 formed in backarc basin suggesting that the subarc mantle sources were more affected by slab-released fluids than those of the backarc basin, which were more distal from the trench

Carbon and sulphur isotopic composition of Vardar ophiolite of North Macedonia: implications for volatiles cycling in subduction zones.

The North Macedonia is part of the Dinaric-Hellenic belt, an Alpine collisional belt extending from Slovenia to Greece. It resulted from the Mesozoic-Cenozoic convergence between Eurasia and Adria, ophiolite obduction, and continental collision after the closure of the Tethys Ocean. In this work we investigated the subvolcanic and volcanic rocks of the Vardar ophiolites of the North Macedonia, which represent the remnants of the Mesozoic Tethyan oceanic lithosphere formed in supra-subduction zone tectonic setting. Samples were collected at Lipkovo and Demir Kapija localities, in the northern and southern part of North Macedonia, respectively. Based on whole-rock major and trace element composition, two main groups of rocks can be distinguished: i) Group 1 rocks, which are subalkaline basalts showing backarc affinity and ii) Group 2 rocks, which are calc-alkaline basalts showing arc affinity. Petrogenetic modelling, based on trace and REE, indicates that Group 1 mantle sources were affected by limited metasomatic processes by slab-released components, in particular aqueous fluids and sediment melts, whereas the Group 2 mantle sources were strongly metasomatized by sediment melts and/or adakitic melts. In addition to this, the isotopic ratios of volatiles such as carbon (C) and sulphur (S) were also investigated to better constrain the nature and composition of the slab-components responsible for the metasomatism. In fact, volatiles are commonly transferred into the mantle from subduction of oceanic lithosphere and overlying sediments, whose C and S isotopic composition is well distinguishable from that of the mantle. The Group 1 rocks exhibit C-enriched and S-depleted signatures slightly different from those typical for the mantle, indicating a minor involvement of melts from the subducting sediments in the backarc basin settings. On the contrary, the C-depleted and S-enriched isotopic signatures of the Group 2 rocks suggest a major involvement of melts derived from the subducting sediments rich in organic matter and sulphate phases. Therefore, both geochemical and isotopic data of the North Macedonia ophiolites indicate that the sub-arc mantle sources are more affected by slab-released fluids than those of the backarc basin, which are more distal from the trench. This approach may be useful to better constrain the composition of the metasomatic agents, as well as to understand the origin and the fate of volatiles near subduction zones

Chemical signature of the basaltic rocks from the supra-subduction zone Vardar ophiolite (North Macedonia): new insights on the metasomatism of sub-arc upper mantle using geochemical and stable isotope data

In the upper mantle, volatiles control its composition, partial melting conditions, as well as the ascent rate of the formed melts. As consequence, volatile composition of the mantle is, in turn, recorded in the melts and, therefore, in the erupted basaltic rocks. Despite their importance, origin, budget, and fluxes of the volatiles in the upper mantle are poorly constrained. It is well known that the main input of mantle volatiles, such as carbon (C) and sulphur (S), represents components released from the subducting slab, e.g., oceanic rocks and sediments, whose have characteristic isotopic signatures. In this view, studies of isotopic ratios of volatiles of subduction-related magmatic rocks could be used to identify the chemical components released by the subducting slab metasomatizing the upper mantle. To confirm this hypothesis, we investigated the major and trace element composition, as well as the C and S elemental contents and isotopic ratios of subvolcanic and volcanic rocks of the Vardar ophiolites of North Macedonia, which represent remnants of the Mesozoic Tethyan oceanic lithosphere formed in supra-subduction zone tectonic settings. The ophiolites were sampled at Lipkovo and Demir Kapija localities, in the northern and southern part of North Macedonia, respectively. Based on whole-rock major and trace element composition, two main groups of rocks can be distinguished: i) Group 1 rocks, which are subalkaline basalts with backarc affinity and ii) Group 2 rocks, which are calc-alkaline basalts with arc affinity. The petrogenetic modelling based on trace and Rare Earth Elements, indicates that Group 1 mantle sources were affected by limited metasomatic processes by slab-released components, in particular aqueous fluids and sediment melts, whereas the Group 2 mantle sources were strongly metasomatized by sediment melts and adakitic melts. Accordingly, the Group 1 rocks exhibit C-enriched and S-depleted isotopic signature, indicating a minor involvement of melts from the subducting sediments. On the other hand, the C-depleted and S-enriched isotopic signatures of the Group 2 rocks suggest a major involvement of melts derived from the subducting sediments rich in organic matter and sulphate phases Therefore, both geochemical and isotopic data of the subvolcanic and volcanic samples of the North Macedonia ophiolites show that the sub-arc mantle sources are more affected by slab-released fluids than those of the backarc basin, which are more distal from the trench. Thus, combining the geochemical and isotopic data of subvolcanic and volcanic samples of complex geological framework can contribute to reconstruct the geodynamic scenarios, such as that of the Vardar ophiolites in the Dinaric-Hellenic belt. In addition, this approach may be useful to better understand the global geodynamic cycles of volatiles reconstructing their origin, budget, and isotopic composition, and understand the impacts on climate and environment from local to global scale

Exotic foods reveal contact between South Asia and the Near East during the second millennium BCE

Here we report the identification of staple and exotic food remains in Bronze and Early Iron Age dental calculus from the Southern Levant. The analysis of dietary plant microremains and proteins sheds new light on consumed exotic foods from South and East Asia during the second millennium BCE. We provide the earliest direct evidence in the Mediterranean to date for the consumption of sesame, soybean, probable banana, and turmeric. The recovery and identification of diverse foodstuffs using molecular and microscopic techniques enables a new understanding of the complexity of early trade routes and nascent globalization in the ancient Near East and raises questions about the long-term maintenance and continuity of this trade system into later periods.Although the key role of long-distance trade in the transformation of cuisines worldwide has been well-documented since at least the Roman era, the prehistory of the Eurasian food trade is less visible. In order to shed light on the transformation of Eastern Mediterranean cuisines during the Bronze Age and Early Iron Age, we analyzed microremains and proteins preserved in the dental calculus of individuals who lived during the second millennium BCE in the Southern Levant. Our results provide clear evidence for the consumption of expected staple foods, such as cereals (Triticeae), sesame (Sesamum), and dates (Phoenix). We additionally report evidence for the consumption of soybean (Glycine), probable banana (Musa), and turmeric (Curcuma), which pushes back the earliest evidence of these foods in the Mediterranean by centuries (turmeric) or even millennia (soybean). We find that, from the early second millennium onwards, at least some people in the Eastern Mediterranean had access to food from distant locations, including South Asia, and such goods were likely consumed as oils, dried fruits, and spices. These insights force us to rethink the complexity and intensity of Indo-Mediterranean trade during the Bronze Age as well as the degree of globalization in early Eastern Mediterranean cuisine.Protein spectra have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository (https://www.ebi.ac.uk/pride) under the dataset identifier PXD021498