Geochemistry, Sr-Nd-Pb isotopes and geochronology of amphibole- and mica-bearing lamprophyres in northwestern Iran: Implications for mantle wedge heterogeneity in a paleo-subduction zone

Highlights: • Northwestern Iranian lamprophyres have alkaline and calc-alkaline nature. • Studied lamprophyres are emplaced during Late Cretaceous to Late Miocene time. • Lamprophyres originated from different metasomatised lithospheric mantle. Abstract: Lamprophyres of different age showing distinctive mineralogy, geochemistry and isotopic ratios are exposed in northwestern Iran. They can be divided into Late Cretaceous sannaite, Late Oligocene-Early Miocene camptonite (amphibole-bearing) and Late Miocene minette (mica-bearing) and spessartite (amphibole-bearing) lamprophyres. Sannaites have high-Ti amphibole along with high-Ti and Al clinopyroxene, and they are characterised by homogeneous enrichment in incompatible trace elements with troughs at Pb. Spessartites have hornblende and low-Al and Ti clinopyroxene, and they are characterised by enriched incompatible trace element pattern with depletions of Nb, Ta, Pb, and Ti with respect to large ion lithophile elements. Minettes have high-Ti and Al brown mica and low-Al and Ti clinopyroxene, and similarly to spessartite, are characterised by fractionation of high field strength elements with respect to large ion lithophile elements, with troughs at Nb, Ta, and Ti and a peak at Pb. Minettes show high initial 87Sr/86Sr values up to 0.70760 and low initial 143Nd/144Nd down to 0.512463 with a negative correlation, consistent with the trace element distribution related with an enriched mantle source modified after sediment recycling during subduction and continental collision. Cretaceous sannaites and Early Miocene spessartites show low initial 87Sr/86Sr approaching 0.70447 and high 143Nd/144Nd values up to 0.512667, which are consistent with a depleted within-plate mantle source. Minette and spessartite lamprophyres show high initial 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb values, whereas sannaites have lower, but variable, initial 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb values with respect to those of calc-alkaline lamprophyres. Minettes originated by partial melting of a metasomatised lithospheric mantle following siliciclastic sediment recycling by subduction. In contrast, sannaites were generated from the partial melting of a similar lithospheric mantle that was metasomatised by within-plate agents

High-K volcanism in the Afyon region, western Turkey: from Si-oversaturated to Si-undersaturated volcanism

Volcanic rocks of the Afyon province (eastern part of western Anatolia) make up a multistage potassic and ultrapotassic alkaline series dated from 14 to 12 Ma. The early-stage Si-oversaturated volcanic rocks around the Afyon city and further southward are trachyandesitic volcanic activity (14.23 ± 0.09 Ma). Late-stage Si-undersaturated volcanism in the southernmost part of the Afyon volcanic province took place in three episodes inferred from their stratigraphic relationships and ages. Melilite– leucitites (11.50 ± 0.03 Ma), spotted rachyandesites, tephryphonolites and lamproites (11.91 ± 0.13 Ma) formed in the first episode; trachyandesites in the second episode and finally phonotephrites, phonolite, basaltic trachyandesites and nosean-bearing trachyandesites during the last episode. The parameter Q [normative q-(ne + lc + kls + ol)] of western Anatolia volcanism clearly decreased southward with time becoming zero in the time interval 10–15 Ma. The magmatism experienced a sudden change in the extent of Si saturation after 14 Ma, during late-stage volcanic activity of Afyon volcanic province at around 12 Ma, though there was some coexistence of Si-oversaturated and Si-undersaturated magmas during the whole life of Afyon volcanic province

Recycling plus : a new recipe for the formation of Alpine-Himalayan orogenic mantle lithosphere

The origin of the lithospheric mantle beneath accretionary orogens is enigmatic; although severe compression of the buoyant crust occurs, the mantle lithosphere is generally thought to be removed and returned to the convecting mantle. We suggest that during the accretion of oceanic arcs and small continental blocks in the Mediterranean region, and more generally throughout the whole Alpine-Himalayan orogenic belt, the mantle lithosphere is newly created and composed of intimately mixed peridotite and crustal material from the forearc region. Potassium-rich volcanic rocks emplaced sometimes more than 30Ma after the formation of this lithosphere carry evidence for the presence of extremely depleted peridotite in their sources, but also for mica-bearing pyroxenites formed by reaction between subducted continental sediments and peridotite. Olivines crystallized from the magmas and mantle-xenocrysts derived from the enriched mantle, have elevated concentrations of Li that correlate positively with ⁸⁷Sr/⁸⁶Sr of the lavas, indicative of an origin from continental crust-derived sediments. If much of the continental crust is formed in accretionary orogens of this type, then extensive tracts of the continental lithosphere may contain mixtures of ultradepleted peridotite and recycled crustal material. In this case a portion of the subducted sediment is not returned to the convecting mantle, but becomes stored within the subcontinental lithospheric mantle.11 page(s

Petrological characterization of the mantle source of Mediterranean lamproites : indications from major and trace elements of phlogopite

Lamproites are among the most enigmatic mantle generated melts, and are typically abundant in phlogopite. We investigated the major and trace element chemistry of phlogopite crystals from Mediterranean lamproite occurrences in Spain, Serbia and Turkey. The most primitive lamproite samples were selected in order to evaluate the generation of the different phlogopite populations in their distinct mantle setting(s). Phlogopite hosted in Mediterranean lamproites can be grouped into different compositional arrays on the basis of their major element chemistry using Al₂O₃, FeOT and TiO₂ concentrations. Contents of Cr, F and presumably Ti allow discrimination of the macrocrysts into phlogopite phenocrysts, which are liquidus and near-liquidus phases, and mantle xenocrysts. Further distinction among different populations of mantle-derived phlogopite can be achieved, considering trace element and isotopic ratios. The latter also distinguish between crustal and asthenospheric imprints on the source of the lamproitic parental melt.13 page(s

Scoring system development for prediction of extravesical bladder cancer

Background/Aim. Staging of bladder cancer is crucial for optimal management of the disease. However, clinical staging is not perfectly accurate. The aim of this study was to derive a simple scoring system in prediction of pathological advanced muscle-invasive bladder cancer (MIBC). Methods. Logistic regression and bootstrap methods were used to create an integer score for estimating the risk in prediction of pathological advanced MIBC using precystectomy clinicopathological data: demographic, initial transurethral resection (TUR) [grade, stage, multiplicity of tumors, lymphovascular invasion (LVI)], hydronephrosis, abdominal and pelvic CT radiography (size of the tumor, tumor base width), and pathological stage after radical cystectomy (RC). Advanced MIBC in surgical specimen was defined as pT3-4 tumor. Receiving operating characteristic (ROC) curve quantified the area under curve (AUC) as predictive accuracy. Clinical usefulness was assessed by using decision curve analysis. Results. This single-center retrospective study included 233 adult patients with BC undergoing RC at the Military Medical Academy, Belgrade. Organ confined disease was observed in 101 (43.3%) patients, and 132 (56.7%) had advanced MIBC. In multivariable analysis, 3 risk factors most strongly associated with advanced MIBC: grade of initial TUR [odds ratio (OR) = 4.7], LVI (OR = 2), and hydronephrosis (OR = 3.9). The resultant total possible score ranged from 0 to 15, with the cut-off value of > 8 points, the AUC was 0.795, showing good discriminatory ability. The model showed excellent calibration. Decision curve analysis showed a net benefit across all threshold probabilities and clinical usefulness of the model. Conclusion. We developed a unique scoring system which could assist in predicting advanced MIBC in patients before RC. The scoring system showed good performance characteristics and introducing of such a tool into daily clinical decision-making may lead to more appropriate integration of perioperative chemotherapy. Clinical value of this model needs to be further assessed in external validation cohorts. [Projekat Ministarstva nauke Republike Srbije, br. N0175014

The role of syn-extensional lamprophyre magmatism in crustal dynamics – the case of the Menderes metamorphic core complex, western Turkey

This work was supported through the Inneruniversitäre Forschungsförderung, University of Mainz, and Serbian Ministry of Education, Science and Technological Development, Grant/Award Number: 176016. This is FIERCE contribution No. 96.The Menderes Massif in Turkey represents one of the largest metamorphic core complexes in the world. It is regarded as a section of lower continental crust exhumed along low-angle detachment faults in the Late Miocene during a period of extension that affected the entire Aegean province. Syn-extensional magmatic activity within the Menderes metamorphic core complex is predominantly felsic forming several plutons, whereas mantle-derived magmatism has not been known so far. Here, we present a detailed study of the petrology and geochemistry of previously unreported mafic to intermediate lamprophyres within the Menderes Massif and assess their role in the geodynamic evolution of the core complex.PostprintPeer reviewe

Temporal–spatial evolution of low-SiO2 volcanism in the Pleistocene West Eifel volcanic field (West Germany) and relationship to upwelling asthenosphere

International audienc

Initiation of abnormal grain growth in cold-rolled sheet of AA5182 Al-Mg alloy: role of texture

In this work, we investigate the role of crystallographic texture on the onset of abnormal grain growth (AGG) in AA5182 alloy. TMP included 65% cold-rolling reduction and isothermal annealing at 480°C at various times. The microstructure characterization by optical microscopy in polarized light revealed that AGG starts after holding for 5 min at 480°C. Further investigation of the sample with incipient abnormal grains was conducted by an SEM equipped with an EBSD detector. The incipient abnormal grains appear to have an orientation of minor texture components, i.e. different cube variants, most likely due to the enhanced grain boundary mobility. However, texture fails to explain the difference in the propensity toward AGG in the region close to the sheet surface and its center, which is likely caused by the non-uniform distribution of the intermetallic particles

Two-Stage Origin of K-Enrichment in Ultrapotassic Magmatism Simulated by Melting of Experimentally Metasomatized Mantle

The generation of strongly potassic melts in the mantle requires the presence of phlogopite in the melting assemblage, while isotopic and trace element analyses of ultrapotassic rocks frequently indicate the involvement of subducted crustal lithologies in the source. However, phlogopite-free experiments that focus on melting of sedimentary rocks and subsequent hybridization with mantle rocks at pressures of 1–3 GPa have not successfully produced melts with K2O >5 wt%–6 wt%, while ultrapotassic igneous rocks reach up to 12 wt% K2O. Accordingly, a two-stage process that enriches K2O and increases K/Na in intermediary assemblages in the source prior to ultrapotassic magmatism seems likely. Here, we simulate this two-stage formation of ultrapotassic magmas using an experimental approach that involves re-melting of parts of an experimental product in a second experiment. In the first stage, reaction experiments containing layered sediment and dunite produced a modally metasomatized reaction zone at the border of a depleted peridotite. For the second-stage experiment, the metasomatized dunite was separated from the residue of the sedimentary rock and transferred to a smaller capsule, and melts were produced with 8 wt%–8.5 wt% K2O and K/Na of 6–7. This is the first time that extremely K-enriched ultrapotassic melts have been generated experimentally from sediments at low pressure applicable to a post-collisional setting

New insights on the geochemical affinity and age of mineralized rocks in Timok magmatic complex, East Serbia

Bor and Čukaru Peki are world-class porphyry deposits spatially and genetically associated with the Cretaceous Timok magmatic complex. This research was conducted to determine the age and geochemical affinity of the magmatic rocks that formed these ore deposits. Our new geochemical analyses of magmatic rocks from Bor and Čukaru Peki deposits imply they comprise adakite-like compositions that have undergone the amphibole fractionation and sulphide saturation processes. The zircon ages indicate that the Bor system was formed in the age span between 84.5-82 Ma, while the Čukaru Peki system was created in the age span between 86.5-85 Ma.ISSN:0350-0608ISSN:2406-074