Post-collisional polycyclic plutonism from the Zagros hinterland: the Shaivar Dagh plutonic complex, Alborz belt, Iran

The petrological and geochronological study of the Cenozoic Shaivar Dagh composite intrusion in the Alborz Mountain belt (NW Iran) reveals important clues to decipher complex relations between magmatic and tectonic processes in the central sectors of the Tethyan (Alpine-Himalayan) orogenic belt. This pluton is formed by intrusion at different times of two main magmatic cycles. The older (Cycle 1) is formed by calc-alkaline silicic rocks, which range in composition from diorites to granodiorites and biotite granites, with abundant mafic microgranular enclaves. The younger cycle (Cycle 2) is formed by K-rich monzodiorite and monzonite of marked shoshonitic affinity. The latter form the larger volumes of the exposed plutonic rocks in the studied complex. Zircon geochronology (laser ablation ICP-MS analyses) gives a concordia age of 30.8 ± 2.1 Ma for the calc-alkaline rocks (Cycle 1) and a range from 23.3 ± 0.5 to 25.1 ± 0.9 Ma for the shoshonitic association (Cycle 2). Major and trace element relations strongly support distinct origins for each magmatic cycle. Rocks of Cycle 1 have all the characteristic features of active continental margins. Shoshonitic rocks (Cycle 2) define two continuous fractionation trends: one departing from a K-rich basaltic composition and the other from an intermediate, K-rich composition. A metasomatized-mantle origin for the two shoshonitic series of Cycle 2 is proposed on the basis of comparisons with experimental data. The origin of the calc-alkaline series is more controversial but it can be attributed to processes in the suprasubduction mantle wedge related to the incorporation of subducted mélanges in the form of silicic cold plumes. A time sequence can be established for the processes responsible of the generation of the two magmatic cycles: first a calc-alkaline cycle typical of active continental margins, and second a K-rich cycle formed by monzonites and monzodiorites. This sequence precludes the younger potassic magmas as precursors of the older calc-alkaline series. By contrast, the older calc-alkaline magmas may represent the metasomatic agents that modified the mantle wedge during the last stages of subduction and cooked a fertile mantle region for late potassic magmatism after continental collisio

A mobile and intelligent device for customized logopedic therapy

An expert system for customized logopedic therapy must allow the training of children depending on its speech disabilities and former progress. The children’s training is accomplished using exercises chosen by the expert system and can be performed either in the doctor’s office or at home for each child using an intelligent mobile device. The expert system generates a set of exercises for each child depending on the doctor’s recommendation. These exercises are transferred from PC to mobile devices using a Universal Serial Bus connection. The mobile device saves the result of each therapy session and when it is connected to PC it transfers the results to the expert system for analysis. Using the results of these analyses the expert system will decided whether a new session is needed and if that is the case, compute a new set of exercises

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

Magmatic evolution and porphyry–epithermal mineralization in the Taftan volcanic complex, southeastern Iran

The Taftan volcanic complex is located above the Makran subduction zone in Sistan and Baluchestan province, southeastern Iran. The earliest volcanic activity at Taftan started in the late Miocene (~8 Ma) with eruption of andesitic to dacitic lava onto a Cretaceous to Eocene volcanic and sedimentary paleosurface ~20 km to the northwest of the current volcanic edifice. Later Plio-Pleistocene volcanism consisted of voluminous andesitic and dacitic lavas and pyroclastic flows (~3.1 to 0.4 Ma). Taftan, and the neighbouring Bazman volcano, are the southeasternmost and youngest manifestations of arc-related volcanism in Iran, which began with the Eocene–Miocene Urumieh-Dokhtar Magmatic Arc (UDMA) in northwest and central Iran, and extends into western Pakistan (Chagai Arc). Major porphyry Cu±Mo±Au deposits are associated with Miocene to Pliocene intrusive rocks in the Kerman section of the Eocene–Neogene Urumieh-Dokhtar Magmatic Arc in southeastern Iran (e.g., Sar Cheshmeh, Meiduk), and at Reko Diq and Saindak in the Late Cretaceous–Quaternary Chagai Arc in western Pakistan. In a gap of ~300 km between these two belts, several porphyry and epithermal prospects are exposed in the Miocene–Pliocene sections of the Taftan volcanic complex, including the Kharestan (6.10 ± 0.80 Ma) and Bidester porphyry-epithermal Cu-Au deposits (~4.3 Ma), and the Siah Jangal epithermal Au deposit (late Miocene). In addition, several argillic to advanced argillic and fumarolic alteration zones occur in Plio-Pleistocene volcanic rocks around the current volcanic edifice. These deposits have received limited exploration. Electron microprobe analyses of amphibole (magnesio-hastingsite) phenocrysts and magnetite–ilmenite mineral pairs from the Taftan and Bazman volcanic rocks indicate a change of crystallization temperature and magmatic oxidation state from ~1000°C and FMQ ≈ +1 in andesitic rocks, to ~900°C and FMQ ≈ +2 in dacitic rocks. Magmatic water content was >4 wt.%, as indicated by the ubiquitous presence of amphibole phenocrysts. Major and trace element compositions of the Taftan and Bazman volcanic rocks show calc-alkaline to high-K calc-alkaline affinity, with relative depletions of Nb, Ta, and Ti and enrichments of large-ion lithophile elements (LILE), Th, and U on normalized diagrams. These trace element patterns, including listric-shaped normalized rare earth element profiles and relatively high Sr/Y and La/Yb ratios, are similar to those of fertile Miocene igneous rocks from the Kerman Belt and Chagai Arc, and suggest that the Taftan suite in particular should be prospective for porphyry Cu ore formation. Regionally, there is no clear geochemical difference between the Neogene Kerman Belt rocks, which are thought to post-date the onset of collision between the Afro-Arabian and Eurasian plates (late Oligocene to earliest Miocene), and the subduction-related Bazman– Taftan and Chagai Belt magmas. The porphyry deposits formed in these distinct settings are also virtually indistinguishable. This suggests that most of the processes affecting the geochemistry and metallogeny of the magmas in both settings take place in the lithosphere, albeit that the ultimate source of the magmas is in the supra-subduction zone asthenospheric mantle wedge. In collisional environments, subduction-related material previously crystallized in the deep lithosphere is simply being remobilized

Geochemistry and petrogenesis of Cretaceous volcanic rocks from the south and southwest of Germi city (Northwest of Iran)

The Cretaceous volcanic rocks (Andesite and basaltic andesite) in the northwest of Iran, south - southwest of the Germi city (Ardabil province), have considerable outcrops with northwest - southeast trend. The textures in the studied rocks are porphyry, hyalomicrolitic and glomeroporphyry and the main mineral is plagioclase with pyroxene, brown amphibole and biotite as accessory minerals. The rocks under study have calc-alkaline nature and have been crystallized from a magma experienced fractional crystallization. In the primitive mantle normalized spider and chonderite normalized rare earth elements diagrams. The studied rocks are characterized by LREE and LILE enrichment and depletion in HFSE as well as spikes in Pb and Eu. The overall features are compatible with subduction-related. The Cretaceous volcanic rocks under study have been generated in an active continental margin

Bulanık ve fraktal modelleme kullanılarak Sonajeel sahasında (KB İran) porfiri bakır prospeksiyon haritalaması

Bu çalışmanın temel amacı, yerel ölçekte Coğrafi Bilgi Sistemleri (CBS) temelli olasılık modeli kullanarak porfiri cevherleşme olasılığını ortaya koymak ve oluşturulan modelin geçerliliğini saha gözlemleri, yüzey örneklemesi ve sondaj verileriyle değerlendirmektir. Bu çalışmada konu edilen Sonajeel sahası, KB İran’da Arabasaran cevherleşme kuşağının bir parçasını oluşturmaktadır. Bir cevherleşme tipi ile ilgili matematiksel arama algoritması oluşturmak, karmaşık ve disiplinler arası bir çalışmadır. Bu amaçla, bu çalışmada jeoloji, jeokimya ve uzaktan algılama çalışmalarını da içeren farklı veri setlerinin işlenmesi ve yorumlanmasından elde edilen sonuçlar göz önünde bulundurulmuştur. Sillitoe (2010) tarafından önerilen aramaaşaması ve tanımlayıcı porfir cevherleşme modeli göz önünde bulundurularak kapsamlı bir arama bütünleştirme modeli oluşturulmuştur. CBS tabanlı arama modeline ait girdileri düzenlemek için bulanık üye eğrileri kullanarak değer atanmış gridler (ızgaralar) veya kanıt katmanları üretilmiş ve daha sonrasında da gama bulanık fonksiyonu ile birleştirilmiştir. Buna ek olarak, maden prospeksiyon haritasının tanımlanması ve bulanıklığının giderilmesi için olasılık haritasının piksel değerleri üzerinde Konsantrasyon-Alan (C-A) fraktal modeli uygulanmıştır. Son olarak sonuçlar, saha gözlemleri, yüzey örneklemesi ve sondaj verileri ile doğrulanmıştır. İlk öncelik olarak sondaj logları ortalama %0.5 Cu tenörlü bir zonu ortaya koymuştur

Jurassic granitoids in the northwestern Sanandaj Sirjan Zone: Evolving magmatism in response to the development of a Neo-Tethyan slab window

Voluminous Jurassic granitoids within the Sanandaj-Sirjan Zone (SSZ) provide insight into the magmatic arc formed in the active margin of Eurasia. Here, we present new in situ zircon U-Pb, whole-rock major and trace element, and Sr-Nd isotopic data for the Gorveh Plutonic Complex (GPC) of the northwestern SSZ in Iran. Six samples from the plutons within the GPC yielded zircon U-Pb ages that range from 151 to 146 Ma. These plutons can be subdivided into two groups based on their geochemistry. Group 1 rocks (the Mobarak Abad diorites and the Gorveh gabbros and diorites) contain relatively high concentrations of the high field strength elements (HFSE; Nb, Ta, Zr, and Ti) and have low Th/Nb (0.20-0.56) and moderate Sm/Yb ratios (1.51-2.32), low (87Sr/86Sr), values (0.70354-0.70622), and high ENd(t) values (2.3-5.4). These features indicate that the Group 1 rocks formed from magmas derived from a subduction-modified region of the subcontinental lithospheric mantle. The Group 2 plutons (the Bolban Abad granites and the Gorveh quartz monzonites) have A-type granites affinities, including high K20-I- Na20 and Zr + Nb + Ce + Y concentrations, and high Fe0'/Mg0 and 10,000 x Ga/AI ratios. These A-type rocks are enriched in Rb, Th, and K, and depleted in Ba, U, Nb, Ta, Sr, P, and Ti. The Group 2 plutons have different Sr-Nd isotopic compositions to each other, indicating they were derived from different sources and record different igneous processes. The Gorveh quartz monzonites have high ("Sr/86Sr); ratios (0.70552-0.70617), negative ENd(t) values ( 1.1 to 5.4), and extremely low concentrations of Mg0 (0.32-0.35 wt%), suggesting they were derived from an igneous quartzo-feldspathic crustal source. In comparison, the Bolban Abad granites have positive ENd(t) values and contain high concentrations of Si02 and low concentrations of MgO, suggesting that they formed from Group 1 magmas that subsequently underwent assimilation and fractional crystallization processes. Combining these new data with the results of previous research, we conclude that this Jurassic magmatism was the result of the formation of a slab window within the subducting Neo-Tethys slab, a process that caused the partial melting of overlying continental lithospheric material. (C) 2018 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved