20 research outputs found

    Zircon U-Pb geochronology and emplacement history of intrusive rocks in the Ardestan section, central Iran

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    The Urumieh-Dokhtar Magmatic Arc (UDMA) is part of the Alpine–Himalayan orogenic belt and interpreted to be a subduction-related Andean-type magmatic arc. Along this belt, Eocene volcanics and some gabbroic to granitic bodies crop out. The main rock types of the studied intrusion are granite, granodiorite, and diorite. They have geochemical features typical of magnesian, calc-alkaline, metaluminous to slightly peraluminous granites and I-type intrusive rock that have a strong enrichment in Large-Ion Lithophile (LIL) elements (e.g. Rb, Ba, Sr), and a depletion in High Field Strength (HFS) elements (e.g. Nb, Ti, P), typical of subduction-related magmas. Zircon U-Pb dating was applied to determine the emplacement ages of the different intrusions in the Ardestan area. Among them the Kuh-e Dom diorite is 53.9±0.4Ma old; the Kuh-e Dom granodiorite is 51.10±0.4Ma old; the Mehrabad granodiorite is 36.8±0.5Ma old, the Nasrand granodiorite is 36.5±0.5Ma old, the Zafarghand granodiorite is 24.6±1.0Ma old, and the Feshark granodiorite is 20.5±0.8Ma old. These results delineate more accurately the magmatic evolution related to the Neotethyan subduction from the Lower Eocene to Lower Miocene, and the subsequent Zagros orogeny that resulted from the Arabia-Eurasia collision. The emplacement of these intrusive rocks inside the UDMA, which has a close relationship with the collisional orogeny, is transitional from a subduction-related setting to post-collisional setting in the Ardestan area

    Metallogeny of Serpentinite-Hosted Magnetite Deposits : Hydrothermal Overgrowth on Chromite or Metamorphic Transformation of Chromite?

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    Peculiar and rare occurrences of serpentinite-hosted magnetite deposits with mineable sizes are found in the Mesozoic ophiolites of Greece (Skyros), Iran (Nain and Sabzevar) and Oman (Aniba). These deposits have diverse thickness (from a few centimeters up to 50 m) and length (2 to >500 m). Magnetite ores show variable textures, including massive, nodular and banded ores, veins, net and fine-grained disseminations in serpentinites. Intriguingly, the investigated magnetite deposits can be mistaken for chromitite pods. Serpentinite-hosted magnetite deposits show three modes of occurrences including: (i) boulders strewn across the serpentinites (i.e. Skyros Island) (ii) ore bodies along the nonconformity contacts between serpentinites and limestones (i.e. Aniba); (iii) irregular and discontinuous trails of massive and semi-massive ore bodies within highly sheared serpentinite masses (i.e. Nain; Sabzevar). In all of these magnetite ore bodies, relicts of chromian spinel grains are occasionally enclosed in magnetite crystals. The chemistry of Cr-spinel relics found in these magnetite bodies are comparable to those of accessory Cr-spinels in the surrounding serpentinized peridotites. BSE images and elemental mapping revealed that magnetite occurs as a nucleation on chromian spinels but not being involved in reaction either with chromite or ferritchromite. Low-grade metamorphic transformation of chromite into Fe-chromite is documented along the cracks and fractures of a few chromite grains. Generally, magnetite has typical hydrothermal compositions, characterized by low Cr, V and Ti and high Mg and Mn. It is crucial to note that a few magnetite grains with metamorphic origin are characterized by high Cr and low Ti and Ni. The potential source of iron is essentially the Fe-rich olivine, We believe that multi-episodic serpentinization of peridotite systems at high fluid-rock ratios is the main process responsible for precipitation of magnetite at ore levels whereas low-grade metamorphic transformation of chromite to magnetite has minor contribution. Cumulative factors in generation of these deposits are modal volume of mantle olivine, peridotite composition, fluid chemistry, fluid-rock ratio, mechanisms of transportation and precipitation, structural controls such as cracks and shear zones

    A compact 130GHz fully packaged point-to-point wireless system with 3D-printed 26dBi lens antenna achieving 12.5Gb/s at 1.55pJ/b/m

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    Low-cost, energy efficient, high-capacity, scalable, and easy-to-deploy point-to-point wireless links at mm-waves find a variety of applications including data intensive systems (e.g., data centers), interactive kiosks, and many emerging applications requiring data pipelines. Operating above 100GHz enables compact low-footprint system solutions that can multiplex Tb/s aggregate rates for dense deployments; therefore competing with wired solution in many aspects including rate and efficiency, but much more flexible for deployment. The focus is on small-footprint fully integrated solutions, which overcome traditional packaging challenges imposed at >100GHz with commercial and low-cost solutions.info:eu-repo/semantics/acceptedVersio

    Post-Eocene volcanic of the Abazar district, Qazvin, Iran : mineralogical and geochemical evidence for a complex magmatic evolution

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    International audienceThe style of volcanism of post-Eocene volcanism in the Alborz zone of northern Iran is different to that of Eocene volcanism (Karaj Formation). Indeed, the volcanic succession of the Abazar district, located in a narrow volcanic strip within the Alborz magmatic assemblage, is characterized by distinct mineralogical and chemical compositions linked to a complex magmatic evolution. The succession was produced by explosive eruptions followed by effusive eruptions. Two main volcanic events are recognized: (1) a thin rhyolitic ignimbritic sheet underlain by a thicker lithic breccia, and (2) lava flows including shoshonite, latite, and andesite that overlie the first event across a reddish soil horizon. Plagioclase in shoshonite (An48-92) shows normal zoning, whereas plagioclase in latite and andesite (An48-75) has a similar composition but shows reverse and oscillatory zoning. QUILF temperature calculations for shoshonites and andesites yield temperatures of 1035 °C and 1029 °C, respectively. The geothermometers proposed by Ridolfi et al. (2010) and Holland and Blundy (1994) yield temperatures of 960 °C and 944 °C for latitic lava, respectively. The samples of volcanic rock show a typical geochemical signature of the continental arc regime, but the andesites clearly differ from the shoshonites, the latites and the rhyolites. The mineralogical and chemical characteristics of these rocks are explained by the following petrogenesis: (1) intrusion of a hot, mantle-depth mafic (shoshonitic) magma, which differentiated in the magma chamber to produce a latitic and then a rhyolitic liquid; (2) rhyolitic ignimbritic eruptions from the top of the magma chamber, following by shoshonitic and then latitic extrusions; (3) magma mingling between the latitic and andesitic magmas, as indicated by the occurrence of andesite clasts within the latite; and (4) andesitic effusions. The youngest volcanic events in the Alborz zone show a close chemical relationship with continental arc rocks, indicating that they formed in a continental collision setting

    Post-Eocene volcanic of the Abazar district, Qazvin, Iran : mineralogical and geochemical evidence for a complex magmatic evolution

    No full text
    International audienceThe style of volcanism of post-Eocene volcanism in the Alborz zone of northern Iran is different to that of Eocene volcanism (Karaj Formation). Indeed, the volcanic succession of the Abazar district, located in a narrow volcanic strip within the Alborz magmatic assemblage, is characterized by distinct mineralogical and chemical compositions linked to a complex magmatic evolution. The succession was produced by explosive eruptions followed by effusive eruptions. Two main volcanic events are recognized: (1) a thin rhyolitic ignimbritic sheet underlain by a thicker lithic breccia, and (2) lava flows including shoshonite, latite, and andesite that overlie the first event across a reddish soil horizon. Plagioclase in shoshonite (An48-92) shows normal zoning, whereas plagioclase in latite and andesite (An48-75) has a similar composition but shows reverse and oscillatory zoning. QUILF temperature calculations for shoshonites and andesites yield temperatures of 1035 °C and 1029 °C, respectively. The geothermometers proposed by Ridolfi et al. (2010) and Holland and Blundy (1994) yield temperatures of 960 °C and 944 °C for latitic lava, respectively. The samples of volcanic rock show a typical geochemical signature of the continental arc regime, but the andesites clearly differ from the shoshonites, the latites and the rhyolites. The mineralogical and chemical characteristics of these rocks are explained by the following petrogenesis: (1) intrusion of a hot, mantle-depth mafic (shoshonitic) magma, which differentiated in the magma chamber to produce a latitic and then a rhyolitic liquid; (2) rhyolitic ignimbritic eruptions from the top of the magma chamber, following by shoshonitic and then latitic extrusions; (3) magma mingling between the latitic and andesitic magmas, as indicated by the occurrence of andesite clasts within the latite; and (4) andesitic effusions. The youngest volcanic events in the Alborz zone show a close chemical relationship with continental arc rocks, indicating that they formed in a continental collision setting

    Reporting Cultural Adaptation in Psychological Trials – The RECAPT criteria

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    BACKGROUND: There is a lack of empirical evidence on the level of cultural adaptation required for psychological interventions developed in Western, Educated, Industrialized, Rich, and Democratic (WEIRD) societies to be effective for the treatment of common mental disorders among culturally and ethnically diverse groups. This lack of evidence is partly due to insufficient documentation of cultural adaptation in psychological trials. Standardised documentation is needed in order to enhance empirical and meta-analytic evidence. PROCESS: A “Task force for cultural adaptation of mental health interventions for refugees” was established to harmonise and document the cultural adaptation process across several randomised controlled trials testing psychological interventions for mental health among refugee populations in Germany. Based on the collected experiences, a sub-group of the task force developed the reporting criteria presented in this paper. Thereafter, an online survey with international experts in cultural adaptation of psychological interventions was conducted, including two rounds of feedback. RESULTS: The consolidation process resulted in eleven reporting criteria to guide and document the process of cultural adaptation of psychological interventions in clinical trials. A template for documenting this process is provided. The eleven criteria are structured along A) Set-up; B) Formative research methods; C) Intervention adaptation; D) Measuring outcomes and implementation. CONCLUSIONS: Reporting on cultural adaptation more consistently in future psychological trials will hopefully improve the quality of evidence and contribute to examining the effect of cultural adaptation on treatment efficacy, feasibility, and acceptability

    On the current psychotherapeutic situation for persons with pornography use disorder in Germany

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    Background and aims: For the first time, the ICD-11 provides the diagnosis compulsive sexual behavior disorder (CSBD) that can be assigned for pornography use disorder (PUD). This study aimed to es- timate the prevalence of PUD and associated consequences in Germany, to identify the psychotherapy demand among likely PUD (lPUD) cases and the treatment supply in different psychotherapeutic settings, to survey psychotherapists’ level of expertise regarding PUD, and to identify predictors for psychotherapy demand. Methods: Four studies were conducted: 1. Online study in the general population (n 5 2070; m 5 48.9%, f 5 50.8%, d 5 0.2%), 2. Survey among practicing psychotherapists (n 5 983), 3. Survey of psychotherapists in psychotherapeutic outpatient clinics (n 5 185), 4. Interviews with psychotherapeutic inpatient clinics (n 5 28). Results: The estimated prevalence of lPUD in the online study was 4.7% and men were 6.3 times more often affected than women. Compared to individuals without PUD, individuals with lPUD more often indi- cated negative consequences in performance-related areas. Among lPUD cases, 51.2% of men and 64.3% of women were interested in a specialized PUD treatment. Psychotherapists reported 1.2%–2.9% of lPUD cases among their patients. 43.2%–61.5% of psychother- apists stated to be poorly informed about PUD. Only 7% of psy- chotherapeutic inpatient clinics provided specific treatments to patients with PUD. While, among other factors, negative conse- quences attributed to lPUD were predictive for psychotherapy demand, weekly pornography consumption, subjective well-being, and religious attachment were not. Discussion and conclusions: Although PUD occurs quite often in Germany, availability of mental health care services for PUD is poor. Specific PUD treat- ments are urgently needed

    Reporting cultural adaptation in psychological trials - The RECAPT criteria

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    Background: There is a lack of empirical evidence on the level of cultural adaptation required for psychological interventions developed in Western, Educated, Industrialized, Rich, and Democratic (WEIRD) societies to be effective for the treatment of common mental disorders among culturally and ethnically diverse groups. This lack of evidence is partly due to insufficientdocumentation of cultural adaptation in psychological trials. Standardised documentation is needed in order to enhance empirical and meta-analytic evidence. Process: A "Task force for cultural adaptation of mental health interventions for refugees" was established to harmonise and document the cultural adaptation process across several randomised controlled trials testing psychological interventions for mental health among refugee populations in Germany. Based on the collected experiences, a sub-group of the task force developed the reporting criteria presented in this paper. Thereafter, an online survey with international experts in cultural adaptation of psychological interventions was conducted, including two rounds of feedback. Results: The consolidation process resulted in eleven reporting criteria to guide and document the process of cultural adaptation of psychological interventions in clinical trials. A template for documenting this process is provided. The eleven criteria are structured along A) Set-up; B) Formative research methods; C) Intervention adaptation; D) Measuring outcomes and implementation. Conclusions: Reporting on cultural adaptation more consistently in future psychological trials will hopefully improve the quality of evidence and contribute to examining the effect of cultural adaptation on treatment efficacy,feasibility, and acceptability
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