Contribution of ultramafic rocks in central Sanandaj-Sirjan zone to the characterizing of physio-chemical condition during initiation of subduction

In the central part of the Sanandaj-Sirjan zone, there is an ultramafic rock exposure (hornblendite and pyroxenite) adjacent to Molataleb felsic complex completely located between Azna and Aligoodarz towns. The ultramafic rocks are actually cumulates derived from boninitic magma. During Upper Triassic-Lower Jurassic time the boninitic magma has been originated from mantle wedge as the result of initiation of Neo-Tethys subduction. Later, when subduction was proceeding, the felsic rocks crystallized in Middle Jurassic. Major elements composition of olivine, pyroxene, amphibole and minor plagioclase from the ultramafic rocks reveals crystallization from a sub-alkaline to calc-alkaline magma in a subduction zone setting. Primary minerals have chemical characteristics typical of those derived from a magma with low oxygen fugacity. Different methods for minerals thermobarometry indicate that amphiboles crystallized in relatively low temperature (880°C) but crystallization condition of other minerals corresponds to higher temperatures (1000-1200°c). They were crystallized at pressure condition equal to 5.85 kbar corresponding to the depth of ~17 km. It is not common that a mantle wedge at the depth of ~17 km to be affected by such high thermal gradient during the normal subduction process. Asthenospheric flow around the subducting slab edge during subduction initiation can explain high thermal gradient prevailed the infant mantle wedge. This mechanism corresponds to the boninitic nature of the ultramafic rocks

Evaluation of the pulse pressure index at the peak of exercise before and after cardiac rehabilitation

Background and Objectives: As a new supplementary therapeutic option, cardiac rehabilitation (CR) is getting more attention each day. Several studies have proved the positive impact on qualitative criteria but few studies have been done on quantitative criteria.The purpose of the survey in this study is to evaluate the impact of CR on non-invasive estimated maximum cardiac output by Pulse Pressure index (PPI) at the  peak of exercise.Methods: This is a nonrandomized prospective cohort study conducted in Hamadan, Iran in 2015.100 eligible patients who underwent coronary artery bypass surgery, based on cardiologist permission and an informed consent, participated in our study. The PPI was measured at the peak of exercise before and after standard CR program.Result: In overall, mean of PPI was not significantly different before and after CR. PPI was noticeably increased in patients younger than 60 years old (p = 0.022). In contrast to hypertensive patients, PPI in non-hypertensive patients increased significantly after CR (p=0.002). PPI considerably increased in non-diabetic patients after CR (p=0.046), but not in diabetic individuals. Other variables had not any significant effect on PPI in response to CR.Conclusion: it is clear that PPI is associated with vascular atherosclerosis, as well as cardiac output; Positive effects of CR diminish in older, diabetic and hypertensive patients with more progressive atherosclerosis

Geochemistry of microgranular enclaves in Aligoodarz Jurassic arc pluton, western Iran: implications for enclave generation by rapid crystallization of cogenetic granitoid magma

Microgranular enclaves are common in the Jurassic Aligoodarz granitoids of western Iran. Enclaves Enclosed in Granodiorite (EEG) and Enclaves Enclosed in Tonalite (EET) are different but they overlap their hosts on variation diagrams. The EEG is compositionally intermediate between tonalite and granodiorite. Mixing between tonalitic and granodioritic magmas and fractional crystallization are two models examined as the origin of the EEG. Field, textural, mineralogical and chemical observations suggest that chemical equilibration, common in magma mixing, was not attained between the EEG and its host. This, together with other observations does not support magma mixing as a mechanism for forming the EEG. Alternatively, excessive nucleation of biotite ± Fe-Ti-oxides ± amphibole by rapid cooling at borders of a shallow magma chamber and later fragmentation and dispersal by dynamic arc plutonism best explains the EEG. However, channeling of a new magma into the nearly solid tonalitic host explains formation of the EET

Geochemistry and zircon U–Pb geochronology of Aligoodarz granitoid complex, Sanandaj-Sirjan Zone, Iran

The Aligoodarz granitoid complex (AGC) is located in the Sanandaj-Sirjan Zone (SSZ), western Iran and consists of quartz-diorites, granodiorites and subordinate granites. Whole rock major and trace element data mostly define linear trends on Harker diagrams suggesting a cogenetic origin of the different rock types. (^(87)Sr/^(86)Sr)i and eNdt ratios are in the ranges 0.7074–0.7110 and -3.56 to -5.50, respectively. The trace elements and Sr–Nd isotopic composition suggest that the granitoids from the AGC are similar to crustal derived I-type granitoids of continental arcs. The whole rock suite was produced by assimilation and fractional crystallization starting from a melt with intermediate composition likely possessing a mantle component. In situ zircon U–Pb data on the granites with LA-ICP-MS yield a crystallization age of ~165 Ma. Inherited grains spanning in age from ~180 Ma up to 2027 Ma were also found and confirm that assimilation of country rock has occurred. Chemical and chronological data on the AGC were compared with those available for other granitoid complexes of the central SSZ (e.g., Dehno, Boroujerd and Alvand). The comparison reveals that in spite of the different origins that have been proposed, all these granitoid complexes are likely genetically related. They share many chemical features and are derived from crustal melts with minor differences. Alvand granites have the most peculiar compositions most likely related to the presence of abundant pelitic component. All these intrusions are coeval and reveal the presence of an extensive magmatic activity in the central sector of the SSZ during middle Jurassic