Search

Although Middle Paleolithic (MP) hominin diets consisted mainly of ungulates, increasing evidence demonstrates that hominins at least occasionally consumed tortoises, birds, leporids, fish, and carnivores. Until now, the MP zooarchaeological record in the Zagros Mountains has been almost exclusively restricted to ungulates. The narrow range of hominin prey may reflect socioeconomic decisions and/or environmental constraints, but could also result from a research bias favoring the study of large prey, since archaeologists have undertaken no systematic taphonomic analyses of small game or carnivores in the region. Here, we report on the first comprehensive taphonomic analysis of an MP faunal assemblage from Ghar-e Boof (∼ 81–45 kyr), a Late Pleistocene site in the southern Zagros of Iran. Anthropogenic bone surface modifications point to hominins as the main agent of accumulation. Hominins preyed primarily on ungulates, particularly wild goat. However, we also found evidence for MP hominin exploitation of carnivores and tortoises at the site. Although small game represents only a minor portion of the diet, our results suggest that the hunting behavior of MP hominins in the Zagros was more diverse than previously thought, similar to what we find elsewhere in Eurasia. [ABSTRACT FROM AUTHOR]

At geostrategic level, the Caspian region is an area with significant events on the axes of Central Asia, Caucasus and India, which explains why the Soviet Union intensified its splayed dominance in the Caspian region and blocked any intervention of other countries during the Cold War. The aim of this paper is to investigate the geopolitical dimensions of Iran in the Caspian-Central Asia and how Iran's foreign relations can be influenced by its geopolitical position. The Caspian-Central Asia region is the place of living of over 50 ethnic and linguistic groups, representing the three great religions of Judaism, Islamism and Christianity. The Caspian-Central Asia or South Caspian-Central Asia, situated at the crossroads of Eurasia's major energy and transport corridors, continues to play a vital role in world's security affairs. The methodology of this research is descriptive-analytical, and it attempts to give a geopolitical answer to the question: how can Iran gain hegemony in the Caspian-Central Asia region? In accordance with the results of this paper, it seems that the geopolitical reality provides the most advantageous strategy to Iran. [ABSTRACT FROM AUTHOR]

This paper aims to understand the cultural diversity among the first modern human populations in the Iranian Zagros and the implications of this diversity for evolutionary and ecological models of human dispersal through Eurasia. We use quantitative data and technotypological attributes combined with physiogeographic information to assess if the Zagros Upper Paleolithic (UP) developed locally from the Middle Paleolithic (MP), as well as to contextualize the variation in lithics from four UP sites of Warwasi, Yafteh, Pasangar, and Ghār-e Boof. Our results demonstrate (1) that the Zagros UP industries are intrusive to the region, and (2) that there is significant cultural diversity in the early UP across different Zagros habitat areas, and that this diversity clusters in at least three groups. We interpret this variation as parallel developments after the initial occupation of the region shaped by the relative geotopographical isolation of different areas of the Zagros, which would have favored different ecological adaptations. The greater similarity of lithic traditions and modes of production observed in the later phases of the UP across all sites indicates a marked increase in inter-group contact throughout the West-Central Zagros mountain chain. Based on the chronological and geographical patterns of Zagros UP variability, we propose a model of an initial colonization phase leading to the emergence of distinct local traditions, followed by a long phase of limited contact among these first UP groups. This has important implications for the origins of biological and cultural diversity in the early phases of modern human colonization of Eurasia. We suggest that the mountainous arc that extends from Anatolia to the Southern Zagros preserves the archaeological record of different population trajectories. Among them, by 40 ka, some would have been transient, whereas others would have left no living descendants. However, some would have led to longer term local traditions, including groups who share ancestry with modern Europeans and modern East/Southeast Asians. [ABSTRACT FROM AUTHOR]

Background: Apple stem grooving virus (ASGV) has a wide host range, notably including apples, pears, prunes and citrus. It is found worldwide. Method: In this study, two near complete genomes, and seven coat protein (CP) sequences of Iranian isolates from apple were determined. Sequences added from GenBank provided alignments of 120 genomic sequences (54 of which were recombinant), and 276 coat protein genes (none of them recombinant). Result: The non-recombinant genomes gave a well supported phylogeny with isolates from diverse hosts in China forming the base of the phylogeny, and a monophyletic clade of at least seven clusters of isolates from around the world with no host or provenace groupings among them, and all but one including isolates from China. The six regions of the ASGV genome (five in one frame, one − 2 overlapping) gave significantly correlated phylogenies, but individually had less statistical support. The largest cluster of isolates contained those from Iran and had isolates with worldwide provenances, and came from a wide range of mono- and dicotyledonous hosts. Population genetic comparisons of the six regions of the ASGV genome showed that four were under strong negative selection, but two of unknown function were under positive selection. Conclusion: ASGV most likely originated and spread in East Asia in one or more of various plant species, but not in Eurasia; the ASGV population of China had the greatest overall nucleotide diversity and largest number of segregating sites. [ABSTRACT FROM AUTHOR]

Regional convergence in Eurasia has been evolving since the collapse of the Soviet Union. The Commonwealth of Independent States was Russia's initial attempt to forge a comprehensive regional integration. However, Russia gradually shifted its focus to economics, and this produced the Eurasian Economic Union (EEU). This organization has concluded numerous cooperation agreements, even with countries outside the borders of Eurasia, raising questions about regional convergence. In addition, with the expansion of China's influence in Central Asia, there has been a shift in the role and scope of the EEU. Iran has concluded a preferential trade agreement with the EEU, including non‐tariff measures and a list of commodities for which barriers have been reduced or cut to zero. The main question of this study is how Iran's presence in this organization will influence Eurasian convergence. We examine the opportunities for, and obstacles to, convergence through an analysis of the forces that can bind an institution like the EEU: cultural and ideological affinities; the hegemony of the most powerful actors; and the potential for solving common problems. [ABSTRACT FROM AUTHOR]

The interpretation of low-temperature thermochronology (LTT) data in magmatic and metallogenic provinces requires a knowledge of the geothermal field through time. There, the challenge is differentiating rapid cooling following transient perturbations of the geotherms (reheating) from exhumational cooling induced by erosion during tectonic uplift or normal faulting. The Takab Range Complex (NW Iran) is a basement-cored range of the Arabia-Eurasia collision zone that experienced voluminous Eocene to Miocene magmatism and mineralization. Our new apatite and zircon (U-Th-Sm)/He and apatite fission track data, together with field observations, a dedicated numerical thermal model, and a re-evaluation of available geochronology data document the occurrence of a complex geological and thermal history including: (a) late Cretaceous-Paleocene exhumation possibly controlled by regional contractional deformation followed by Eocene deposition; (b) Oligocene to possibly early Miocene (29 to 22-20 Ma) exhumation of basement rocks from 13 to 8 km of depth, most likely through normal faulting during a thermal anomaly that led to migmatization and partial melting; (c) early to late Miocene (~22-20 or earlier to 11-10 Ma) regional subsidence with deposition of an up to ~2- to 3-km-thick Oligo-Miocene sedimentary sequence in association with the emplacement of shallow intrusions, which led to a partial to total reset of our LTT systems sometime between 18 and 13 Ma; and (e) erosional exhumation after 11-10 Ma with the development of a transpressional system and a master, right-lateral, strike slip fault (Chahartagh Fault). Our data highlights the impact of magmatic reheating on LTT ages in areas affected by intense magmatism. [ABSTRACT FROM AUTHOR]

The Main Köpetdag Fault (MKDF) is a predominantly right-lateral strike-slip fault that dissects the northern edge of the Köpetdag mountains of Turkmenistan and Iran. The fault represents the northernmost expression of deformation from the Arabia–Eurasia collision to the east of the Caspian Sea, and plays an important role facilitating the motion of the South Caspian Basin (SCB). Despite the kinematic significance of the MKDF, previous geodetic measurements of the slip-rate across the fault have been highly variable, with a recent geological slip-rate supporting evidence for rapid motion across the fault. To resolve this ambiguity, we derive Sentinel-1 InSAR time-series in both the ascending and descending LOS (line-of-sight) to measure interseismic motion across the MKDF. This implements a processing strategy for the correction and performance analysis of tropospheric models from GACOS (Generic Atmospheric Correction Online Service), which suggests a 25–40 per cent underestimation in the amplitude of the tropospheric path delay in this region. Modelling the rate of fault-parallel motion across the MKDF and combining this with a geological slip-rate constrains 9 ± 2 mm yr–1 right-lateral motion, along with a shallow locking depth of ≈6 km. The LOS time-series resolves path delays of greater than 1 mm yr–1 in both LOS geometries to the north of the MKDF, aligned with mapped frontal thrust scarps to the north of the MKDF. Modelling this as uplift from deformation across these frontal thrusts estimates 4 ± 2 mm yr–1 of shortening across the fault system. This implies that convergence measured with GNSS within the East Caspian Lowlands is partitioned across frontal thrusts to the north of the MKDF. Revising an Iran–Eurasia–SCB velocity triangle suggests that motion along the conjugate MKDF and Shahroud fault zones is representative of the motion of the SCB, which is moving at 10 ± 2 mm yr–1 in a direction of 330° ± 10° relative to Eurasia. [ABSTRACT FROM AUTHOR]

The Aghdarband Basin in the Kopeh-Dagh Range (NE Iran) is one of the most important areas for unraveling the evolution of the Turan plate (southern margin of Eurasia) during the last phase of the closure of the Paleotethys and to reconstruct the history of the Cimmerian blocks just before their collision with Eurasia during the early Late Triassic. The youngest sediments affected by the Early Cimmerian orogeny are those of the Upper Triassic Miankuhi Formation, which covers unconformably the Upper Triassic (lower Carnian) marine beds of the Sina Formation by an interval of continental facies including local conglomerates, cross-bedded sandstones, mudstone layers, silty shales, an up to one-meter thick coal layer with plant remains, and shales. The plant assemblages represent a relatively wide variety of different forms (sphenophytes, ginkgophytes, conifers, and incertis sedis), documenting wetlands with lush vegetation typical of warm and humid environments. In this study, we describe a plant fossil assemblage from the base of the Miankuhi Fm., dominated by roots and vegetative organs of Neocalamites iranensis n. sp., with few plant fossils of uncertain botanical affinity. Palynological investigations of the basal part of the Miankuhi Formation confirm a latest early Carnian to late Carnian age for this interval and reveal, for the first time, a clear link between this plant-bearing bed, and a time of global environmental changes, the Carnian Pluvial Episode. This is the first report of the Carnian Pluvial Episode in the Turan plate (southern margin of Eurasia) and Iran. [ABSTRACT FROM AUTHOR]

We calculate seismic velocity structure of the north Zagros suture zone, west Iran, to resolve the crustal features at the boundary of Arabian‐Central Iranian collision. We compute teleseismic receiver functions (RFs) for 46 stations along a transect crossing the suture. Through harmonic analysis and inversion of the RF data, we obtain information on the characteristics of the suture zone at depth. The RFs and their harmonics show a low angle NE dipping boundary between the overriding layer and a midcrustal low velocity zone, which corresponds to the suture zone. The overriding high velocity feature (Vs ~ 3.8 km/s) is interpreted as an intermediate depth crustal complex exhumed close to the surface through imbricate thrust faulting and enhanced by crustal buoyancy due to continental underthrusting. Significant anisotropy is found above and below the suture zone: We interpret it in terms of slow‐symmetry‐axis anisotropy and derive clues on the ongoing deformation processes. Key Points: We confirmed existence of a weak shear zone in the suture between Arabian plate and the Eurasia in western ZagrosOverriding crust exhumed close to the surface through imbricate thrust faulting and enhanced by crustal buoyancyRock foliation and fluid or melt filled fractures formed during the shearing are potential source of anisotropy in both side of the suture [ABSTRACT FROM AUTHOR]

The 2017 April 5 M w 6 Sefid Sang earthquake occurred east-northeast of the town of Fariman between the Binalud Mountains, at the northeast boundary of the Arabia-Eurasia collision zone, and the Doruneh Fault which defines the northern limit of the Lut Block. The pattern of present-day deformation in this area is not well understood. We combine results from studies of earthquake location, focal mechanism solutions and Interferometric Synthetic Aperture Radar (InSAR) to investigate the coseismic displacements. The active deformation of the source region is investigated through a synthesis of the structural geology, complimented by geological fieldwork. Our results reveal that the mainshock nucleated at a depth of ∼15 km on a reverse fault plane dipping north-northeast, with a component of dextral faulting. Rupture in the mainshock was almost unidirectional towards the southeast. The temporal growth of the 24-km long aftershock cloud reflects migration of seismicity towards the southeast. Analysis of ascending and descending interferograms of TOPS S1 SAR images show a maximum of 9 and 11 cm of surface deformation, respectively. A rupture model based on the inversion of the InSAR interferograms features a maximum slip of 83 cm on the NNE-dipping fault plane. Inversion of fault-slip data from earthquake focal mechanisms and geological field measurements indicates a contemporary regional transpressional tectonic regime characterized by a NE-trending maximum compression (mean direction of N020°E for seismological slip data and N029°E for geological fault kinematics). This implies a transpressional active kinematics according to which the Central Iran–Eurasia convergence is taken up by reverse dextral faulting on several NW-striking faults such as the eastern termination of the Doruneh fault and the southeast termination of the Chakaneh-Neyshabur fault systems. Our seismological, geodetic and geological results consistently indicate accommodation of active deformation by oblique-slip reverse faulting that is distributed in the region connecting the distinct block-bounding fault systems of northeast and eastern Iran. We propose a transpressional relay zone structural model to explain the nature, kinematics and structural pattern of the boundary of the collision zone between the Doruneh Fault and the Binalud Mountains. Our observations and results could shed light on structural aspects of other intracontinental collision zone boundaries, where deformation is taken up by discontinuous continental block boundaries. [ABSTRACT FROM AUTHOR]

The Zagros Orogen formed during the Cenozoic collision of Arabia with Eurasia and resulted in the closure of the Neo‐Tethys Ocean. Collision was preceded by a complicated tectonic history involving Pan‐African orogenesis, Late Palaeozoic rifting and the formation of Neo‐Tethys, and subsequent Mesozoic convergence on the northern margin of the ocean contemporaneous with ophiolite obduction on its southern margin. The Sanandaj–Sirjan Zone (SaSZ) is a metamorphic belt within the Zagros Orogen of Gondwanan provenance. U–Pb zircon geochronology has revealed the presence of Pan‐African igneous and metamorphic basement complexes, in addition to minor late Palaeozoic plutons and abundant Jurassic plutonic rocks. This study presents a LA‐ICP‐MS U–Pb apatite age of 440.7 ± 3.7 Ma from a gabbroic body on the central north‐eastern margin of the SaSZ (Nodoushan region). Based on petrography and geochemistry, en route fractional crystallization of ascending magma was an important process in the evolution of the intrusive rocks. Geochemical characteristics imply that the south‐west Nodoushan alkaline gabbroic magma was originated from the asthenospheric mantle source, whereas the high ratios of (La/Yb)N and (Dy/Yb)N are related to the low degree of partial melting from the garnet‐bearing mantle source. Enrichment pattern of Nb, Ta, and Ti and depletion of Rb, Th, and Y are similar to the OIB pattern and intraplate alkaline magmatic rocks. High εNd(t) values (+1.29 to +1.50), low initial Sr isotopic ratios (0.703679–0.704098), and trace element ratios (e.g., Nb/La, Ce/Pb, Ba/Nb, and Th/Nb) indicate that crustal contamination was insignificant in its petrogenesis. The petrogenesis of the Nodoushan alkaline gabbroic rocks could be related to the presence of extensional phase, upwelling and decompressional melting of asthenospheric mantle in the rift basin which was associated with the opening of the Paleo‐Tethys Ocean in Late Ordovician to Silurian times. [ABSTRACT FROM AUTHOR]

We applied a nonlinear teleseismic tomography algorithm to explore the 3-D structure of the upper mantle beneath the Arabia–Eurasia continental collision zone in western Iran. An unprecedented data set consisting of 32 738 teleseismic P- wave relative arrival time residuals from 129 permanent and temporary seismic stations was inverted for seismic imaging. The seismic images suggest a thick high-velocity lithospheric mantle beneath the Zagros. Other high-velocity domain observed below ∼300 km depth, which is not connected to the Zagros lithosphere, is interpreted as a slab segment in the upper mantle beneath the collision zone. The low-velocity anomalies beneath Central Iran and Alborz, consistent with a weak upper mantle, may be a result of upwelling asthenosphere and partial melting of the subducted lithosphere. [ABSTRACT FROM AUTHOR]

A better understanding of intraplate deformation requires the knowledge of the space–time scales involved in its development and to decipher possible links with the dynamic evolution of the plate boundaries. Central Iran provides an ideal test site to approach this scientific issue, since it is characterised by a prolonged history of Mesozoic–Cenozoic intraplate deformation that has been interfering with the spatio‐temporal re‐organization of the Zagros convergence zone along the Eurasia plate boundary. This study focus on the Doruneh Fault (DF) region that is considered as the northern mechanical boundary of the Central East Iranian Microcontinent. By combining field investigations with apatite low‐temperature thermochronology, we present a revised tectono‐stratigraphic scenario for the DF region, typified by a punctuated history of fault‐related exhumation, burial and cooling history back to the Upper Cretaceous. When framed at regional scale, these results attest that the Zagros convergence zone, and its hinterland domain were fully mechanically coupled since ca. 40–35 Ma, a time lapse that is here referred as to the onset of continental collision along the Arabia–Eurasia plate boundary. In this scenario, the DF region operated throughout the Cenozoic as a major zone of residual stress accommodation and transfer in the hinterland domain of the Zagros convergence zone. Results of this study also suggest that the tectonic evolution along the Arabia–Eurasia plate boundary was modulated by the plate‐boundary dynamics and by the modes of tectonic reactivation of the intracontinental weak zones of Central Iran and at its tectonic boundaries. [ABSTRACT FROM AUTHOR]