Ali Solgi's research while affiliated with Islamic Azad University Tehran Science and Research Branch and other places

The impact of a group of parallel or connected faults causes the creation of fault zones. The effect of brittle spots on the region's rocks differs, and the amount of stress in other parts of the fault varies. In addition to the different amounts of stress in other parts of the fault, the fracture rate of the rock mass in the fault area is variable in such a way that the parts that have not been deformed, in the form of blocks surrounded by severely crushed elements that create a weaker matrix and cause Inhomogeneity in the brittle fault zone, which is called bimrock. Bimrock (block-in-matrix rock) includes mélanges, fault rocks, weathered rocks, and other complex geological mixtures in strong blocks surrounded by a weaker matrix. Investigation and research on the geometry of brittle faults and the impact of these faults on the rocks of the region and establishing a relationship between the mechanism of faults and resistance characteristics is necessary. In this research, we did the geometrical analysis of the North Tehran fault and the Pourkan Verdij fault by examining fault branches and s-c structures in the fault zone. Also, the geomechanical properties of the fault rocks and Bimrocks in the area were investigated using two-dimensional analysis of the outcrop images of the fault zone by "Image Analysis" software and rock mechanics tests. As a result, the survey conducted in the cross-section of these two faults from the front side of the fault zone to the end of the fault zone showed that the volume ratio and uniaxial strength of the fault stone blocks of the North Tehran fault zone show regular changes. In such a way that as we move from the front of the site to the end of the fault zone, the amount of rock crushing decreases, and as a result, the volume ratio of the blocks and their resistance increases. While in the Porkan-Verdij fault zone, these changes are not visible in a particular order from the forehead to the end of the site, and the amount of these changes is sudden and less than in the North Tehran fault zone. This is related to the displacement rate created by the fault, the presence of micro-faults, and the distance of the shear planes relative to each other. This study can solve the most severe geotechnical problems related to rock engineering caused by brittle faults.

This paper describes five gymnospermous macro-remains, including bennettitalean (Otozamites furoni), coniferalean (Pityophyllum longifolium and Stachyotaxus septentrionalis), ginkgoalean (Sphenobaiera gyron), and czekanowskialean (Phoenicopsis speciosa) leaves, from the Jirandeh area in the western Alborz, Iran. Materials were collected from a Lower Jurassic coal-bearing horizon within the Shemshak Group in the Jirande locality. The morphological characters of encountered gymnospermous remains, together with their palaeogeographical distribution and stratigraphical occurrences, are discussed herein. The species Sphenobaiera gyron is recorded here for the first time from Asia. Pityophyllum longifolium and Stachyotaxus septentrionalis are described for the first time in Iran. This is also the first report of Phoenicopsis speciosa from the western Alborz region. The upland environment under a subtropical to warm-temperate climate is suggested for the Lower Jurassic deposits in the Jirande area based on the occurrence of the encountered gymnospermous taxa.

This paper deals with the Mesozoic seed ferns from the Shemshak Group from two localities in the Western Alborz Mountains, Northern Iran (i.e., the Abyek area in Qazvin Province and the Jirande area in Gilan Province). The materials were obtained from two coal-bearing horizons in the Shemshak Group, Late Triassic-Middle Jurassic in age. Five species from the Abyek and two species from the Jirande area, belonging to the phylum Pteridospermophyta, were identified. Vegetative and reproductive organs of Caytoniales (i.e., Sagenopteris sp. A and Sagenopteris sp. B leaves, Caytonia sp. ovuliferous organ, and Caytonanthus arberi Thomas (Harris) emend. Harris, 1964 microsporangiate organ, as well as two form-species of incertae sedis seed ferns, Pachypteris lanceolata Brongniart, 1828 and Ptilozamites tenuis Ôishi 1932 emend. Ôishi and Huzioka, 1938) are described in the present paper. This paper discusses the morphological characters of these species, together with discussions on their previous palaeobotanical descriptions, as well as the stratigraphic and palaeogeographical distribution of these taxa. This is the first record of Caytonanthus arberi in Asia and Ptilozamites tenuis from Iran. Pachypteris lanceolata is described for the first time in the Western Alborz.

The morphotectonic analysis is a useful time-saving and cost-effective method to assess tectonic activity, especially in large regions. In this paper, the morphotectonic study was carried out in Kerman city which is in the southeast of Iran and is a part of the Central Iran structural zone. Despite the occurrence of numerous historical and instrumental earthquakes around Kerman city, there is a gap in earthquake records of this city that has obscured its seismicity status. The aim of this study is to identify active faults and the associated seismic hazard to Kerman city. For this purpose, seven geomorphic indices namely stream length-gradient index (SL), drainage basin asymmetry (Af), hypsometric integral (Hi), ratio of valley-floor width to valley height (Vf), index of drainage basin shape (Bs), index of mountain front sinuosity (Smf) and Transverse Topographic Symmetry Factor (T) were examined for 51 basins of the study area, using digital elevation model (DEM) and geological maps in a GIS environment. Then, two kinds of relative tectonic activity index were calculated for each basin, i.e., Iat and Iat_T, from the combination of these indices. The Iat_T was chosen because its results show better agreement with the structural geology and seismic records of this region. Finally, the study area was divided into three regions according to the Iat_T values. The morphotectonic analyses indicate that the Kuhbanan fault system, especially its southern splays, has the potential to produce serious seismic hazards to Kerman city in the future; the Mahan-Jupar fault-related folds, the southern tip of the Jorjafk fault, the probable fault of Zangi-Abad, the Rafsanjan-Zarand fault system, and Gowk fault are considered as other threats to Kerman city. Furthermore, this study reveals that morphotectonic analysis is a reliable tool to evaluate fault capability and to determine the fault types, and therefore to estimate seismotectonic hazard.

The study is aimed to investigate earthquake hazard zoning in Boroujerd with emphasis on urban development based on Deh Cheshmeh earthquake. The study area is located in the Zagros and Sanandaj zones in Sirjan tectonically and has a relatively high seismic activity. To study seismicity and seismic hazard analysis within a range of 200 km, the deterministic and probabilistic methods and Zare’s updated reduction relationship and Norouzi relationship have been used. In this study, raw catalogs from reputable databases such as ISC and USGS were used, and Gardner and Knopoff (1974) methods were used to eliminate dependent earthquakes. Seismic parameters were completed through using the method provided by Kiko and were the basis for analysis. The results showed that the maximum horizontal accelerations obtained in the deterministic approach were 0.23, 0.18, and 0.17 g, respectively, which were related to the High Zagros Fault (H.Z.F), Nahavand fault, and Doroud fault, respectively. Also, the maximum vertical accelerations obtained in the deterministic approach were 0.11, 0.09, and 0.08 g, respectively, which were related to the High Zagros (H.Z.F), Nahavand fault, and Doroud fault, respectively. Also, in the probabilistic approach and at the DBE design level, the maximum horizontal and vertical accelerations were 0.30 and 0.14 g, respectively, and at the OBE design level, the above components were 0.22 and 0.10 g, respectively. By using the results of this research that is gained through the possible method of maximum horizontal acceleration 0.3 and in deterministic method 0.23g, 0.13 and 0.34 decrease can be seen in base shear.

The first detailed systematic analysis of the mammal fossils from Dimeh, a new locality in the Zagros basin of Iran, is presented here. The fossil material studied includes cranial remains mostly horn cores of gazelles. Along with these fossils, some new gazelle material recovered from the renowned fossil localities of the middle Maragheh biostratigraphic levels in northwest Iran are also described. The fossils are attributed to three species: Gazella capricornis, G. cf. pilgrimi and Gazella aff. mytilinii. The last two species are recorded for the first time in Iran. The co-occurrence of the first two taxa in the Dimeh assemblage, together with other bovids, suggests a paleobiological spectrum more similar to the Samos fauna in Greece. The two gazelle species also indicate the presence of open environments in the Zagros area around 8–7 Ma (early-middle Turolian).