Use of magnetic measures to assess soil redistribution following deforestation in hilly region

Limited information is available about the use of magnetic susceptibility property to determine soil redistribution in hilly areas of the semi-arid regions. This study was conducted to evaluate the use of magnetic properties to determine soil redistribution along a hill slope following deforestation. The study area is located in the Quaternary hilly region of Lordegan district in west Iran. Ten transects were established in two land uses that included natural Querqus forested and cultivated lands. Soil samples were collected at different positions along the slope and magnetic properties (χlf, χhf, SIRM, ARM, and χfd) and selected physico-chemical properties were determined. The results (based on the χfd, SIRM/ARM) showed that the magnetic susceptibly in the calcareous materials is pre-dominantly derived during the pedogenic processes and the superparamagnetic particles which were transported to lower positions of hill slope following deforestation. The results confirmed that this methodology could be applied for monitoring soil redistribution along the slope in calcareous hilly areas in the semi-arid regions.     

The Bam Earthquake of 26 December 2003

The devastating earthquake of 26 December 2003 claimed more than 26,000 lives in the city of Bam and surrounding towns and villages in Southeast Iran, and left the majority of the Bam population homeless. The reason for this tragedy was an unfortunate combination of geological, social and human circumstances. The causative fault practically traversed the city of Bam and the earthquake occurred at a shallow depth. The residential buildings were completely inappropriate for a seismic region, being extremely vulnerable to earthquake shaking, and the earthquake occurred early in the morning when most people were still sleeping. The damage pattern was nearly symmetric about a line 3 km to the west of the surface expression of the Bam fault, and the damage attenuated rapidly with distance from this line. The industrial facilities and the lifelines performed relatively well and experienced slight to moderate damage, but this might have been due to their distance from the earthquake epicentre. However, many of the qanat (traditional subterranean irrigation channels) chains that served the twin cities of Bam and Baravat collapsed. Emergency facilities (hospitals, police and fire stations), schools and the university were destroyed and/or heavily damaged during the earthquake. The geotechnical effects of the earthquake were not significant. There was little evidence that site response effects played a major role in the damage pattern in the city. There were no reports of liquefaction and only minor sliding activity took place during the event. A unique set of strong motion acceleration recordings were obtained at the Bam accelerograph station. The highest peak ground acceleration (nearly 1g) was recorded for the vertical component of the motion. However, the longitudinal component (fault-parallel motion in N–S direction) clearly had the largest energy flux, as well as the largest maximum velocity and displacement.     

The mineralogy and petrology of the Pahnavar Fe skarn, In the Eastern Azarbaijan, NW Iran

The Pahnavar calcic Fe-bearing skarn zone is located in the Eastern Azarbaijan (NW Iran). This skarn zone occurs along the contact between Upper Cretaceous impure carbonates and an Oligocene granodioritic batholith. The skarnification process can be categorized into two discrete stages: prograde and retrograde. The prograde stage began immediately after the initial emplacement of the granodioritic magma into the enclosing impure carbonate rocks. The effect of heat flow from the batholith caused the enclosing rocks to become isochemically marmorized in the pure limestone layers and bimetasomatized (skarnoids) in the impure clay-rich carbonates. Segregation and evolution of an aqueous phase from the magma that infiltrated to the marbles and skarnoids through fractures and micro-fractures took place during the emplacement of magma. The influx of Fe, Si and Mg from the granodiorite to the skarnoids and marbles led to the crystallization of anhydrous calc-silicates (garnet and pyroxene). The retrograde stage can be divided, in turn, into two distinct sub-stages. During earliest sub-stage, the previously formed skarn assemblages were affected by intense hydro-fracturing; in addition, Cu, Pb, Zn, along with H₂S and CO₂ were added. Consequently, hydrous calc-silicates (epidote and tremolite-actinolite), sulfides (pyrite, chalcopyrite, galena and sphalerite), oxides (magnetite and hematite) and carbonates (calcite) deposited the anhydrous calc-silicates. The late-retrograde sub-stage was due the incursion of colder oxidizing fluids into the skarn system, causing the alteration of the previously formed calc-silicate assemblages and the development of fine-grained aggregates of chlorite, illite, kaolinite, hematite and calcite. The lack of wollastonite in the mineral assemblage, along with the garnet-clinopyroxene paragenesis, suggests that the prograde stage formed under temperature and fO₂ conditions of 430?C550°C and 10^?26?C10^?23, respectively.     

Earthquake prediction activities and Damavand earthquake precursor test site in Iran

Iran has long been known as one of the most seismically active areas of the world, and it frequently suffers destructive and catastrophic earthquakes that cause heavy loss of human life and widespread damage. The Alborz region in the northern part of Iran is an active EW trending mountain belt of 100 km wide and 600 km long. The Alborz range is bounded by the Talesh Mountains to the west and the Kopet Dagh Mountains to the east and consists of several sedimentary and volcanic layers of Cambrian to Eocene ages that were deformed during the late Cenozoic collision. Several active faults affect the central Alborz. The main active faults are the North Tehran and Mosha faults. The Mosha fault is one of the major active faults in the central Alborz as shown by its strong historical seismicity and its clear morphological signature. Situated in the vicinity of Tehran city, this 150-km-long N100° E trending fault represents an important potential seismic source. For earthquake monitoring and possible future prediction/precursory purposes, a test site has been established in the Alborz mountain region. The proximity to the capital of Iran with its high population density, low frequency but high magnitude earthquake occurrence, and active faults with their historical earthquake events have been considered as the main criteria for this selection. In addition, within the test site, there are hot springs and deep water wells that can be used for physico-chemical and radon gas analysis for earthquake precursory studies. The present activities include magnetic measurements; application of methodology for identification of seismogenic nodes for earthquakes of M ≥ 6.0 in the Alborz region developed by International Institute of Earthquake Prediction Theory and Mathematical Geophysics, IIEPT RAS, Russian Academy of Science, Moscow (IIEPT&MG RAS); a feasibility study using a dense seismic network for identification of future locations of seismic monitoring stations and application of short-term prediction of medium- and large-size earthquakes is based on Markov and extended self-similarity analysis of seismic data. The establishment of the test site is ongoing, and the methodology has been selected based on the IASPEI evaluation report on the most important precursors with installation of (i) a local dense seismic network consisting of 25 short-period seismometers, (ii) a GPS network consisting of eight instruments with 70 stations, (iii) magnetic network with four instruments, and (iv) radon gas and a physico-chemical study on the springs and deep water wells.     

Features of interaction between lake water and springs,and evaluation of hydrochemical composition of water in Ifni Lake (High Atlas Mountains,Morocco, north of Africa)

The National Park of Toubkal is located in the High Moroccan Atlas Mountains, one of the regions sheltering the highest summits of North Africa (Mount Toubkal with an elevation of 4167 m). The park is characterized by very important water resources, including Ifni Lake, which is the highest natural lake in Morocco (with an elevation of 2320 m). This lake is located on the southern side of Mt. Toubkal. This area has never been the object of an environmental or hydrological study. The objective of the current study was the characterization of Ifni Lake and the spring waters located in this area, as the basis of a framework to protect natural resources in northern Africa. The hydrochemical composition of water determines its origin and relationship with its catchment. Hydrochemical studies were carried out to assess the ions water composition, and processes governing the hydrochemistry of Ifni Lake water and the springs in the study area. A total of 20 water samples were collected in 2013 and analyzed for various parameters such as pH, electrical conductivity, and major ions. The physico-chemical analysis of the Ifni Lake water showed that this is the least mineralized water studied in this region, having a bicarbonate, calcium, and magnesium as dominate ions. Also there is a relationship between the hydrochemical composition of Ifni Lake and spring waters.     

The diffuse transition between the Zagros continental collision and the Makran oceanic subduction (Iran): microearthquake seismicity and crustal structure

The nature of the transition between the Zagros intra-continental collision and the Makran oceanic subduction is a matter of debate: either a major fault cutting the whole lithosphere or a more progressive transition associated with a shallow gently dipping fault restricted to the crust. Microearthquake seismicity located around the transition between the transition zone is restricted to the west of the Jaz-Murian depression and the Jiroft fault. No shallow micro-earthquakes seem to be related to the NNW–SSE trending Zendan–Minab–Palami active fault system. Most of the shallow seismicity is related either to the Zagros mountain belt, located in the west, or to the NS trending Sabzevaran–Jiroft fault system, located in the north. The depth of microearthquakes increases northeastwards to an unusually deep value (for the Zagros) of 40 km. Two dominant types of focal mechanisms are observed in this region: low-angle thrust faulting, mostly restricted to the lower crust, and strike-slip at shallow depths, both consistent with NS shortening. The 3-D inversion of P traveltimes suggests a high-velocity body dipping northeastwards to a depth of 25 km. This high-velocity body, probably related to the lower crust, is associated with the deepest earthquakes showing reverse faulting. We propose that the transition between the Zagros collision and the Makran subduction is not a sharp lithospheric-scale transform fault associated with the Zendan–Minab–Palami fault system. Instead it is a progressive transition located in the lower crust. The oblique collision results in partial partitioning between strike-slip and shortening components within the shallow brittle crust because of the weakness of the pre-existing Zendan–Minab–Palami faults.     

Comparison of LLNF,ANN, and COA-ANN Techniques in Modeling the Uniaxial Compressive Strength and Static Young’s Modulus of Limestone of the Dalan Formation

Natural Resources Research - The uniaxial compressive strength and static Young’s modulus are among the key design parameters typically used in geotechnical engineering projects. In this...     

Removal of ibuprofen from aqueous solution by functionalized strong nano-clay composite adsorbent: kinetic and equilibrium isotherm studies

The functionalized nano-clay composite adsorbent was prepared, and its properties were characterized using FT-IR, XRD and SEM techniques. The synthesized nano-clay composite was studied with regard to its capacity to remove ibuprofen under different adsorption conditions such as varying pH levels (5–9), initial ibuprofen concentrations (3, 5 and 10 mg L^?1), contact time, and the amount of adsorbent (0.125, 0.25, 0.5 and 1 g). In order to evaluate the nanocomposite adsorption capacity, the adsorption results were assessed using nine isotherm models. The results showed that the optimum adsorption pH was 6 and that an increase or decrease in the pH reduced the adsorption capacity. The adsorption process was fast and reached equilibrium after 120 min. The maximum efficacy of ibuprofen removal was approximately 95.2%, with 1 g of adsorbent, 10 mg L^?1 initial concentration of ibuprofen, 120 min contact time and pH = 6. The optimal adsorption isotherm models were the Freundlich, Fritz–Schlunder, Redlich–Peterson, Radke–Prausnitz, Sip, Toth and Khan models. In addition, four adsorption kinetic models were employed for adsorption system evaluation under a variety of experimental conditions. The kinetic data illustrated that the process is very fast, and the reaction followed the Elovich kinetic model. Therefore, this nano-clay composite can be used as an effective adsorbent for the removal of ibuprofen from aqueous solutions, such as water and wastewater.     

Geology,geochemistry, sulfur isotope composition,and fluid inclusion data of Farsesh barite deposit,Lorestan Province,Iran

Farsesh barite in the central part of Iranian Sanandaj-Sirjan zone is a sample of epigenetic hydrothermal mineralization in dolomitized limestone, which provides appropriate chemicophysical conditions making the passage of mineral-bearing fluids possible. Barite veins may range from a few centimeters to 2 m in thickness that increases downward. The microthermometry measurements obtained from more than 30 fluid inclusions show relative homogenization temperatures ranging from 125 to 200 °C with an average of 110 °C for Farsesh barite deposits. The mean salinity measured proves 16 times as much as weight percentage of NaCl for barite. Coexistence of liquid- and vapor-rich fluid inclusions in barite minerals may provide an evidence of boiling in ore veins. Moreover, occurrence of bladed calcite, high-grade ore zones, and presence of hydrothermal breccia are all consistent with boiling. Thermometric studies indicate that homogenization temperatures (Th) for primary and pseudosecondary fluid inclusions in barite range from 125 to 200 °C with an average of 1,100 °C. The δ³⁴S values of barite also lie between 8.88 and 16.6 %. The relatively narrow spread in δ³⁴S values may suggest uniform environmental conditions throughout the mineralization field. Thus, δ³⁴S values are lower than those of contemporaneous seawater, which indicates a contribution of magmatic sulfur to the ore-forming solution. Barite is marked by total amounts of rare Earth elements (REEs) (6.25–17.39 ppm). Moreover, chondrite-normalized REE patterns of barite indicate a fractionation of light REEs (i.e., LREEs) from La to Sm, similar to those for barite from different origins. The La_CN/Lu_CN ratios and chondrite-normalized REE patterns reveal that barite in Farsesh deposit is enriched in LREEs compared with heavy rare Earth elements (HREEs). Similarity between Ce/La ratios in barite samples and those found in deep-sea barite supports its marine origin. Lanthanum and Gd exhibit positive anomalies, which are common features of chemical marine sediments. Cerium shows a negative anomaly in most samples inherited from the negative Ce anomaly of hydrothermal fluid that is mixed with seawater at barite precipitation. The available data including tectonic setting, host rock characteristics, REE geochemistry, and sulfur isotopic compositions may support a hydrothermal submarine origin for Farsesh barite deposit.