JOURNAL OF GEOTECHNICAL GEOLOGY (APPLIED GEOLOGY)
Year:2010 | Volume:6 | Issue:3|Papers Count:9

The fluid inclusion studies indicate three different types of aqueous fluid inclusions at the Emarat deposit, namely highsalinity brine (type II), low salinity meteoric water (type III), and a fluid of intermediate salinity (type I). The high salinity (type II) brine exhibits an average salinity of 15 wt.% NaCl equiv. Low-salinity (type III) inclusions are characterized by an average salinity of 1.7 wt.% NaCl equiv. Inclusions of intermediate composition (type I inclusions) possess an average salinity of 7.8 wt.% NaCl equiv. This fluid of intermediate salinity is best explained as a mixture of high-salinity type II and low-salinity type III fluids.Homogenization temperatures for fluid inclusions occupy a wide temperature range between 90oC and 257oC, with 80% of all inclusions falling in the range of 150oC and 257oC. No significant differences in homogenization temperatures exist between the different types of aqueous liquid-vapor inclusions.Fluid inclusion data provide very strong evidence for fluid mixing at the Emarat deposit. This and the large range of homogenization temperatures may be used to suggest that fluid mixing and cooling were two important mechanisms contributing to mineral deposition at Emarat.

There are different methods which have been developed and applied to extract building stones. As time goes by and with the improvement of technology, the primary methods in which human force played a significant role were abandoned.Therefore, the selection of an appropriate method among all existing methods is a multi-criteria decision. Nevertheless, at first, the available criteria should be studied and their side effects considered, only then can the appropriate method be selected. In the present paper, the developed methods including diamond cutting-wire method, blasting method, cleat-beam method, cut rock expansive material and fact expansive material have been compared using TOPSIS method by considering the following factors: grass income, safety, desirability, reduction of environmental impacts, waste and reduction of extracting time. Those criteria having the same impacts in all methods were not considered. Consequently, the diamond-cutting wire method was suggested as the most appropriate method to extract the building stones.

The medicinal plant named Nepeta astrotricha, a spearmint species, is found at Barfkhaneh Tezerjanin in Shirkuh Mountains, southwest of Yazd. The growth location of this rare plant has been studied from points of view of petrology and geoecology in order to recognize the main factors related to the plant germination in this specific area. The geoecological investigations in current research as a bridge between geology and ecology indicate the application of this science for expressing the plant and soil relationship with the geological conditions. Research methods are mostly based on the field study, ecology of plant evolution, collecting soil and rock samples, chemical analysis and microscopic study of thin sections. The results indicate that the amounts of some elements such as iron, magnesium and calcium in the soil of growing location are higher than the normal average of granitic rocks because of the special composition of the rocks and minerals in Shirkuh granitoids. On the basis of petrological study, the granitoid rocks in the growth location are granodiorite, mica granite and monzogranite. Alteration of these igneous rocks along with limestone and conglomerate in the area has provided the necessary elements for growing Nepeta astrotricha on the middle slopes of the Shirkuh Mountains.

In this investigation, concentration and mobilization variability of some toxic elements in sewage of Zarand coalwashing plant were studied to assess the degree of pollution as a consequence of this plant. Water samples were collected in June, November, January and February from entrance and exit water in addition to Akbarabad sump water and analyzed by FLAA for Ag, B, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn. From this study, it was possible to observe that the concentration of most elements increased highly after leaving the coal-washing plant and in the Akbarabad sump water that indicated entrance of pollutants from this plant. Concentration of the elements in the sump of sewage was relatively lower than in the exit water that was due to adsorption of these elements by coal particles, Fe-Mn hydroxides, clay minerals and algae existing in that sump. Also, observations showed that the concentration of all of the toxic elements in hot months was higher than cold months by reason of increasing solubility of the elements, decreasing pH of sump water (because of decrease in solubility of Ca-Mg carbonates and sulphates), increasing evaporation and decreasing rainfall and runoff to the sump. Concentration of most toxic elements in the sewage of the sump was higher than recommended maximum concentrations of toxic trace elements in irrigation water. Remediation methods such as increasing pH, aeration and using colloids were proposed to decrease the levels of the elements in the Akbarabad sump water.

The results of testing unconfined compressive strength show that in case of existing sodium chloride, the sample’s strength will decrease after 7 days, but increases after 28 days. Of course this happens by low amount of sodium chloride, i.e. <3%, otherwise the strength decreases. The existence of sodium chloride salt in soil causes the increase of lime effect and intensifies the increasing of compressive strength, resultant of poozolanic reaction. By increasing lime amount, the effect of sodium chloride decreases and also by increasing the sodium chloride percentage, relative compressive strength of samples decreases. Generally up to 3 percent sodium chloride, the increasing of lime effect on soil strength is considerable.

One of the most important tasks of underground structural designing engineers is to find the best way for providing stability of structure according to geotechnical properties. Because of difficulty and cost of accurate achieving of designing parameters, empirical methods for the stability analysis of the spread area have been used. In this study we investigated the engineering quality of ophiolitic melange rock masses in the Azad tunnel route by laboratory and field studies and bore holing. After categorizing rock masses, RMR, Q and GSI, their geomechanical properties were evaluated. Adequate supporting systems for tunnel with 6 meters span were evaluated based on ground squeezing potential by use of Bieniawski and Barton suggesting methods as well as Sing and Goel criteria. At last the stability of the tunnel was assessed.

Nannostratigraphic investigation of Surgah Formation has been carried out on Well No.10 in Tang-e Bijar Gas field and the following results were obtained: A total of 56 species from 31 genera were identified, described and recorded for the first time from well sections. Their distribution point to deposition of Surgah sediments during UC8 to UC12 zones indicating Middle Turonian- Early Santonian age. Correlation points of Surgah Formation has a younger age than Type Section in its base in Well No.10. The environmental condition of Surgah sedimentary basin was shallow sea, rich in nutrients and located in low latitudes.

The Ramsheh region is located in the northeastern margin of the Zagros orogen. It is one of the regions that deformed during and after constructional and strike-slip movements of the Zagros collision. This region is located between the Ramsheh and Shahreza faults and shows brittle and ductile deformations. Major faults of the region are active, and Quaternary deposits have been displaced and cut along the faults. Paleo-stress studies indicate that the Ramsheh region has been affected by south-southwestward shortening, and dextral strike-slip movements have an important role in the tectonic evolution of the region. During the movements a positive flower structure has been formed between the major faults.