فهرست مطالب رضا شریفیان عطار

Water quality assessment and identification of contaminants and contaminated area where groundwater is used for drinking is very important. The present study aimed at evaluation of the groundwater quality of Joghatay plain using GQI as an indicator of groundwater quality. GQI is a suitable tool to synthesize different available quality data into easily understood format. For this reason the concentration of anions and cations in water including Na, K, Mg, Ca, SO4 -2, Cl- and TDS were analyzed. Based on the measured parameters the groundwater quality distribution map of Joghatay was provided and the groundwater quality index (GQI) was determined by GIS. GQI index value in the study area changes between 81.3 to 88.1 and it is in the acceptable range. GQI index assessment reveals that according to the distance and passing through the different formations the water quality in the northern parts of Joghaty plain is lower.

In the North & E. North of Iran Kopeh Dagh basin has formed and begins from khazar sea, passes through Turkmenistan and Iran, then inter Afghanistan. Abtalkh formation is one of the sedimentary units of this basin that has been studied based on other fossils several times such as foraminifera, palinomorphs and nanoplanctons. The study area is located in 135 Kilometers of Mashhad-Kalat road, with geographical features North latitude 59° 46' 54" and Earst longitude 36° 55' 42", and its lithology is mostly of blue-gray chalky shale with layers of marn. Its down boundary with Abderaz formation and upper boundary with Neyzar formation is conformable and its thickness is 980 M. For studying of formation according to Ostracoda, 46 samples have been taken. For separating Ostracoda of surrounded sediment, samples were washed and then were photographed by electronically microscope. We organized 57 spices for 26 genus from Ostracoda. According to, age of Abtalkh formation is santonian-masterishtian.

The Jajarm Bauxite deposit 16 kilometers E-W trending and overlis, the Karstic dolomite rocks of the Elika Formation. The study of texture and different phases has been carry out in order to understand the degree of crashing, particles size, condition of formation, degree of crystallization, porosity, distribution of constituent elements and beneficiation for the propose of digestion and potential of physical beneficiation. The phase analysis indicates that the Jajarm Bauxite is typical diasporic bauxite accompanied with Kaolinite, hematite and anatase. Hard bauxite is the high quality bauxite with Al2O3>50% and SiO2 < 9%. Mineral chemistry shows that out of 58% of Al2O3, 54.39% constituting diaspore structure, 1.6% is in kaolinite and 0.94% in topaz. where as out of 5.78% SiO2, 3.72% occurring in kaolinite structure, 1.5% as free and inactive quartz and the rest of it is located in topaz structure. The Jajarm bauxite shows a politomorphic, micro granular texture with several secondary textural elements. The size of main minerals component are generally below 10 micron, with homogeneous matrix. Kaolinite minerals forms stacks of very thin (<0.1 micron) crystal platelets. In addition, in a very hard bauxite, separation between the crystal grains and the matrix can not be done because of similar hardness for both with closely packed space filling and in consequence of the missing defined borderlines of the grains. Based on the above studies, the Jajarm bauxite can be enriched neither by grain analysis nor by the magnetic separation. Laboratory study shows, only it can be improve by water treatment.

The Jajarm bauxite deposit is so far the biggest known bauxite deposit in Iran. This deposit is located in structural zone of Alburz. In this area two bauxite horizons, called A and B, with two stratigraphic gaps can be found. The A horizon is underlained by carbonate rocks of Mobarak Formation and covered by Nesen Formation. The B horizon that constitutes the Jajarm bauxite deposit overlies the dolomite of Elika Formation of the Upper Triassic age and covered by the Shemshak Formation. Sharp contact between bauxite deposit and overlaying as well as underlying units indicate an independent source for bauxite deposit. One of the most important characteristics of Jajarm bauxite deposit is its asymmetrical morphology along the tectonic structure of the area. The geologic setting is striking16 kilometers in E-W direction. In addition to major tectonic elements parallel to the strike, there are a number of minor north-south faults in the area that have tectonically divided the mine area into four regions. Based on these studies the tectonic activities have important role in mineralogy and improving the quality of bauxite deposit. Most of the karsts and sinkholes are along the fault planes and show a positive relationship with thickness and bauxite quality. Hard bauxite and diaspore formation instead of bohemite and gibbsite as well as the repetition of different bauxite layers are the result of these tectonic activities. Therefore, the hard diasporic bauxite has played very important role in the process of alumina production. Constant profiles of: Kaolinite clay-Hard bauxite- Clayey soft bauxite and Kaolinitic clay, from top to bottom can be seen in different karst and drill holes, respectively. But the nature of upper top kaolinite is different from the bottom one. Mineralogy and variation in chemical composition (Al2O3=30% to 60% and SiO2 between 5% to 39%) are other special characteristics of Jajarm bauxite deposit.Based on the exploration activities 22 million tones of diasporic bauxite, up to 250 meters of depth along the layer of ore deposit and Al2O3 content range between 47% to 48% with about 10% of SiO2, have been proved.