JOURNAL OF GEOTECHNICAL GEOLOGY (APPLIED GEOLOGY)
Year:2011 | Volume:7 | Issue:1|Papers Count:9

The Rahmat Mountain is located northeast of Shiraz (the Folded Zagros Zone). Petrographic studies, field observations, identification of larger foraminifera, and facies studies indicate that the Dariyan Formation (Upper Aptian- Lower Albian) is composed of 10 carbonate microfacies belonging to three environments: open marine, barrier and lagoon.The depositional environment of the Dariyan Formation is interpreted as a shallow carbonate ramp.

In order to control and against the wind erosion in each area, including the Sistan Plain with 8117 km2 and with an unfavorable and dry climate, understanding the origin of the sand or the removal area of the wind deposits are extremely important. This research includes information collecting from the local erosion, general geomorphology of the region and winds, sampling of sediments for granulometry, morphoscopy and mineralogy testing and preparing thin sections of sediments. So, the major objectives of this research have been determined the critical wind erosion centers (source finding), vulnerability of Chahnimeh water reservoirs and recognition the effects of wind damage in the Zabol region. Based on the results the occurrence of droughts in the Sistan region and consequently the loss of vegetation, the Hamoon lake plain drying and the existence of the 120-day winds have been provided a suitable condition for the occurrence of wind erosion and dust storms. The Origin of the current deposits in the water reservoirs of the Chahnimeh in Zabol city was diagnosed the erosional and grueling winds with the angle of 330 to 360 degrees (north to northwest direction). The main removal facies are abandoned lands, sand prairie lands, saline and bloated land, bed Plain of Hamoon Lake and the northern plains (in Afghanistan). The sand storms and the move of sand dunes are considered as threatening factors.

Khuni area is located in Central Iran. The oldest rocks in this area are schists and phylites of Proterozoic age covering 20% of the area. Based on ore microscopic studies and geological and geochemical investigations, ore mineralization of the studied area is classified into two major groups. First, the Kazemi group consists of mineralization which is composed of base metal sulfide mineralization and is formed under low temperature conditions. The second group is represented by the northern mineralization and Cheshmeh Khuni occurrences, which are composed of oxide mineralization with low concentration of base metals. The second group mineralization has important values of Au.Lithochemical analysis of collected samples from veins and alteration zones in Khuni area indicates that the gold mineralization have a volcanic host. Based on lithochemical analytical results of samples from Cheshmeh Khuni mineralization, the minimum, maximum and average gold grades are 2 ppb, 4810 ppb and 475.70 ppb respectively.

An area of 388 thousand hectares of land covered with three geotechnical and sedimentological distinctive different types of losses in Golestan province have been studied. Criteria such as distance and transport mechanisms, texture, dry density, plasticity properties, void ratio, compression, chemical and mineralogical composition and structure of losses, are standard criteria of engineering geology, which control the geotechnical characteristics of the losses. Based on these criteria the losses of the three areas were assessed. It was concluded that the origin of the geological and geotechnical sedimentation of the soil controls largely the behavior of the losses.

Padena area of Semirom is located in southern Isfahan province with an area of about 70 km2. Every year many landslides occur in this area and cause damages to the only road connecting Sarbaz and Dashtbal villages. In this article, geographical information system and ILWIS programs were used to evaluate the effective factors causing landslides, and appropriate stabilization methods were recommended. After preparing a landslide distribution map, the effective factors in occurring landslides such as lithology, distance from drainage systems, slope, annual precipitation, distance from road, vegetation and distance from fault were evaluated, and finally a landslide hazard zonation map was prepared.The results indicate that about 40% of the landslides were located in the very high potential landslide zone, 26% in the high potential, 20% in the medium potential and 14% in the low potential zones. At last, preventive methods, such as using gabion and huge rock size in slopes adjacent to rivers, reduction of sharp slopes with attention to lithology of marble, using detour channels with attention to the meandrous shapes of rivers, using surface drainage systems with dendritic shape for rapid drainage of surface water, and vegetation management were recommended.

The most solid materials of a building, from Persepolis to the Pyramids of Egypt, are stones, which are lasting for thousands of years. Crushed building materials called gravel and sand are the most used materials. The progress of men’s civilization in building structures has increased the need for gravel. The uncontrolled exploitation due to this need necessitates the protection of river beds and their limits, preventing the losses of equilibrium and the uncontrolled exploitation.In this paper we tried to study the destructive and indirect effects of the exploitation of rivers on the environment via our field trip to the main axis providing the gravel of Mashhad (Sarakhs, Kalaat, Fariman, and Ferdowsi). Furthermore, the trip was aimed at finding replacing alternatives and suggesting new building materials. The bedrocks of Sarakhs axis-due to the numerous sand washing machines- taken for case study show compressive strength of approximate 420 to 450 kg/cm2. The volume of this limestone mine was determined by GIS software and estimated at about 1044.37 million tons. The great strength and large volume of this mine confirm the alternative usage.

In the Copper Mine Sarchashmeh the copper ore mining operation in geometric terms, the status of ground water, rock mechanical properties, physical characteristics, geometry of fractures and penetration of dykes caused the walls of the mine to show different behavior in terms of stability. All these characteristics provide the worst stability conditions for the western wall of the mine. In addition, the granodiorite dykes in the western part of the Copper Mine created thorough changes in size, form of mining mass, mineralization, hydrology and geomechanical behavior in the rock mass.Most of the intrusive mass are extended along the western wall and exacerbate the potential instability. Special status in relation to fractures in the rock surface of mining operation in the western wall creates conditions that in case of earthquake events with 24 g horizontal acceleration, the more than 50 degrees steep walls became instable and great masses of the stones will slip in form of plates along tensional joints. It is not unexpected that in such conditions small wedge masses slip along the interface of B2 and B3. Moreover, there is potential for circular slips on the crushed rocks and debris from the mining sector. Mechanical characteristics of the debris are so that by seismic loading, walls with slopes greater than 20 degrees became instable. Basis design of (DBL) will be instable in case of earthquake events with 24 g horizontal acceleration. The landslide will bring a lot of damage and the exploitation of mineral in deeper rocks will be more difficult.

In this study, by using data resulting from analyses of the Shemshak Formation's shales located in Siahbisheh area, some relationships for the estimation of UCS by other rock properties such as point load index (Is (50)), durability index (Id), liquid limit (LL) and porosity (n) are presented. For establishing these relationships, mathematical modeling has been used. Statistical investigations show that if UCS is estimated by an independent variant, the point load index (Is (50)) and the fourth cycle durability index (Id4) are more useful and efficient than the other surveyed parameters.Applying two independent variants could result in improving the estimating model. The best relationship is elicited from the point load index (Is (50)) and fourth cycle durability index (Id4) as independent parameters for all samples. In the next step, the samples were classified into three groups such as very low strength samples, low strength samples and medium strength samples. The relationships in each group were studied. According to their UCS, three distinctive relationships between independent variants can be estimated which are the best estimation. For very low strength samples, the relationship between liquid limit (LL) and the fourth cycle durability index (Id4) is the most efficient state, whereas for low and medium strength samples, the point load index (Is (50)) and the fourth cycle durability index (Id4) show the best results for determining UCS. According to the results, with increasing of UCS, the prediction performance of the point load index increases, whereas the performance of the durability index (Id), liquid limit (LL) and porosity (n) decreases.