فهرست مطالب

Earth Sciences - Volume:4 Issue: 1, Apr 2012

Iranian Journal of Earth Sciences
Volume:4 Issue: 1, Apr 2012

  • تاریخ انتشار: 1391/06/20
  • تعداد عناوین: 8
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  • Koml, Oacute, Ssy George Page 1
    Sampling of any geological formation needs comprehensive knowledge of the rock genesis, through the dia- and epigenetic processes (secondary alterations) up to the physical properties and the chemical and mineralogical composition of the rock. Well established theoretical knowledge should be complemented by practical experience. Besides the geological exploration of a raw material, its representative sampling is the most responsible task of the expert. Elaboration of the technology of the mineral processing i.e. the operating cost of the plant highly depends on reliable sampling which is essential for an optimal utilisation of the deposit. Nowadays, when green-field plants below 1 Mt/a capacity are rarely set up, proper sampling is even more important than before. Several million USD/annum can be saved in operating cost with a well-established sampling procedure which, according to the experience of the author, is often neglected by the investors or project management. In this paper the author clarifies the terminology of the characteristic and representative samples and introduces several typical cases both for karst and laterite bauxites.Distinction is made between technologically homogenous and heterogeneous type deposits. Examples are taken from Iranian, Indian, Vietnamese, West African, and South American deposits. Proposals are given for sampling procedures in different stages of the exploration, when the first samples are to be taken for technological tests. The question is investigated whether the bauxite is necessary for an already operating plant (when the bauxite should be fitted to the plant) or when a green- field refinery technology is to be fitted to the deposit(s). In conclusion, it is established that no reasonable economy may exist for mining and alumina processing separately. The economy of the mine and the plant is to be regarded as a single economic unit. For achieving this purpose reliable representative samples are necessary.
    Keywords: Bauxite, Sampling, Alumina manufacturing, Refinery
  • Pajovia Marko, Radusinovia Slobodan Page 12
    Production of Metallogenic-prognostic map (MPM) was preceded by the preparation of instructions that define three phases of work: preparation (with preparation of the Project), realization of field and laboratory research and data processing with production of different maps and, finally, production of the prognostic map with the accompanying instruction book. During the Project realization, the main task was construction of high-quality structural-geologic map at the scales of 1:25,000 and 1:50,000. Particular attention was paid to facial (lithological-stratigraphic) characteristics of geological formations in the hanging wall and footwall of Jurassic bauxites, including a detailed survey of numerous geologic columns. Besides, up to four geologic columns with detailed sampling for chemical, mineralogical and geochemical analyses were measured in each deposit and occurrence of bauxite. Production of special-purpose maps of the bauxite-bearing area was based on the geologic map and geologic cross-sections at the same scale. In order to produce these maps, particular criteria were defined and worked out, including classification and scoring according to the class. The next phase involved the production of the Basic map for MPM, with basic geographical ang geological contents. Isolines and scoring data were transferred to the MPM from the special-purpose maps. After that, points were gathered into six classes. Isolines were constructed by the perspectivity classes with the following scores: I: 4-6; II: 7-11; III: 1214; IV: 15-19; V: 20-22; VI: 23 points. In this way, regional zonation of the bauxite-bearing area was made according to the level of perspectivity, i.e. the Metallogenic-prognostic map of the investigated area was produced.
    Keywords: Metallogenic, prognostic map, Red bauxite, Karst bauxite, Paleorelief, Footwall, Hanging wall
  • Limaye Shrikant Daji Page 21
    Out of about 1.2 billion people in India, 68% people live on agriculture as their main occupation. Ground water is therefore an important resource which provides over 70% of rural drinking water supply and about 50% of water used for irrigation. Rains in Monsoon season from June to September, provide the main source of water but they last only for four months and the rest of the year is dry in most of the hard rock region. About 67% of India is occupied by hard rock terrain and about 30% of the hard rock area falls within semi-arid, drought-prone zone receiving less than 500 mm rainfall per year. In semi-arid, hard rock terrain in India and in many other low-income countries, the surface water resources are scarce and polluted. Ground water occurs in this area in the shallow weathered zone up to about 15 meters depth and in the deeper fractures and fissures up to about 100 m depth. Bore wells reaching up to 60 to 100 meters depth, installed with hand-pumps, are very common for providing safe drinking water supply to villages. This causes a positive improvement in the health of villagers and an economic advantage by reducing the number of working days lost due to illness. Agricultural production in these semi-arid areas is just marginal because the rain-fed crops suffer from the vagaries of Monsoon rains. The average farm-size per family of 5 persons is about 2 Ha. There are 3 to 5 drought years within a span of 10 years, which leave the dry-land farmer in perpetual poverty. In the past 3 years, over 4,200 farmers have committed suicide due to continued crop failures. Ground water, therefore, forms a very important and reliable resource which, if available in a farmer’s plot of land and if utilized prudently for irrigation by digging or drilling a well, could transform the farmers lifestyle. Even if the farmers are able to save one rainy season (Monsoon) crop through protective irrigation from dug well, and if possible take winter and summer crops on small plots, they would stabilize in the rural scenario. Otherwise, the farmers would migrate to nearby cities and stay in slums. Many cities in India and other low-income countries are suffering from an ever-increasing flux of rural population thereby chocking and polluting the urban environment and putting stress on urban infrastructure. Ground water development for irrigation is the lifeline for rural economy. However, in many watersheds in semi-arid, hard rock areas, the pumping of ground water is increasing and in some watersheds it is more than the recharge available from rainfall. In these over-exploited watersheds, the yields from the wells are not sustainable. Still, farmers in hard-rock area of peninsular India are taking all risks to develop ground water for irrigational and domestic supply because of the economics underlying its use. This paper discusses the economics of ground water use and gives guidelines for sustainable development, such as availability of soft loans to farmers, insurance for failed wells and people’s participation in augmentation of recharge to ground water. Some of these guidelines have been included on the website www.igcp-grownet.org of UNESCO-IUGS-IGCP Project GROWNET, (Ground Water Network for Best Practices in Ground Water Management in Low-Income Countries) for which the Author of this paper is the Project Leader. Reverse migration from cities to villages is possible only if sustainable ground water development is done in these semi-arid areas, through watershed protection and recharge augmentation activities, as advocated by the GROWNET project.
    Keywords: Economics, Groundwater use, India, UNESCO Project GROWNET
  • Hamed Mosavian M.T., Khazaei I., Aliabadi M Page 25
    Adsorption capacity of Cr (VI) onto sawdust of aspen tree and activated sawdust, was investigated in a batch system by considering the effects of various parameters like contact time, initial concentration, pH, temperature, agitation speed, absorbent dose and particle size. Cr (VI) removal is pH dependent and caused to be maximum at pH 2.0. The amounts of Cr(VI) adsorbed increased with increase in dose of both adsorbents and their contact time. Experimental results show that the low cost biosorbent was effective for the removal of pollutants from aqueous solution. The Langmuir, Freundlich and Temkin isotherm were used to describe the adsorption equilibrium studies of agrowaste. Freundlich isotherm shows better fit than Langmuir and Temkin isotherm in the temperature range studied.
    Keywords: Chromium, Aqueous, Lignocellulosic solid wastes, Adsorption, Sawdust
  • A.V. Gusarov Page 31
    This paper uses the results of river suspended sediment flux (SSF) analysis to propose a new hydrological method for quantitatively estimating the river bed and drainage basin (sheet erosion, rill and gully erosion) components of total erosion intensity in river basins. The suggested method is based on the establishment of the functional power connection between mean monthly water discharges (WD, Q i) and suspended sediment fluxes (r i) calculated for the low-water-discharge phases of a river’s hydrological regime in various (on mean annual water discharges) years: r i = a×Q i (where a, ì are some empirical coefficients), and further extrapolation of this connection for other phases of the hydrological regime. Thus, the extrapolation allows us to calculate (in a long-term annual SSF) the proportions of sediments originating in river beds and drainage basins. The proposed method is tested using a long-term (not less than 10 years) series of observations for WD and SSF of 124 chiefly small and midsize rivers of the East-European plain, the Urals, the Eastern Carpathians, the Ciscaucasia and the Caucasus, and Central Asian mountains, containing data on the mean monthly values of WD and SSF. The paper also compares the method with other methods for estimating the components of erosion intensity and SSF.
    Keywords: Erosion, Drainage basin, River bed, Suspended sediment flux, Suspended sediment structure, Northern Eurasia
  • Musa Hussain Hussain, Joshi H., Singhal D.C., Kumar S., Rao Page 44
    The changes in human population often correspond with change in land use, including expansion of urban areas, agriculture and increasing industrialization, which necessitate increasing the available amount of drinking water. As the surface water sources are under the pressure of pollution, it has become necessary to use groundwater at an increasing rate. Groundwater recharge can be abundant in the alluvial plains where the urban areas are often located. Such areas can face danger of pollution of groundwater and the changes in land use are likely to result in change in groundwater quality. Keeping these aspects in view, it was planned to development a groundwater water quality index in the Ganga-Yamuna interfluve area of northern India, The objective of the present study is to develop the Index of Aquifer Water Quality (IAWQ) inside the Geographic information system (GIS) environment, which can be used by the field investigators and modeler’s in assessing the groundwater vulnerability. The formula to estimate the IAWQ index is adopted from the procedure suggested Melloul and Collin (1998). The procedure developed for this involves weights assigned to these 8 parameters as per their analytical hierarchy in violating the (drinking water) standards and not as an arbitrary means (as taken by Melloul and Collin). The suggested procedure can be extending to include more number of chemical parameters as necessitate in individual case studies. In the modified procedure presented in the present study, the number of measured chemical parameters n is taken as 8 (Cd, Mn, Pb, Fe, NO3-, Total Alkalinity, TDS and Ca2+) as against n=2 (chloride and nitrate) as taken in the Melloul and Collin’s work.
    Keywords: GIS, Water Quality Index, Hydrogeology, Groundwater
  • Taherpour Khalil Abad Morteza, Fazel Valipour Mohammad Ibrahim, Torshizian Habib Allah, Taherpour Khalil Abad Vida, Asmaryan Shushanik Page 51
    The remains of the natural and human activities in some parts of the earth register as geopark. Actually, geopark is one or more geological phenomenon which is important from ecology, history, culture and archeological view. The aim of the geotourism description in an area and creating a geopark is trying to keep the earth\''s inheritance and locality the economic of the area. Iran with an old history, diversity of the environment and a lot of geological phenomenon has a great potential in creating geoparks. From this point of view, we can divide it into the five geotourism areas which are as follows: North, South, East, West and Central part of Iran. The Kashmar township is an area which is located in the south part of the Khorasan-e-Razavi province in the Northeast of Iran. This area because of the nearness into the desert, is hot and dry. The area is rich of mines, hot-water springs and geological landscapes. In this research, we tried to introduce some examples of the geotourism features in the study area such as faults, mines, hot-water springs, Bejestan playa, Asyab-e-Khooshab valley, Kavir-e-Lut salt desert, Bijvard entrance, Sar-e-Borj waterfall, Sir and Ahoo Bam caves and Natural glacier.
    Keywords: Geotourism, Kashmar township, Geoparks, Iran
  • Mazhari S.A., Sharifiyan Attar R Page 61
    Apatite minerals of I-type Zouzan granitoids and typical garnet-bearing S-type granites have been analyzed by electron microprobe to define trace element concentrations and compare them in different granites. Zouzan granites are composed of apatites with lower Fe, Mn, Na and HREE and higher REE and ∑REE relative to S-type ones. Trace elements abundances of apatite often vary with some parameters of the host rock, especially aluminum saturation index (ASI). Strontium content of apatite is very sensitive to whole-rock composition and binary diagrams of SrO- trace elements could be used to discriminate different granites and realize magmatic evolution in a single phase. The apatite concentration of Fe, Mn, Na and HREE increases during magmatic fractionation in Zouzan pluton, while Sr and REE decreases. The difference of REE concentrations in apatites of mafic and felsic rocks of Zouzan granitoids relates to the coeval or earlier crystallization of amphibole and titanite, respectively. Acicular apatites which are present in granodiorites and mafic microgranular enclaves show exceptionally dissimilar composition in comparison with other apatites in the same sample and host rock geochemistry. Extraordinary high levels of Fe, Mn, LREE, (Sr apatite /Sr bulk-rock)>1 and unusual low HREE indicate that a more mafic magma was involved in magma genesis of Zouzan pluton and confirms magma mixing
    Keywords: Apatite, Granite, I, type, S, type, Trace elements, Zouzan pluton