JOURNAL OF GEOTECHNICAL GEOLOGY (APPLIED GEOLOGY)
Year:2008 | Volume:4 | Issue:2|Papers Count:10

The studied area is as a small portion of Sanandaj - Sirjan Zone (SSZ). Metamorphic rocks in this area subdivided to 2 groups on their setting: Regional and Contact. Slate and Phyllite are petrographic facieses of regional metamorphism. This metamorphism has affected a vast area and is of low grad in green schist (Chlorite Zone). The Boroujerd granitoid massif is elongated and parallels the prevailing schistose in these rocks by the trend of NW-SE. By the injection of it, a contact metamorphism has occurred which can be considered as a pyroxene hornfels facies. Contact metamorphic rocks, consisting of spotted schists, hornfels-schist, hornfelses and migmatites, are evident only to the north of the pluton, because the southern margin of it is controlled by a fault system parallel to the contact and the granitoid rocks are thrusted onto the metamorphic rocks. Field and microscopy evidence show that migmatites are injective and occurred by intrusion of granitoid magma into metamorphic rocks.Calculation of garnet-biotite thermometer by all of the average calibrations, account 472° C for equilibrium this two minerals in hornfels.

Soil is one of the most important resources in nay country and its degradation causes great losses for human beings, specially in arid and semi- arid regions. One of the existing views in watershed is a kind of management based on the analysis of a set of factors influencing watershed basin as a unit of soil and water resources. Geographical Investigation System (GIS) is used as an efficient means in evaluating and solving of many Problems of natural resources. In this connection, the rate of erosion and sediment yield of Kordshikh river, located in 20 Km west of Qir in Fars province, was studied using experimental models of MPSIAC, EPM and Fournier. In MPSIAC model the effect of nine important factors on soil erosion and sediment yield (surface geology, soil, climate, run off, topography, land cover, land use, present erosion condition and channel erosion) was evaluated and numerical values were assigned to them in terms of intensity and weakness of each factor. Using the sum of those values through equation Qs=38.77e0.0353R, where Qs is specific sediment (m3/ km2. yr) and R is sediment yield score, the rate of sediment yield of the basin was measured. The measured Qs for Kordshikh river was Qs=533.67. In EPM method four coefficients (basin erosion, land use, soil sensitivity to erosion and basin mean dip) were investigated in constructed network in the map. Specific sediment rate in the basin using this method was Gsp=248.94 (m3/km2.yr). In Fournier model, Qs, the rate of specific sediment, was obtained using his first method (log Qs=2.65 log pw2/pa 0.46 log H (tan S) - 1.56) was Qs=207.91 (m3/km2.yr).

Flower structures are amongst interesting phenomena in structural geology, whose three-dimensional understanding and interpretation are a bit difficult. In order to resolve this problem, a three-dimensional model has been represented, in which the type and direction of fault block movements both in plan view and cross section can be observed.Two horizontal and vertical quadratic prisms of the same size are cut to resemble the flower structure.The contact faces of the cut blocks are covered by glossy paper so as to reduce friction and facilitate their motion. The two quadratic prisms are then placed in a glass box and are pushed by wooden levers. The design of the model is such that only shearing forces act with no tensile or compressive components.The result from such set-up is that even in regions with only shearing tectonic regimes transtensional and transpressional structures form.

Analysis of grain size parameters in rivers of Torogh Dam watershed, with gravelly bed, show three sedimentary links in Moghan-Kortian sub basin that isolated from each other by discontinuities.Sudden changes in slope gradient because of tectonic effects and tributaries are the most important factors causing changes in channel bed sediment texture and generation of different sedimentary links. Also studies indicate role of two important factors, Hydraulic sorting or selective transport and abrasion, in fining trend in this watershed basin. Sediment yield in a sub basin has been calculated using EPM method that, the amount of specific erosion of basin equal to 7 tons per hectare per year and coefficient of sediment producing is 68% and amount of specific sediment of basin is 4.8 tons per hectare per year.

In this investigation, soils, sediments and rocks of urban areas of Kerman studied to assess the degree of pollution by minor and trace elements as a consequence of anthropogenic sources.37 samples were collected and analyzed by ICP-MS for 30 elements. These concentrations were compared with environmental investigation limits. From this study it was possible to observe that the fresh rocks (limestone) near Kerman city contain relatively low concentrations of majority of major, minor and trace elements as shown by background values. Soils of Kerman are anomalously rich in some minor and trace elements. Most of the soil samples displayed concentrations of these elements higher than natural background values that which suggests an anthropogenic input besides the rock and sediment influences.The accumulation of these contaminants is likely to accelerate as a consequence of rapid traffic.economic and industrial growth in the urban environment of Kerman. Geochemical maps of some major? minor and trace elements in the rock, sediment and soils were produced using geographical information system (GIS) technology. Geochemical maps showed a increasing in concentrations of some potentially toxic elements from rural areas to Kerman city center. The most polluted points are caused soils close to battery repairing stores or discarded batteries and machinery oil painting (Pb>5000 ppm). It seems that traffic and wind- blown dust are responsible for high soil concentration in some of elements like Pb Cr, Sb and Sn. However some of elements Be, Ce, Ga, Hf, In, La, Li, Nb, Re, Ta, Te, Th, U, Y, Zr did not show any pollution in this area.

In order to study of stratigraphy of Lower part of Amiran formation In Northwest and Southeast of Khorramabad, tow stratigraphic sections were chooses consist of Cham sangar section at Southeast and Tang -e shabikhon section at Northwest of Khorram Abad. In microbiostratigraphy investigations were identified 23 genuses and 35 various species of benthic foraminifera in these sections which are identified include: Loftusia minor, L. harisoni, L. coxi, L. elongata, L. morgani, L. sp., Dicyclina shlumbergeri, D. sp., Minouxia lobata, M. sp., Cuneolina sp., Antalyna korayi, Psuedolithounella sp., Broekinella sp., Omphalocyclus macroporus, Orbitoides media, O. cancavatus, O. tissoti, O. apiculata, Siderolites calcitrapoides, S. sp., Rotalia trochidiformis, R. sp., Nezzazatinella sp., Vania anatolica, Valvulammina sp., Murciella sp., Trochospirsa sp., Idalina antiqe, Dictyoconella complanata, Cyclammina sp., Dictyoconus sp., Gavelinella sp., Goupillaudina sp., Miliolids.According to the micropaleontology data, the age of Lower part of Amiran Formation at Northwest and Southeast of Khorramabad is middle to upper Maestrichtian. Micropaleontological data indicate that large quantity and size of agglutinate foraminifers in Lorestan area that seem Amiran formation s flysh were effected to the agglutinate shell growing.

The Precambrian rocks of Mahneshan Complex in Northwestern Iran were affected by regional and contact metamorphism. At the Mahneshan Complex different types of igneous and metamorphic rocks are exposed. Metamorphic rocks including metapelites, amphibolites, metavolcanite, para-gneiss, metaperidotites and serpentinites. Metapelites are foliated at two directions. Exact petrographic and petrofabric studies on them show that three metamorphic phases including two regional and one contact are affected the rocks. Andalusite, staurolite, kyanite and garnet minerals are crystallized during second regional metamorphic phase. Geochemistry studies of metapelites shows that, Composition of old meta-sedimentary rocks (source of metapelites), are shale and greywacke. Discrimination diagrams indicate an arc related tectonic setting for the source of Mahneshan metapelites. Sources of Mahneshan metapelites are intermediate felsic igneous rocks (rhyolite or andesite) base on Geochemistry of immobile elements.

In this paper the Kazhdomi and Pabdeh Formations in Marun oilfield were studied. The S2 vs. TOC diagram is one of the best methods used for interpretation of data's obtained by pyrolysis. With the use of this method geochemical properties of these two formations were evaluated, interpreted and then compared with each other. Type of kerogen for Kazhdomi Formation was determined as type II while for Pabdeh Formation the kerogen type is mixed II-III. This diagram shows that Kazhdomi Formation in compare to Pabdeh Formation has more hydrocarbon potential. The amount of dead carbon determined for the Kazhdumi Formation is about 0.93 Wt.% while for Pabdeh Formation it was estimated as 0.5 Wt.%. Absorption of hydrocarbon to rock matrix were also determined using this diagram. It show's that the amount of absorption in Kazhdumi Formation is more than that of Pabdeh Formation.This is mostly due to the presence of argillaceous matrix of the Kazhdumi Formation. This study shows that Kazhdumi Formation in compare to Pabdeh has a better quality for being a candidate as a source rock in Marun oilfield.