SHAHID CHAMRAN UNIVERSITY JOURNAL OF SCIENCE
Year:2006 | Volume:NEW SERIES | Issue:14|Papers Count:6

Ramhormoz plain is one of the agricultural poles in Khouzestan province. Partial use of groundwater potential, decrease of precipitation and lack of management in groundwater have caused the cultivable lands not to be fully expolitated and surface soils gradually being converted to idle lands because of erosion. For this reason, conjunctive use of groundwater and surface water resources has been proposed for overcoming these difficulties, and groundwater modeling, as an efficient and economical tool for evaluation of management alternatives, has been suggested. Different climatological, geological, hydrogeological and hydraulic data have been collected and analyzed for this purpose and after preparing the conceptual model, necessary data have been defined as input to various software packages of V.MODFLOW.V.2.6. First, time period of December 1994 to August 1996 was divided to 4 time periods of one month time steps and model was calibrated by trail and error's estimation of hydrodynamic coefficients. Then, the model results were optimized by PMWIN through PEST code. After verification of and assurance from reliability of the model, the model was used as a management tool and different management alternatives, including current pumpage, development of aquifer by drilling new wells, effects of drains and assessment of response of aquifer to import water for irrigation were examined by the model. The results of simulation show that from management point of view, the current pumpage (withdrawal) is not an accepted alternative. On the contrary, drilling wells in the East part of the study area and construction of drains in the North and South, parts of study area are suitable alternatives.

Dispersivity is a measurable property of a geologic system and one of the parameters of advection-dispersion equation. In this research, the dependence of dispersivity on soil thickness is investigated in coarse and medium homogeneous sands. Experiments were carried out in a rectangular laboratory-scale Plexiglas tank, 0.72 m long, along which the main flow was imposed, 0.1 m wide and 1.2m high. A solution containing 8 g/l (Ec=14 ds/m) sodium chloride concentration was used as the nonreactive contaminant. Experiments were carried out with soil thicknesses of 0.1 m in sequence up to 1 m with an increment of 0.1 m. Dispersivities obtained from the analysis of breakthrough curves data ranged from 0.31 to 0.64 cm for coarse sand and 0.13 to 0.46 cm for medium sand. The results indicate that dispersivity is independent of soil thickness in the coarse and medium sands investigated.

Sarsefidal area is situated in a volcanic-plutonic belt north of Darouneh fault. Magmatic activities started in this belt in early Tertiary mainly as acidic to intermediate tuffs and andesitic lavas. Based on fossils found in limestone beds within the tuffs, volcanic activity started in Lower to Middle Eocene times. Two types of intrusive rocks are exposed at the surface: 1) trondhjemite and 2) quartz monzonite. Magmatic water associated with trondhjemite (Na-rich fluid) caused very broad alteration zones from the surface to depth such as: silicified zone, argillic zone and albite zone. Sarsefidal trondhjemite is peraluminous type granite. Based on Rb/Sr ratios versus Color Index diagram trondhjemite displays high Color Index but low Rb/Sr ratio, and does not plot in the field of Sn or Mo porphyry systems. Quartz monzonite plots in the field of Cu-Au porphyry deposits. High Au, Cu, Zn and other elements are associated with monzonite to quartz monzonitic rocks. Cu-vein, Au and other elements anomalies, very broad zones of alteration (at Uchplang and Baharieh south west of Sarsefidal), favorable structural setting and sub-volcanic rocks all indicate that the area around Uchplang-Baharieh has a great potential for porphyry Cu -Au deposit.

Hassan-Abad and Darreh-Zereshk granitoid intrusions and their hosted skarns are located at 60 km southwest of Yazd, between Central Iran and Sahand-Bazman tectonomagmatic belt. These intrusions with probably Oligo-Miocene age are intruded into Eocene volcanosedimentary rocks, Cretaceous conglomerates of Sangestan Formation, and carbonate rocks of Taft Formation, and have caused skarnization and minreralization in the study area. The purpose of this study is a comparison of geochemical characteristics of the SW-Yazd granitoids with those of World skarn garnitoids and evaluation of mineralization potential of the Hassan-Abad and Darreh-Zereshk skams. To this end, 16 samples were collected from both magmatic, and skarn rocks for XRD and XRF analyses and 20 samples were systematically selected for petrographical studies. Based on geochemical and petrographical studies, these granitoid intrusions were derived from an I-type calc-alkaline magma with granite to quartz diorite composition in a syn-collisional tectonic setting, like most worldwide skarn granitoids. According to geostatistical studies (Kuscu et al. 2002) among harker diagrams, SiO2 vs. MgO, SiO2 vs. K2O, SiO2 vs. K2O + Na2O, SiO2vs. (FeO t + CaO + Na2O) /K2O as well as Ni vs. V are more useful than other diagrams in distinction between Fe-, Cu-, Au- and Mo-, W-skarns. Comparison of major and trace elements of the South West Yazd with worldwide skarn granitoids shows that Hassan-Abad and Darreh-Zereshk granitoid skams are similar to the geochemical characteristics ofplutons associated with worldwide Cu and Fe.

Kerman is a large and ecologically varied province in South-central Iran. Its area is 18600 square km, and unfortunately its bat fauna is very poorly known. In this research different bats such as Asellia tridens, Pipistrellus kuhli and Rhinoiophus biasii were found and have been reported by different researchers. One species of bat Rousettus aegyptiacus was found for the first time from Faryab in Geroft, 370 km on south of Kerman. It is a fruit bat and belongs to suborder of Megachiroptera. Some of its prominent characteristics are: large size, simple ears in which the inner margin of the pinna forms a complete ririg, large eyes, a vestigial tail and a very short uropatagium. The second finger retains three phalanges and is clawed. The skull has a long rostrum.

Zagros is a Fold thrust belt which is extended from North West to South Center of Iran. This mountain range is truncated and disturbed by Tear faults (with NWN-SES trend). Due to study of setting of these faults in evolution of Zagros basin, the Sabz Pushan fault zone is selected as a case study. Facies and thickness contour maps controls and field investigations revealed that the fault zone was frequently active from Middle Cretaceous (Cenomanian) to recent time. From WSW to ENE, the main pieces of evidence of these activities are: A) thickness increase of Sarvak Fm, B) facies change of Gurpi shale and marl to Tarbur limestone, C) facies change of Pabdeh marl to limestone-dolomitic facies of lahrum Fm, D) facies change of Gachsaran evaporates and marls to multi-colored marls of Razak Fm, E) facies boundary of Mishan Fm and F) thickness increase of Aghajari Fm. and prevention of transportation of Bakhtiari Cherty component to WSW. Despite older activities of same tear fault in Zagros, no evidence of pre-middle Cretaceous activities of Sabz Pushan is documented.