2024-03-29T00:48:30Z
https://jtethys.journals.pnu.ac.ir/?_action=export&rf=summon&issue=481
Quarterly Journal of Tethys
JTethys
2476-7190
2476-7190
2013
1
4
Association of Silica Fractal Distribution with Gold Mineralization: a case study from the Takmeh-Dash Region, NW of Iran
The Takmeh-Dash region comprises a wide variety of igneous bodies that have been developed from early to late Neogen. The granitic rocks and related aplite apophyses have been developed along fault-dominated structures which defines a well pronounced mineralized zone. According to isotopic and fluid inclusion studies, most of the quartz-pyrite units are solution-related with some traces of Cu, Pb, Zn and Au in an epithermal regime. In addition, well-developed alteration haloes are recorded around the intrusions and they include a variety of silica phases in which the textural patterns are similar to that of Queensland (Australia). This study introduces a new method for the prognosis of gold mineralization potentiality in an aplitic facies on the basis of self-organized silica textures as well as textural variations in vein type deposits. With the aid of sampling and microscopic investigation, necessary databases have been acquired from the mineralized region before a fractal analysis of silica distributions by power law relationships. It is an innovative approach toward prospecting the self-organized textures of which similarities have a legitimate relation with boiling point mineralization in epithermal environments. As a result, the Takmeh-Dash mineralogical patterns appear to include stepwise textural variations with peculiar zonal appearances due to post-magmatic procedures. For prospected sub-regions, the silica fractal dimensions not only indicate to maturity of quartzitic veins but represent an enough geological potential for the development of colloformed-crustified gold-bearing sequence in a deeper altered formation.
Epithermal gold
Fractal distribution
Silica distribution
Textural zoning
2013
12
01
241
253
https://jtethys.journals.pnu.ac.ir/article_2773_c1814bc650fe2a93f1de8d502c019c39.pdf
Quarterly Journal of Tethys
JTethys
2476-7190
2476-7190
2013
1
4
Hydrogeochemistry and groundwater quality assessment in Nour coastal plain, Mazandaran province, Iran
Groundwater quality in Nour coastal plain in Mazandaran province of Iran is assessed by measuring physicochemical parameters including total dissolved solid, electrical conductivity, pH, total hardness, major cation and anion compositions and Nitrate pollution. For this purpose, fifty groundwater samples were collected in July 2012. The hydrochemical types, Ca–HCO3 and Mg–HCO3 dominate in all samples of groundwater. Nearly 98% the groundwater samples fall in the very hard category. Mineral saturation index of groundwater were calculated by PHREEQC. The all groundwater samples are oversaturated with respect to dolomite and calcite. According to Wilcox classification diagram, 98% of groundwater samples classified as C2–S1and C3–S1. In 80% of the groundwater samples sodium hazard was classified as low. In comparison with the WHO’s drinking water guideline of 50 mg l–1 for NO3–, the NO3– concentration in groundwater was lower than this limit. The Kruskal–Wallis test is used to compare the NO3– parameter between five land uses. The result of Kruskal–Wallis test shows that samples have similar NO3– parameter in different land use.
Geochemistry
Groundwater
nitrate
Water quality
Sodium absorption ratio
Iran
2013
12
01
254
265
https://jtethys.journals.pnu.ac.ir/article_2774_47add64823aad154e73bf27971f7484a.pdf
Quarterly Journal of Tethys
JTethys
2476-7190
2476-7190
2013
1
4
Investigation of Electrokinetic for the Removal of Mercury from Contaminated Soil and Sediment
Electrokinetic remediation is one of the most promising in situ or ex situ processes for decontamination of heavy metals, anions and polar organic compositions from the soil. In this study, we investigated the efficacy of this method in removing mercury from clayey soil (with kaolin to sand weight ratio of 2:1) and from gold mine tailing dam sediment and determined optimum removal conditions. Total mercury concentration in the soil and sediment samples was 800 and210 mg / kg, respectively, and duration of the experiments was considered as 32 and 30 days, respectively. The experiments were conducted on the samples with two voltage gradients (1.0 and 1.5 VDC/cm) to assess the effect of voltage gradient when using 0.1 M Na-EDTA, 0.1 and 0.4 M KI solutions and distilled water. The results showed that the best efficiency (99.07%) was reached when the 0.4M KI concentration was used with the 1.0 VDC/cm voltage gradients, leaving a residual concentration of 7.47 mg/kg in the soil after the treatment. In addition, the best efficiency for mercury removal from the tailing dam sediment was achieved in these conditions. The electrical current profiles, pH of the anode and cathode reservoirs, electrical conductivity of the soil and its moisture were then plotted and discussed.
Electrokinetic
Mercury
KI
Na-EDTA
2013
12
01
266
281
https://jtethys.journals.pnu.ac.ir/article_2775_f7062d2b304559614fc0ff37da9401f4.pdf
Quarterly Journal of Tethys
JTethys
2476-7190
2476-7190
2013
1
4
Kinematic vorticity analysis within the Zagros hinterland involved-basement window, Tutak gneiss dome, southwestern Iran
Dehbid mylonite nappes associated with the Tutak gneiss dome as the Zagros hinterland involved-basement window in the Zagros Orogenic Belt has significant components of dextral sense of shear along the mylonite nappes and are related to the high proportion of simple shear relative to pure shear deformation. Kinematic vorticity analysis (Wk) was made in order to determination of relative amounts of simple shear and pure shear components. The kinematic vorticity analysis has taken as evidence of porphyroclasts rotation relative to internal reference frames during non-coaxial deformation within the Tutak gneiss dome in the Zagros Orogenic Belt. The quartz c-axis preferred orientation evidence used to drive the degree of non-coaxiality during deformation. The mean kinematic vorticity (Wm) value in the Tutak gneiss dome revealed contribution of 48% pure shear and 52% simple shear components. Detailed kinematic vorticity studies may allow this interpretation that the convergence between the Afro-Arabian and central Iran continental crusts is characterized by basement involvement during ongoing inclined dextral transpressional regime.
Vorticity
Simple Shear
Gneiss Dome
Zagros
Iran
2013
12
01
282
290
https://jtethys.journals.pnu.ac.ir/article_2776_f8cc3ae6830e55866316066b2d682104.pdf
Quarterly Journal of Tethys
JTethys
2476-7190
2476-7190
2013
1
4
An Investigation of Pb Geochemical Behavior Respect to Those of Fe and Zn Based on k-Means Clustering Method
A well-known algorithm of clustering is k-means by which the data are divided into k classes based upon a distance criterion. In the present research, by using k-means method for classifying data derived from exploration boreholes in the Parkam deposit, the optimum k has been calculated and then the data have been clustered and the relative geochemical behavioral characteristics analyzed. The criterion used for determining the optimum k ranged the number of classes from k=3 to k=10 and afterwards, analyzed derived classifications in order to choose the optimum k. Results showed that clustering with k=3 in case of Pb and Zn and k=4 in case of Pb and Fe were better than other classes number in each case and according to derived classification and above cases, increase in Pb grade is followed by increase in Zn grade and also There is an increase and subsequent decrease in Fe grade. Thus, it is possible to investigate the fluctuation of elements such as Cu or Pb with other elements existing in done analysis using suggested above method that can provide a very appropriate viewpoint in front of this industry decision makers.
k-Means
Clustering
Pb
Zn
Fe
Parkam
2013
12
01
291
301
https://jtethys.journals.pnu.ac.ir/article_2777_f44fd2a0e2269338578ffe6df6cd24c1.pdf
Quarterly Journal of Tethys
JTethys
2476-7190
2476-7190
2013
1
4
Geochemistry and tectonic setting of Maien Bolagh (Takab) alkali gabbros-NW Iran
Some small gabbro patches emplaced along the thrust fault with W-E trend in the vicinity of Maien Bolagh village at the HT/MP metapelites, a part of the Central Iran zone (near to Sanandaj-Sirjan zone). The coarse-grained dark gabbro samples consist of amphibole, clinopyroxene, plagioclase, minor quartz, titanite, and biotite. Gabbros have high potassic calc-alkaline to shoshonitic affinity. The highly incompatible elements concentrations (e.g. Nb and La) and Zr/Y and Zr/Nb ratios are similar to within plate gabbros. At the assorted discrimination diagrams the gabbros exhibit mostly non-orogenic resemblance. The geochemical characteristics show that the gabrros can be interpreted as melts formed from an enriched mantle in a passive rift position, during an extensional or transtensional tectonic
Gabbro
Maien Bolagh
Within Plate
Geochmistry
2013
12
01
303
314
https://jtethys.journals.pnu.ac.ir/article_2778_8943576a51bbcf7d7d9940450503d4a4.pdf
Quarterly Journal of Tethys
JTethys
2476-7190
2476-7190
2013
1
4
Application of Support Vector Machine method in Hyperspectral mapping of Ophiolite mélanges-a Case study from eastern Iran
The lithologies of regions, which located near the collision zone, are very different from other geology setting. Mapping in these areas needs extensive and exact studies and tools because of the variety of rocks, intensive tectonic uplift and complicated units. Hyperspectral sensor is one of the most advanced tools with hundreds of bands that each measures a very narrow range of wavelengths and continuous bands in visible and infrared spectrums, so it can identify various terrains despites with spectral similarities and complications. In present study, as the first survey of hyspectral data efficiency for separating ophiolite melange units in Iran, we applied spectral - based method of support vector machine classification method on Hyperion image, in east of Iran. Based on various laboratory- field studies, the lithology of studied area can be separated into five general groups (ophiolite series, metamorphic units, Oligocene - Miocene to Quaternary volcanic units, limestone and flysh units). In this region for calculation of processing results accuracy rate, some scattered locations and points were sampled according to field surveys. These samples were analyzed in microscopic section and by electron microprobe. Points of Grand though selected based on these field-laboratory studies for compute results accuracy rate. According to results, the average overall accuracy for all lithology has reached 52% in total colored- mélanges of the studied area at the east of Iran. The user accuracy factor of SVM method is highest for the lithology with more spectral separability. These coefficients are acceptable ratios in separation of ophiolites as actual complicated units.
Ophiolite
Hyper Spectral
Support Vector Machine (SVM)
Iran
2013
12
01
315
326
https://jtethys.journals.pnu.ac.ir/article_2779_4400cb6e5757178411b7454eadfb34eb.pdf