Earth and statistics
Volume:2 Issue: 1, Spring 2023

In the present research, grade modeling and ore reserve estimation of Yazd, Aliabad copper deposit were carried out using two high accurate non-linear geostatistical methods called log- kriging and multiple indicator kriging through Datamine. Variography of the transformed data in the variety of directions revealed that most empirical variograms are fitted with the spherical type of theoretical models, whereas the deposit has geometric anisotropy. To determine optimal block size of the deposit, kriging efficiency and kriging variance criteria were also employed obtaining the optimal block size of 20*20*7.5m. Based on validation of estimation results through cross-validation method for measured assay data against estimated values, determination coefficients were attained about 0.67 and 0.68 for log-kriging and multiple indicator kriging methods, respectively which are favorite results. Ore reserve estimation for various cutoff grades of 0.1, 0.15, 0.2, 0.25 and 0.3% showed that calculated reserve by indicator kriging method for cutoff grades of 0.1, 0.15 and 0.2% are less than log-kriging method about 6, 26 and 21%, respectively. The value for cutoff grade of 0.25% is equal for the both methods while in the case of 0.3% is about 13% higher. In general, the results of the indicator kriging method are more accurate due to the better resolution to separate ore deposit and waste. The results of the present study, can be generalized and used for all metallic ore deposits with geological and exploration conditions almost similar to Yazd, Aliabad copper deposit.

The purpose of this paper is estimation of earth velocity field using adaptive neuro-fuzzy inference system (ANFIS) in north-west of Iran. For this purpose, observations of 22 GPS stations are selected from the Azerbaijan local network. At the first step, the velocity field of these stations is estimated with Bernese GNSS software. Then, observations of 20 stations used for training of ANFIS with back-propagation (BP) algorithm. It should be note that the input vector of ANFIS is considered latitude and longitude of the GPS stations and the output is the velocity field (Ve , Vn). After the training step, estimated velocity field with ANFIS in two test stations, are compared and evaluated with the velocity field obtained from GPS. For a more accurate evaluation of the new model, all results are compared with velocity field obtained from the Kriging model. To analyze the error of the models, relative error and root mean square error (RMSE) is used. The averaged relative error of ANFIS and Kriging models obtained in the two test stations for the eastern component of the velocity field is 8.61% and 18.99%, respectively. Also for northern component, the averaged relative error is 21.84% and 28.51%, respectively. The results show the high accuracy of ANFIS model compared to Kriging in estimation of velocity field.

The study area structurally belongs to the Central Alborz tectonic range and is located 25 km south of Chalous city. The volcanic rocks in the region, composed of basalt, andesite, trachyandesite and dolerite, have been formed by fractional crystallization and, in some cases, contamination processes. In general, the rocks of the region are rich in LIL and LREE elements and devoid of HFS elements. Investigation of trace element and rare earth element ratios shows that basalts in the study area can be formed by partial melting of a peridotite garnet at depths and high pressures. Negative Ce anomaly, Nb positive anomaly, Pb/Ce ratio similar to sources OIB and variation in Ce / Pb ratio emphasize the role of continental and mantle lithospheres in the alignment of magmatic sources of volcanic rock elements in the study area.The two phenomena of delamination & detachment of the lithosphere and its immersion in the mantle (due to density difference) and transfer of dense lithosphere to the bottom (lower mantle) are related to the contamination of the magmatic source with the lithosphere for early magma rocks. The area's volcanism is known to be within the sheet.

The aim of this study is to analyze the geochemical characteristics of the Gachsaran formation sequence located in the border areas of Iran and Iraq. Due to its lithological diversity, this formation has various chemical properties in its lithological content. For this purpose, chemical and elemental properties were determined using XRF and ICP-mass techniques. The XRD technique was also used to identify the mineralogical composition and finally the amount of pollution caused by these elements was evaluated using statistical methods. The results of this study showed that the concentration of CaO, MgO, TiO2 and the concentration of two elements namely Cd and Sb in the sequence of Gachsaran Formation in the study area is higher than their average in the earth's crust. On the other hand, investigations showed that according to the CF pollution index, Cd and Sb elements with values of 1.52 and 2 show moderate pollution. Enrichment factor (EF) showed moderate contamination for some elements.    Three distinct groups were obtained according to the results of cluster analysis, each of Ti and Fe were classified as separate groups, and iron showed the greatest difference compared to other elements.

Stabilizing sand through sticky powder particles such as cement , plaster powder, lime, and reinforcing it with fibers causes that it can be used in constructing the roads, airports, stank, road embankments, and etc., It improves their capabilities. The aim of this research is to use the wastes of cartridge filter of water treatment machine in improving sandy soils( SP ,SM types)that it has not meet the needed quality expectations in geotechnical parameters, therefor the acts of sandy soil that stabilized with cement and reinforced with reused fibers of Cartridge tested and studied through particles grading test, soil compaction , and CBR( cartridge bearing ratio). Therefor in different tests used constantly 6% sand, and two cartridge fibers with 1.5 and 3 centimeters length in different dry density soil (%0, %0.2, %0.4, and %0.6). The testes results show that using fibers cause reducing maximum dry density of soil and increasing optimum moisture of the SM soil and increasing maximum dry density of soil and decreasing optimum moisture in the SP soil. Also using fibers of cartridge cause improving California bearing capacity in the SP and SM soils. Use of %0.4 fibers of cartridge waste left 1.5 centimeters result better than other percentage.

The gabbroic rocks in the southeast of Arak of the zone Sanandaj-Sirjan in are intruded into the Middle and Upper Cretaceous sedimentary units. The main gabbroic rocks varieties include olivine gabbro, monzogabbro, diorite, and monzodiorite. The main minerals phases in the rocks are plagioclase and pyroxene and the chief textures are sub-hedral granular, porphyritic, intergranular and poikilitic. Electron microprobe analyses on minerals in the rock samples shows that plagioclase composition ranges from labradorite to bytonite, with oscillatory and normal chemical zonings. Clinopyroxene is diopside, augite and salite in composition and characterized with alkaline nature. Thermometry calculations indicate temperatures of 750˚C to 950˚C for plagioclase crystallization and 950˚C to 1120˚C for pyroxene crystallization. According to tectonic diagrams and mineral chemistry studies, the rocks of the region were formed in an intercontinental environment(rift).