peyman afzal Articles List

List of Articles peyman afzal

Open Access Article
- Abstract Page
- Full-Text
1 - Delineation of hydrothermal alteration zones for porphyry systems utilizing ASTER data in Jebal-Barez area, SE Iran
Sara Fakhari Alireza jafarirad Peyman Afzal Mohammad Lotfi
10.30495/ijes.2019.664780

The Urumieh-Dokhtar Magmatic Belt (UDMB) is the host of many Iranian Cu porphyry deposits. The southern part of this belt, in the Jebal-Barez area, has been less investigated due to the mountainous and rough topography as well as some security confrontations. Porphyry d More

The Urumieh-Dokhtar Magmatic Belt (UDMB) is the host of many Iranian Cu porphyry deposits. The southern part of this belt, in the Jebal-Barez area, has been less investigated due to the mountainous and rough topography as well as some security confrontations. Porphyry deposits are associated with hydrothermal alteration zones, which can be mapped using the remote sensing data such as Advanced Space borne Thermal Emission and Reflection Radiometer (ASTER). The aim of this study was to identify and detect the alteration zones associated with porphyry systems using ASTER data in Jebal-Barez area, SE Iran. For this reason, seven scenes of ASTER level-1B data which cover the Jebal-Barez area, were pre-processed and then processed by band ratio, false color composite and Spectral Angle Mapper (SAM) methods. The result indicated the presence of extensive phyllic and argillic alteration zones. The argillic alteration is surrounded by border zones of propylitic alteration. Also, a massive granitoid intrusion in NW of the studied area was detected by SAM method and the color composite of 4, 6, and 8 bands of ASTER as a completely altered area (SF area) which strongly needs more detailed exploration and field inspections. Manuscript profile
Open Access Article
- Abstract Page
- Full-Text
2 - Geochemical exploration for Li in regional scale utilizing Staged Factor Analysis (SFA) and Spectrum-Area (S-A) fractal model in north central Iran
Farshid Koohzadi Peyman Afzal Davood Jahani Mohsen Pourkermani
10.30495/ijes.2021.685397

The main aim of this study was to outline the lithium anomalies by a regional exploration, at an area of 7800 km2, in Semnan province (north central Iran) using the Staged Factor Analysis (SFA) and Spectrum-Area (S-A) fractal model based on stream sediments and rock sam More

The main aim of this study was to outline the lithium anomalies by a regional exploration, at an area of 7800 km2, in Semnan province (north central Iran) using the Staged Factor Analysis (SFA) and Spectrum-Area (S-A) fractal model based on stream sediments and rock samples. Results derived via the SFA denote that Li was located in a factor as F2-4 with B, Cs, U and Rb which was utilized for calculation of the threshold values by the S-A method. The F2-4 data were classified by the fractal model for determination of the Li anomalies. Main anomaly for F2-4≥ 1.5 was situated in the SW and northern parts of this region. Furthermore, Li high grades of rock samples were correlated with main F2-4 anomalies. The main anomalies were correlated with geological particulars of Li mineralization types which represent that the main F2-4 anomalies associate with volcanic and tuff units in the SW part, and overlapped with clay minerals in the northern sector of this region. On the other hand, there are proper potential for Li mineralization which is demonstrated by this method. Manuscript profile
Open Access Article
- Abstract Page
- Full-Text
3 - Testing the Exactitude of Estimation Methods in the Presence of Outliers: An accounting for Robust Kriging
Shahrokh Paravarzar Nasser Madani Abbas Maghsoudi Peyman Afzal

Estimation of gold reserves and resources has been of interest to mining engineers and geologists for ages. The existence of outlier values shows the economic part of the deposits subject to the fact that don’t depend on the human or technical errors. The presence More

Estimation of gold reserves and resources has been of interest to mining engineers and geologists for ages. The existence of outlier values shows the economic part of the deposits subject to the fact that don’t depend on the human or technical errors. The presence of these high values causes a pseudo dramatically increment in variance estimation of economical blocks when applying conventional methods as such as kriging. Conventional approach such as replacing the upper limit (capping), log-normal and Median-indicator kriging have been somehow resolved the problem of estimations but they still have numerous drawbacks. The Zarshuran gold deposit is one of the nominated gold deposits in Iran that choosing the appropriate method is a great chance in the estimation procedure. Robust kriging is a method that is able to reduce the allocated pseudo kriging weights to the blocks surrounding with high value data, and correct them in a manner that not only enhance the accuracy of the estimation but also reduce the estimation variance to the reasonable level. In this method, the estimation can be implemented in the presence of outlier and do not need to eliminate, reduce or transfer the data to another space (normalization). In this paper an attempt has been made for estimating the gold in the ore used to be compared with capping high value method. Results showed that this method has a high efficiency and is able to run estimation properly and produces high precision due to the high value reduction. Manuscript profile

Current Issue

Published Issues

Menu

Browse

List of Articles peyman afzal