The effect of estimation methods on fractal modeling for anomalies’ detection in the Irankuh area, Central Iran

Document Type : Research Paper


1 بخش مهندسی معدن دانشگاه آزاد واحد تهران جنوب

2 Department of Mining Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran


This study aims to recognize effect of Ordinary Kriging (OK) and Inverse Distance Weighted (IDW) estimation methods for separation of geochemical anomalies based on soil samples using Concentration-Area (C-A) fractal model in Irankuh area, central Iran. Variograms and anisotropic ellipsoid were generated for the Pb and Zn distribution. Thresholds values from the C-A log-log plots based on the estimation methods revealed the presence of various geochemical anomalies within estimation variances which were compared in both methods. The comparison among the estimation variances for different geochemical anomalies based on the C-A fractal model indicated that the estimation variance is less in the OK method especially for extremely and highly Zn-Pb anomalies. The estimated variances for different Zn anomalies via OK and C-A fractal method are lower than fractal modeling obtained by IDW estimation. However, extremely and highly Pb anomalies due to OK method have estimation variances lower than IDW method. Based on the results, main Zn and Pb anomalies are situated in the NW part of the area.


Article Title [Persian]

اثر روش های تخمین بر روی شناسایی آنومالی ها با مدلسازی فرکتالی در منطقه ایرانکوه، ایران مرکزی

Authors [Persian]

  • پیمان افضل 1
  • مهدی رضایی 2
1 Department of Mining Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran
2 بخش مهندسی معدن دانشگاه آزاد واحد تهران جنوب
Abstract [Persian]

هدف از این مطالعه یافتن اثر روش-های تخمین کریجینگ معمولی و عکس فاصله وزن دار بر روی جدایش آنومالی های ژئوشیمیایی حاصل از نمونه های خاک برجا با استفاده از روش فرکتالی عیار-مساحت در منطقه ایرانکوه واقع در ایران مرکزی می باشد. نخست واریوگرام ها و بیضوی ناهمسانگردی برای مدلسازی توزیع عیار سرب و روی ساخته شدند. سپس منحنی فرکتالی براساس نتایج حاصل از این روش های تخمین ترسیم شده و واریانس تخمین هر یک از جوامع آنومالی تعیین شدند. براساس مقایسه بین واریانس های تخمین جوامع و آنومالی های گوناگون مشخص شد که واریانس های تخمین برای آنومالی های حاصل از روش تخمین کریجینگ معمولی کمتر از روش عکس فاصله وزن دار است. آنومالی های شدید و بالای سرب و روی حاصل از مدلسازی فرکتالی براساس روش کریجینگ معمولی دارای واریانس کمتر از آنومالی های متناظر ناشی از روش تخمین عکس فاصله وزن دار است. براساس نتایج حاصله آنومالی های اصلی سرب و روی در شمال غربی محدوده قرار دارند.

Keywords [Persian]

  • : عکس فاصله وزن دار
  • کریجینگ معمولی
  • واریانس تخمین
  • روش فرکتالی عیار-مساحت
  • ایرانکوه
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