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Asadi, Hooshang 
  
  
406680! Line 1 05L 
4066800 
4066600 
4066400 406640! 
406620! 
4066200 
4066000 
MODEL PARAMETERS: 
Model Type Tabular 
4065800 406580 Depth 19.1 m 
Half width 7.48 m 
anse -Yellow rectangles show the donec Dip 54.7? 
location of modeled magnetic 
bodies on profiles Ol, 105L 
4065400 | and 255L 4065400 
  
4065200 4065200 
           
690600 590800 691400 582000 832200 
  
  
  
Figure 2. Analytical signal map of total ground magnetic intensity data at the Zarshuran deposit (a); 
and results obtained for quantitative modeling of the data for survey line 105L (b). 
4.1.2 Quantitative analysis 
Based on the qualitative analysis of the magnetic data, some elongated and circular strong magnetic anomalies over the 
Iman-Khan schist are interpreted as dykes or veins about 25-50m wide. The dimensions could probably be a bit larger 
but were affected by the smoothness of the data. 
An interactive magnetic anomaly modelling and inversion program (MAGMOD?3) was used to quantify the morphology 
of the subsurface magnetic bodies. The process of obtaining the “best fit” is carried out by adjusting the magnetisation 
and geometric parameters such as depth, dip, thickness, magnetic susceptibility, main position, and model type (tabular) 
that are applicable to a chosen geometrical model for a magnetised body. Three profiles, from the high magnetic 
anomaly area, were modelled using a TABULAR model The location of these profiles is shown on Figure 2a. 
The results obtained suggest that the anomalies present on all three profiles may reflect the presence tabular, highly- 
magnetic, bodies located at an average depth of 25 m, and dipping in a NE direction towards the core of Iman-Khan 
anticline. These magnetic bodies may be dykes or stock with intermediate-basic composition intruded into the 
basement schist. Details of the results obtained for survey line 105L are shown in Figure 2b, and results for all three 
profiles are summarised in Table 1. 
  
  
  
  
  
Parameters Line OL (00) Line 105L (10W) | Line 255L (25W) 
Depth 20.6m 19.1m 36.3m 
Dip 67.2? 54.7" 60.3* 
Half Width 12.8m 7.48m 11.5m 
Susceptibility 0.211 0.211 0.107 
  
  
  
  
  
  
Table 1. Results obtained from the three modeled magnetic profiles 
4.2 Geochemical data 
Exploratory data analysis, using statistical and spatial mapping methods, was first carried out for the analytical results 
of all 4500 samples analysed from the total grid covering both the Zarshuran district and its surroundings (Kiiza, 2000). 
For the purposes of the study described here, a subset of the data covering the area immediately surrounding the 
Zarshuran deposit was subsequently created. This subset covers an area of around 3km’, corresponding with the 
geographic limits of Figure 1, and contains 1214 samples. 
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International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. 85