Asadi, Hooshang
reflect cross-cutting faults, or geological contacts across which there are abrupt changes in gold content. Features
interpreted from these plots are summarised in Figure 4.
NC "—— High geochemical anomaly
4066200
vide "^ Low geochemical anomaly
4086800 |— : DE >
4066400
Contacts of mineralized
units
"" Discontinuity
LN VL Magnetic lineament
4066200
4065000
Le NH
4065600 N
AP MW LU) M-—CD M NJ
LANE OWENS (OT NÉE
N Nf ^
N "d
4065400 = 7
4065200 v
890500 890800 621000 691200 691400 681600 891600 582000 692200
690600 690800 691000 691200 691400 691600 691800 692000 692200
Figure 4. Colour shaded contour plot for gold in soils at the Zarshuran deposit (left); contours shown are at regular
log. ppb intervals. Features interpreted from the gold soil geochemical maps, and processed ground
magnetic data, are summarised in the map shown on the right.
4.2.2 Quantitative analysis
Results from follow-up drilling done in the Zarshuran area in 1994 and 1995 were available from 13 drillholes. A
comparison of these results with those obtained from the soil geochemistry in the same area was used in order to allow
quantitative predictions of resource potential to be made using the soil geochemical results.
Log probability plots of the drillhole data again indicates the presence of two distinct populations (Figure 3).
Comparison of the populations inferred from the soil and drillcore samples suggest that whilst more or less identical
low grade populations can be inferred, there is a strong difference between the high grade populations (Figure 3). The
high grade population in the soils shows a significantly higher average gold grade than that for the drillcore samples,
although similar variances are indicated. This is interpreted as reflecting strong residual enrichment of gold in the soils.
The relationship indicated in Figure 3 was used to predict in situ gold grades from the average present in the defined
soil anomalies (Figure 4), as discussed below.
4.3 Three-dimensional interpretation
Based on the results obtained from the interpretation of the available spatial data sets, several important features of
direct relevance to 3-d geological interpretation for resource estimation have been identified. The main features of
relevance are summarised briefly below:
a) The main NW-SE stratigraphic trend is confirmed by linear anomalies identified in both the geophysical and
geochemical data (Figure 4).
b) Several NE-SW linear features, which terminate or displace the stratigraphic trends, are inferred to represent faults
(Figure 4).
¢) Quantitative interpretation of the peak magnetic anomalies indicates the presence of one or more tabular magnetic
bodies, within or on the contact of the Iman-Khan schists, which dip NE at around 60 degrees (Figure 2).
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. 87
