International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B4. Istanbul 2004 
expressed this boundary with a continuous line on the map. 
Second type of formation boundaries defined as dashed lines on 
the map. Those are “probable” boundaries and they represent 
the expected place of the boundary which can not directly be 
observed in the field. Sometimes geologists do not finish the 
formation polygons because of the field conditions or because 
they are out of area of interest. Those types of unfinished 
formation polygons which are the third type of boundaries are 
problem while converting digitized data into the GIS. In order 
to define the formation as a polygon, those types of boundaries 
were digitized also and expressed as *Not Exist" in the attribute 
table. The last type of formation boundaries in our geological 
maps are “Faults”. 
  
Formation A 
Fault 
Fault Boundary 
      
  
  
Definite Boundary 
Not Exist Boundary 
Definite Boundary 
  
  
Formation B , ^ 7 
mm Formation A 
Fault Boundary Probable Boundary 
  
  
  
Figure 1. Types of formation boundaries 
As a result all of the formation boundary types are shown in 
table 1. 
  
[ Table Name | Baundary | 
  
  
  
  
  
Field Status 
Name 
Entered Attributes | Definite 
Probable 
Not Exist 
Fault 
  
  
  
  
Table 1. Attributes of formation boundaries entered during 
digitization 
2.2.2 Structural Features 
Structural features of the geological maps were expressed in 
three items. Those are faults, folds and  dip-strike 
measurements. 
The direction of lines expressing structural features contains 
information. For that reason, direction of the lines is also 
considered during digitization. For example, a right lateral 
strike-slip fault is always digitized from left to right. By this 
way, cartographical symbols can be placed by scripts within 
GIS. 
2.2.2.1 Faults 
The faults (Fig. 2) that were indicated as straight lines on the 
map are observed in the field. Those types of faults are named 
as “Definite Fault”. Faults indicated with dashed-lines are 
named as “Probable Faults”. 
  
  
  
Definite Probable 
—>- Right Lateral Strike-Slip -Z==~ Right Lateral Strike-Slip 
—— Loft Lalor) Strike-Slip 2... Left Lateral Strike-Slip 
TT A LT" 
-4 A A. | ow Angle Thrust -4.4.4. Low Angle Thrust 
AAA High Angle Thrust -A.^.A. High Angle Thrust 
LU Normal -L..L..L... Normal 
T Nomal 24:5 313 7m zt Normal 
Y Normal Vv Normal 
  
  
  
Figure 2. The symbols of faults represented on the geological 
maps and their meanings. 
2.2.2.2 Folds 
Folds are structural features which are represented on 
geological maps by their axis. If a fold is observed in the ficld 
and/or using other geological properties it is named as 
“Definite” and represented by a straight line on the map. On the 
other hand if the axis is not definite at the field, it is represented 
by dashed line on the map and it is named as “Probable” (Fig 
3). 
  
Definite Probable 
.  Anticlinal ^  Anticlinal 
Y Synclinal Y Synclinal 
v Overtumed Anticlinal Overtumed Anticlinal 
ia  Overtumed Synclinal ia Overtumed Synclinal 
  
  
  
Figure 3. Symbols of fold axis represented on the geological 
maps and their meanings. 
As a result while digitization of structural features all of the 
entered attributes are shown in table 2. 
674 
  
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