ps out only in 
is principally 
rea (fig. 2). A 
continuously or 
/ plain, 
isured from the 
from LFC photo- 
sreted on radar 
>s occur in the 
partly parallel 
(Egypt). 
and SIR-B 
appear on the 
tot conclusive- 
he possibility 
owave penetra- 
atter response 
but could not 
ork. 
34°41'E) . The 
Ice swarms run 
central nephe- 
in two main 
5) . 
re seen cross 
mite body, so 
mporaneous or 
heline syenite 
sotopic dating 
ces were inter- 
; 336.1 km from 
ctional classes 
grams (fig. 6). 
sction which is 
compared with 
les with the 
52° from true 
ion is underre 
radar, as it is 
r to the radar 
iy of dike lin- 
the LFC photos 
through super- 
Dike-Lineaments interpreted from Radar and LFC 
Dike-Lineaments present only on Radar 
Dike-Lineaments present only on LFC 
Figure 5. Interpretation of dike lineaments in the 
Mishbeh area. 
ficial sand cover could have been of influence on 
the difference in interpretation of the two types of 
remote sensing images. 
Area 3: Southeast of J. Salala (Sudan 21°33'N, 
35°38'N). This area covers approximately 740 km^. 
The largest part belongs to the older batholitic 
granite, forming a low-lying eroded area with large 
part belongs to the older batholithic granites, 
forming a low-lying eroded area with large parts 
covered by sand and rock debris. In the most north 
ern part, a ring-dike complex of the younger granite 
occurs (fig. 7). 
The northwest corner and the hill in the south 
are made up of gabbroic rocks, whereas the south 
eastern corner of the area consists of metasedi 
ments and metavolcanites of the Nafirdeib Group. 
Most eastern corner of the area consist of metase 
diments and metavolcanites of the Nafirdeib Group. 
Most dikes occur in the older granite area. They 
form swarms which can be followed sometimes over 
tens of kilometers. A volcanic plug with a star-like 
radial outwards running set of dikes can be seen 
south of the ring-dike complex. 
Without taking the ring dike complex into consi 
deration, the total number of dike lineaments inter 
preted on the radar image is 201 for a total length 
of 283.8 km against a frequency of 173 for 251.4 km 
total length on LFC photographs. 
On close observation of the images, it appears 
that a few lineaments faintly visible on radar are 
absent on the LFC photo because of shallow sand 
coverage. 
Particularly in the direction 310°-330° and direc 
tion 0°-20°, a larger number of dike lineaments seem 
to occur on the radar image (fig. 8). 
Some of the dikes crossing the ring complex in 
approximately E-W direction and distinctly visible 
on the LFC image are absent on the radar image. No 
explanation can be given for their absence. The ring 
complex is equally well discernible on both LFC and 
radar images. 
Area 4: W. Odib (Sudan, 20°53'N, 35°50'E). This is 
Fig. 6a 
Figure 6. Rose diagram of dike lineaments in the 
Mishbeh area (a. SIR-B; b. LFC). 
a. h. 
Figure 7. a. SIR-B images of area 3 southeast of J. 
Salala (Sudan); b. LFC high contrast print. 
an area 20 by 25 km, situated west of Talania K. in 
a large sandy area where structures are only scarce 
ly discernible. The rocks belong to the gneissic 
Kashebib Group and to the older granitoids. A small 
number of discrete dikes are present on both images, 
running roughly E-W. There is not much differences 
between the two interpretations. Some are missed on 
the radar, others on the LFC photo. Also the meta- 
morphic trend direction of the Kashebib Group can 
be equally clearly seen on both images through the 
shallow sand coverage.