ed in the
shown in
dy ground
| acquired,
is for the
esponding
Traction of
1e surface
a slightly
Xf shadow
actions of
1e to their
ident sun
with very
d areas. If
o the sur-
contrast it
¢ (Fig. 5),
"tween the
the slopes
d fraction.
on of sand
d in most
fractions.
ig. 6, top)
ments be-
‘ers. Areas
ear at the
surfaces.
NM.
<-11% -11- <-2% -2-2%
>2-11% > 11% masked
Fig. 4: Fractions of the endmember SHADOW
masked 0 - 20% 21-40%
41 - 6096 61 - 8096 81 - 100%
Fig. 5: Fractions of the endmember SAND
Because sand is an individual endmember but occurs also
In the stone pavement the obtained fractions can be ex-
plained in two manners: (1) the endmembers occur as sep-
erated areas or (ii) the stone pavement has a small
coverage with flintstones. In the southeast of the image is
à plateau that drains to the northeast. The drainage chan-
nels are filled with sand and some flintstones. These areas
show a large percentage of sand and a small fraction of
Stone pavement. In the areas between the channels there is
More or less dense stone pavement. The pixels in these
areas are unmixed as sand and stone pavement and the
fraction of stone pavement varies between 40 and 80%.
229
The nummulite-covered surfaces (Fig. 6, bottom) lie pre-
dominantly east of the lake. These areas are pediments
along the /nselberge covered by nummulites of the be-
drock. With respect to this endmember the spectral unmix-
ing is not unambigous and the areas could be nummulitic
limestone without gypsum. The investigation of a spe-
cimen from nummulitic limestone by x-ray diffraction
showed that nummulitic limestone does not necessarily
contain gypsum.
Areas with a large fraction of gypsum containing num-
mulitic limestone are rarely observed.
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B7. Vienna 1996