Geology Reference
In-Depth Information
Fig. 4 a
The ancient Berber houses in the village of Tazekka
represents a superb example of integrating traditional building with the
rocky (here the Tafraoute granite)
mismatching elements are rather frequent in the contemporary archi-
tecture (note the white frame on the
lower
-
right
side of the photograph).
b
Prehistoric rock carving of a gazelle near Tazekka
landscape. On the contrary,
Fig. 5
The PII quartzites
conform the impressive cliffs that
anks the Ameln valley to the
north (north of Tafraoute).
a
The
famous Lion
'
s head, another
natural sculpture on top of the
quartzite cliffs.
b
View of
Oumesnate, one of the many
small picturesque towns in the
Ameln valley, with the typical
adobe constructions only
disturbed by a few modern
concrete houses and parabolic
antennas
3.4
Izerbi Plain (IP)
Piqu
2004
). The tectonic structures outcropping in the
metamorphic Eburnean basement rocks (folds, crenulations
and kink-bands, e.g. Fig.
7
b) are of special interest and
relevant for the understanding of the Pan-African orogeny.
Another remarkable feature in these basement rocks is the
widespread presence of swarms of ma
é
A singular characteristic of this geozone concerns the con-
trasting landforms of geological predominance. The Izerbi
plain, an extensive semi-desertic
atland conformed by
extremely eroded rocks of the Eburnian basement, is bor-
dered to the north by the irregularly shaped mountain cliffs
that consist of steeply dipping Neoproterozoic PII quartzites
(Fig.
7
a). However, the most remarkable aspects of this
geozone concerns Earth processes heritage. The contact
between both Eburnean and PII units is represented by an
east-west trending Pan-African shear zone (the Tasrirt-Ta-
hala shear zone). Together with the previously mentioned
Ameln Valley shear zone, northwards in the Kerdous massif,
both shear zones represent the major structural features in
the Kerdous inlier
c (mainly doleritic)
dykes (Fig.
7
a; Carreras et al.
2006
; Casta
ñ
o
2010
). These
ma
c dyke swarms are also common in other adjacent inliers
(e.g. Ikenne
1997
;Ha
d
1999
), but are especially well
exposed in Kerdous inlier, where many intriguing internal
and marginal deformation structures in contact with the
hosting metamorphic rocks are displayed. These dykes are
almost exclusively intruded into the Eburnean metamorphic
and granitic rocks, although geochemically af
ne sills were
found in the PII materials (Hassenforder
1987
). A debate still
remains regarding whether there is one or more magmatic
(Hassenforder
1987
; Soulaimani and
