Geology Reference
In-Depth Information
Fig. 4
The elements of the Geoheritage tool-kit showing the six steps in its application leading to assessment of types of geoconservation
(modi
ed after Brocx and Semeniuk
2011
). The map in Step 1 shows the simpli
ed geological regions of Morocco (after Michard et al.
2010
) and
the location of the Anti-Atlas
of geological features of various ages from Archaean to
Quaternary, from large- to small-scale, and varying in sig-
ni
The Anti-Atlas (AA) consists of a NE-SW-trending belt
of discontinuous Palaeoproterozoic to Neoproterozoic inliers
surrounded by Palaeozoic formations ranging in age from
Cambrian to Carboniferous and are well exposed in large
folded structures. These inliers from the SW to NE are Bas
Dr
cance from International to Local. The location of Mor-
occo in semiarid to arid environment provides excellent
exposures of many of these features.
Geology in the region strongly controls physiography.
For example, where the folding is isoclinal, there is devel-
opment of ridge-and-valley topography and linear ridges,
and fold limbs develop linear ranges. Lithology plays a
major part in the style of drainage and development of
topography. Physiographically, the geological regions, their
lithology, and the surrounding climate and earlier Quater-
nary climates have been and are the in
Akka, Igherm, Sirwa, Igu-
erda, Zenaga, Bou Azzer, Saghro and Ougnat (see Fig.
5
,
and Thomas et al.
2004
)
The AA is separated from the northern regions (Meseta
and High Atlas) by a major north-east trending fault, the
South Atlasic Fault which extends from the Atlantic Ocean
to Gab
â
a, Ifni, Kerdous, Tagragra d
'
s in Tunisia. It is classically subdivided into two
main domains by the Anti-Atlas Major Fault (AAMF) (Le-
blanc and Lancelot
1980
) and consists of variable stratig-
raphy, expressed in lithologically diverse formations
(Leblanc and Lancelot
1980
; Saquaque et al.
1989
; De Kock
et al.
2000
; Thomas et al.
2002
; Walsh et al.
2002
; Inglis
et al.
2004
; Gasquet et al.
2005
; Burkhard et al.
2006
;
D
è
uences on develop-
ing the landforms. The major geological regions (whether
folded and faulted rocks corresponding to tectonic belts,
intrusive batholiths, or sedimentary basins) in
uence the
development of the major physiographic regions, each with
their own megascale geomorphic expression and relief. Thus
the physiographic regions of the Rif, Meseta, High and
Middle Atlas, Anti-Atlas, and Saharan Plateau largely cor-
respond to the geological regions (Choubert
1963
; Michard
1976
; Piqu
Lemos et al.
2006
; Raddi et al.
2007
; Soulaimani and
Burkhard
2008
; El Hadi et al.
2011a
). The Palaeoproterozoic
and Neoproterozoic formations are affected by Eburnean
and/or Pan-African orogenies, dated at circa 2 Ga and
700
'
1994
; Chevalier et al.
2000
; Gresse et al.
2000
;
Michard et al.
2008
; Soulaimani and Burkhard
2008
; Fig.
5
).
é
600 Ma, respectively (Leblanc and Lancelot
1980
;
-
