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Chapter 12 Basin Evolution and Sediments
~ TRANSPORl OF CLASTICS
~ JNGRESSION OF SEA
INVERSED RIFT
OF HIGH ATLAS
TERTIARY
N
BAJOC,fBATHONIAN
d
ALTITUDE UP TO
4000 m A.S.l.
STEEP-ANGLE
OVERTHRUSTING
L ATE TRIASSIC -EARLY JI,JRASSIC
RED _BEDS , BASALTS, AND
EVAPORITES (BLACK)
IN WESTERN HIGH ATLAS :
BEDS OF MID-CRETACEOUS
TRANSGRESSION :t PALEOGENE
c
S
SHEL F
"""t:i2i~;lZ~lI!a:S;;:;;::-- CONTINENTAL BEDS
CARBONATES
SHALLOWING-UPWARD
N.
..... ~ ...... ""GREEN MARLS
E TRIAS.SIC-EARLY lIASSIC
.REDBEDS, EVAPOR ITES,
BASAUS
b
ORAN
MESETA
SHELF
N.
CENTRAL HIGH
S. SHELF
SAHARAN
CRATON
DEEP
Fig. 12.6a-c. Evolution of High Atlas rift zone from
extensional to compressional (transpressional) phase.
a Paleogeographic reconstruction for the late Triassie, overview. (Beauchamp 1988). b Simplified cross
section of High Atlas rift zone showing possible interpretation of structural features according to simple
shear model with low-angle detachment. c Idealized
stratigraphie cross section drawn on a DomerianToarcian datum (peak of transgression). Note that
S. DEEP
younger sediments (Middle Jurassie, in the western
High Atlas, to Turonian) indicate continued subsidence (b and c after Warme 1988). d Simplified
block diagram of ,present structure of High Atlas
caused by compresslOn (transpression ?) and uplift of
the central rift zone (inverted failed rift). (After Stets
and Wurster 1982; Wurster and Stets 1982;
Froitzheim et al. 1988)