0000000000112649
AUTHOR
Abdelilah Tourani
Palaeoenvironmental analysis of the Early Triassic red beds in the northern part of Marrakech High Atlas and correlation with adjacent areas
National audience
Mid-Triassic to Early Liassic clastic/evaporitic deposits over the Maghreb Platform
Abstract The development of Triassic to Lower Liassic clastic/evaporitic series over the epicratonic Maghreb Platform is closely associated with the eastern opening of a Tethyan marine domain between Africa and Europe. West of the platform, Morocco became separated from North America in Late Triassic times by rifting along the axis of the Proto-Atlantic Ocean. In addition, NE–SW and ENE–WSW trending Atlasic half-grabens formed, essentially in Morocco, as part of a Late Triassic/Early Liassic Atlas rifting episode. This is the tectonic context in which the red bed to evaporite sequences were deposited. A first depositional pattern is illustrated by the areally extensive onlapping of Upper Tr…
Evidence of an Early Triassic age (Olenekian) in Argana Basin (High Atlas, Morocco) based on new chirotherioid traces
National audience
A new ichnofauna from the Permian of the Zat Valley in the Marrakech High Atlas of Morocco
Abstract A new ichnofauna from the Permian of Morocco is described in details: it is the first Palaeozoic ichnofauna from the Zat Valley in Marrakech High Atlas. The new tracksite was found in the Tighdouine region, in the middle-upper Permian of the Cham-el-Houa Siltstone Formation. An abundant and diverse ichnoassemblage composed of both protostomian (probably arthropods and annelids) traces and vertebrate tracks is recorded. The presence of protostomian burrows and traceways, associated with tetrapod tracks corresponds to the Scoyenia ichnofacies. Protostomian traces are ascribed to Diplichnites gouldi, Diplopodichnus biformis, Scoyenia cf. gracilis and Spongeliomorpha carlsbergi. Tetrap…
Evidence of an Early Triassic age (Olenekian) in Argana Basin (High Atlas, Morocco) based on new chirotherioid traces.
8 pages; International audience; New chirotherioid traces (Synaptichnium, Chirotherium, Brachychirotherium, Isochirotherium), are described in the Argana Basin (High Atlas of Morocco). Seeing that these ichnotaxa are frequent in the Triassic, their occurrence in outcrops formerly mapped as Permian (T2 Member) has required detailed sedimentological and paleontological studies of the fossiliferous site. These studies clearly show that the ichnite-bearing strata belong actually to the T3 Member of the “regional Triassic”, i.e. lower member of the Timezgadiwine Formation, the age of which was, in fact, unknown up to now. The description of these ichnospecies and their statistical comparison wit…
Cyclicity of Triassic to Lower Jurassic continental red beds of the Argana Valley, Morocco: implications for palaeoclimate and basin evolution
Abstract Cyclical playa deposits form a prominent part of the continental clastic succession of the Argana Valley, Western High Atlas of Morocco. The red beds formed in Triassic to Lower Jurassic times during rifting of the North American and African plates. Detailed stratigraphic work revealed asymmetrical, metre-scale cycles in mudstone-dominated successions that constitute the intermediate and upper portion of the basin fill. Sedimentary cycles commonly comprise ephemeral lake shales at the base, playa mudflat mudstones in the intermediate part, and both fluvial and aeolian sandstones at the top. Cycles of the Aglegal Member (T4) are mainly characterized by analcime-rich playa mudflat de…