Syn-rift unconformities punctuating the lower-middle Cambrian transition in the Atlas Rift, Morocco

摘要: The Cambrian Tamdroust and Bab n’Ali Volcanic Complexes represent two magmatic episodes developed in the latest Ediacaran–Cambrian Atlas Rift of Morocco. Their rifting pulses were accompanied by accumulation volcanosedimentary edifices (dominated effusive lava flows former explosive acidic aprons latter) associated with active tilting uplift. Sealing their peneplaned horst-and-graben palaeotopographies led to onset distinct onlapping geometries angular discordances capping eroded basements ranging from Ediacaran Ouarzazate Supergroup Asrir Formation. Previous interpretations these as pull-apart or compressive events are revised here reinterpreted an extensional (rifting) context volcanism. record erosive unconformities, stratigraphic gaps, condensed beds patterns across traditional “lower–middle Cambrian” (or Series 2–3) transition must be taken into consideration for global chronostratigraphic correlation based on trilobite content.