The Tagoudite Formation marks a major shift in Liassic sedimentation, replacing the carbonate turbidites of the Ouchbis Formation with mostly siliciclastic layers. These layers alternate between gray and green sandstone, sandy marls, and siltstones, forming sequences up to 20 meters thick.[4] They show a decrease in grain size and an increase in marl content from bottom to top, with features like ripple marks and laminations. Microscopically, the turbidites are mainly fine silt, with varying amounts of quartz, feldspar, and carbonate detritus, and occasional pyrite. This formation suggests an open marine environment with sediment interruptions and materials coming from distant areas. It is widespread in the Central High Atlas, with thicknesses reaching up to 320 meters, and varies across different regions like Tounfite and Beni Mellal. In the Central Middle Atlas, sedimentation was interrupted by emersion before the formation's deposition.[4] The deposits of the Tagoudite Formation are mostly restricted to the central High Atlas, with a thickness of approx. 200 m in the northwest vs at 30–70 m in the southeast, but retaining around 200 m at center areas like Foum Tillicht.[5] More at the E it starts to disappear like at the Cirque de Jaafar, SW of Midelt or more at the E at Bou Redine Gorges, were the Agoudim Formation directly overlies the Pliensbachian.[6]
Small (-1 cm) rounded ridges and troughs wrinkle structures occur on the tops of fine-grained turbidite beds deposited rapidly in deep, low-light conditions, too deep for photosynthetic mats.[7] The wrinkles were likely formed by chemosynthetic microbial mats, sulfur-oxidizing bacteria (Beggiatoaceae, Thioploca spp., and similar Gammaproteobacteria) that thrive in dark, organic-rich sediments where chemical gradients provide energy. Frequent turbidity currents, high organic content (including woody debris), and sulfide-rich pore waters created ideal conditions for these mats to grow and for their textures to be preserved. Low animal activity due to toxic sulfide levels further enhanced preservation.[7]
Phytoclasts, spores, pollen and Tasmanites & Botryococcus algae indicate that the palaeoenvironment of the lower Toarcian Amellago area was likely proximal continental shelf with a high terrestrial input, and notorious influence of brackish water in the depositional environment.[43] This interval is numerically dominated by Classopollis, which usually accounts for more than 60.95% of the palynomorphs present.[43]
^Krencker, F.-N.; Fantasia, A.; El Ouali, M.; Kabiri, L.; Bodin, S. (2022). "The effects of strong sediment-supply variability on the sequence stratigraphic architecture: Insights from early Toarcian carbonate factory collapses". Marine and Petroleum Geology. 136. Bibcode:2022MarPG.13605469K. doi:10.1016/j.marpetgeo.2021.105469. ISSN 0264-8172
^Martinez, Mathieu; Krencker, François-Nicolas; Mattioli, Emanuela; Bodin, Stéphane (2017-01-01). "Orbital chronology of the Pliensbachian – Toarcian transition from the Central High Atlas Basin (Morocco)". Newsletters on Stratigraphy. 50 (1): 47–69. doi:10.1127/nos/2016/0311. ISSN 0078-0421
^Martinez, Mathieu; Krencker, François-Nicolas; Mattioli, Emanuela; Bodin, Stéphane (2017-01-01). "Orbital chronology of the Pliensbachian – Toarcian transition from the Central High Atlas Basin (Morocco)". Newsletters on Stratigraphy. 50 (1): 47–69. doi:10.1127/nos/2016/0311. ISSN 0078-0421
^Boulila, Slah; Galbrun, Bruno; Sadki, Driss; Gardin, Silvia; Bartolini, Annachiara (2019). "Constraints on the duration of the early Toarcian T-OAE and evidence for carbon-reservoir change from the High Atlas (Morocco)". Global and Planetary Change. 175: 113–128. doi:10.1016/j.gloplacha.2019.02.005. ISSN 0921-8181
^Löwner, Ralf (2009). "Recherches sedimentologiques et structurales à l'articulation entre Haut et Moyen Atlas et la Haute Moulouya, Maroc". Publications of the Universität Berlin. 356 (2): 2–212. doi:10.14279/DEPOSITONCE-2264. S2CID 132486463
^Krencker, F. N.; Fantasia, A.; Danisch, J.; Martindale, R.; Kabiri, L.; El Ouali, M.; Bodin, S. (2020). "Two-phased Collapse of the Shallow-water Carbonate Factory during the Late Pliensbachian–Toarcian Driven by Changing Climate and Enhanced Continental Weathering in the Northwestern Gondwana Margin". Earth-Science Reviews. 208 (1): 103–254. Bibcode:2020ESRv..20803254K. doi:10.1016/j.earscirev.2020.103254. S2CID 225669068
^Bodin, S.; Krencker, F. N.; Kothe, T.; Hoffmann, R.; Mattioli, E.; Heimhofer, U.; Kabiri, L. (2016). "Perturbation of the carbon cycle during the late Pliensbachian–early Toarcian: New insight from high-resolution carbon isotope records in Morocco". Journal of African Earth Sciences. 116 (2): 89–104. Bibcode:2016JAfES.116...89B. doi:10.1016/j.jafrearsci.2015.12.018
^Martinez, Mathieu; Krencker, François-Nicolas; Mattioli, Emanuela; Bodin, Stéphane (2017-01-01). "Orbital chronology of the Pliensbachian – Toarcian transition from the Central High Atlas Basin (Morocco)". Newsletters on Stratigraphy. 50 (1): 47–69. doi:10.1127/nos/2016/0311. ISSN 0078-0421
^Boulila, Slah; Galbrun, Bruno; Sadki, Driss; Gardin, Silvia; Bartolini, Annachiara (2019). "Constraints on the duration of the early Toarcian T-OAE and evidence for carbon-reservoir change from the High Atlas (Morocco)". Global and Planetary Change. 175: 113–128. doi:10.1016/j.gloplacha.2019.02.005. ISSN 0921-8181
^Pierre, A.; Durlet, C.; Razin, P.; Chellai, E. H. (2010). "Spatial and temporal distribution of ooids along a Jurassic carbonate ramp: Amellago outcrop transect, High-Atlas, Morocco". Geological Society, London, Special Publications. 329 (1): 65–88. Bibcode:2010GSLSP.329...65P. doi:10.1144/sp329.4. ISSN 0305-8719
^Krencker, F. N.; Fantasia, A.; Danisch, J.; Martindale, R.; Kabiri, L.; El Ouali, M.; Bodin, S. (2020). "Two-phased Collapse of the Shallow-water Carbonate Factory during the Late Pliensbachian–Toarcian Driven by Changing Climate and Enhanced Continental Weathering in the Northwestern Gondwana Margin". Earth-Science Reviews. 208 (1): 103–254. Bibcode:2020ESRv..20803254K. doi:10.1016/j.earscirev.2020.103254. S2CID 225669068