Azilal Formation

Azilal Formation
Stratigraphic range: Latest Pliensbachian-Early Aalenian Domerian-Scissum
Panoramic of the High Atlas on Azilal
Type	Geological formation
Sub-units	Toundute Continental Series Wazzant Formation
Underlies	El Mers Group Bin el Ouidane Formation
Overlies	Argane Formation Azmerai Formation Trafraout Formation
Area	High Atlas
Thickness	From a few meters to 800 m
Lithology
Primary	Claystones
Other	Red Clay, sandstone, conglomerate, Gypsum, Red marl
Location
Coordinates	31.3°N 6.6°W / 31.3; -6.6
Approximate paleocoordinates	26.6°N 3.4°W / 26.6; -3.4
Region	High Atlas
Country	Morocco
Type section
Named for	Azilal
Named by	Jenny et al.
Location	Azilal
Year defined	1985
Thickness at type section	~340 m (1,120 ft)
Azilal Formation (Morocco)

The Azilal Formation, also known as Toundute Continental Series and Wazzant Formation, is a geological unit in the Azilal & Ouarzazate provinces of the High Atlas of Morocco, that cover the Latest Pliensbachian to early Aalenian stages of the Jurassic Period. It is a terrestrial deposit which overlies marine dolomites of equivalent age to the Budoš Limestone of Montenegro or the Marne di Monte Serrone of Italy. Dinosaur remains, such the sauropod Tazoudasaurus and the basal ceratosaur Berberosaurus are known from the unit, along with several undescribed genera. The Units inside the group have been considered individual on the past, being a division of the so-called "Couches rouges", and subdivided by a supposed geological scale. The strata of the group extends towards the Central High Atlas, covering different anticlines, and topographic accidents along the range of the Mountains. Although new studies have suggested that the strata is coeval in age, and should be referred to as a unique unit. The formation is best assigned to an alluvial environment occasionally interrupted by shallow marine incursions (tidal flat setting) and marks a dramatic decrease of the carbonate productivity under increasing terrigenous sedimentation. The Azilal Formation consists mainly of claystones rich in continental plant debris and laminated microbial facies. The toarcian High Atlas is divided in 5 units: the continental layers with parallic deposits belong to the Azilal, along the shoreface layers of the Tagoudite Formation and Tafraout Formation, both connected with the offshore Ait Athmane Formation and the deeper shelf deposits of the Agoudim 1 Formation.

Strata

The layers at Azilal are the main sedimentary unit inside the Group. It was the first named unit, and one of the most studied since the 1980s. It consists mostly on a succession of detritic rocks with Red Marls, deposited on an alluvial environment occasionally interrupted by shallow marine incursions, a Mudflat setting. The lithology of the unit recovers also a Claystone-dominated interval, incised by metric dolomitized beds of Mudstones, Peloid-rich Packstones, Ooid-rich Grainstones, and Polymictic Conglomerates, all rich in Terrestrial plant debris (Mostly Ferns debris), with faunal content very poor and mostly dominated by microbial facies. The Jbel El Abbadine zone provides the biggest outcrop of the parts of a Calcareous massif, with strata of the Late Lias. Mostly of this strata is recovered inside the Azilal Formation, with a succession of seashore and inland deposits. Several seismic events located on the Tethian realm where the main genesis of the Tectonic activity locally, with emerged strata from the Paleozoic, that was eroded due to the local conditions. Along with the Wazzant Formation, the two units and Azilal characterize the outer borders of the Atlas Gulf during the Toarcian-Aalenian. The Formations are a connected continuation, with the presence of abundant marine and Brackish common material, along with the fluvial facies of the Wazzant formation. On the disposition of the facies from north to south and from west to east, a lateral passage shows from coastal to fluvial sedimentary deposition, with foreshore facies and beach facies. The Azilal Formation was deposited on an environment more influenced by marine sedimentation than the Wazzant Formation. Along the main Toarcian strata, there is a predominantly presence of basinal facies, dominant and quite uniform, leading to know a possible deposition controlled by thermal subsidence, generating a deposit of more than 5000 m of marls and calci-Turbidites accumulated until the end of Bajocian. Part of the marine deposits of the Azilal Formation are a continuation of the common Lithiotid-Coral reef deposits from the Toarcian Central High Atlas. Those reef-related facies start mostly on upper Pliensbachian-lower Toarcian boundary, and are commonly filled with Lithioperna, Cochlearites, and specially Phaceloidea corals that built reefal Framestones extended on lateral Biostromes. The Azilal Formation coralline strata is nearly unexistent, compared with other formations of the High Atlas, showing a decreasing on these kinds of habitats as the Aalenian period started. The aftermath of the Toarcian Oceanic Anoxic Event is also highly present on the marine strata of the formation, with the so-called Toksine Section, a succession of near shore marine strata disposed along the Toarcian boundary, where its last 40 m belong to the lower part of the Azilal Formation and are composed of dolomitized Mudstones and ooidal Grainstones, that show a slowly recovering a low-depth nearshore marine environment after in the Pliensbachian-Toarcian boundary a dramatic Tethys-wide collapse of the Neritic Carbonate System happened. There is also a local record of a Cold Snap, where the Akenzoud section, that has 182 section meters on the Azilal Formation, and shows that after cold event that affect the local waters, related to the Karoo & the Atlantic Rift volcanism the present Brachiopods, based on their preserved oxygen isotope data show that warm seawater temperatures re-established during the early Late Toarcian. The study of this section also revealed that the beach to nearshore deposits of the formation were part of a storm-dominated platform. On the related strata there is a wide presence of storm events, as after the Toarcian AE and the rising of the temperatures on the late Toarcian the presence of ubiquitous storm deposits appear correlated to the warming of sea-surface temperatures, pointing to an intensification of tropical cyclones during the T-OAE and other warmer periods on the Toarcian.

Stratigraphy of the Azilal Formation on the Mizaguène Hill (Termier, 1942)

Unit	Lithology	Thickness (metres)	Fossils
1)	Sandstone with a wine tone, composed by grains that range from 1/4 to 1 mm	0.2 m	Non present
2)	Red Pelites: these levels form the horizontal table of the Summit	4–5 m	Non present
3)	Red Sandstone composed by grains of 1/2 mm in benches of 10 to 20 cm	1 m	Non present
4)	Lithified red Pelite	2 m	Non present
5)	Coarse red sandstone (pebbles of 1 cm with other pebbles, many less than 2 to 3 cm); a level with a clear escarpment, from 80 cm to 4 m on the southern flank of the hill and climbs a beautiful entertained estratification, sculpted by erosion	0.8–4m	Non present
6)	Sandy red pelites	2 m	Non present
7)	Red pelites passing through Leafy sandstone	2 m	Non present
8)	Sandy red pelites	8–10 m	Non present
9)	Yellowish marno-conglomeratic sandstone, with bones and remains of plants, which, when not transformed into Lignite, show traces of preserved structure; this lenticular layer, which does not seem to exceed 80 cm, locally contains regions of sandstone and Calcite Geodes	0.8 m	Eusauropoda indeterminate Microvertebrate debris Lycophyta Debris Fern Debris Selaginellaceae-like leaf fragments Cycadales Debris
10)	Bluish sandstones of fairly variable composition: fine particles, with grains of 0.5 mm, thar contain various minerals such as Angular Quartz, Plagioclases, abundant Chlorite, clastic Andalusite and Iron Oxide; The coarse parts, the grain reaches 2 mm, consisting of often hexagonal Quartz and Moscovite, over Cemented Calcite; on the whole, there is an arched afloration of not only of a solid mass of Granite, locally of Granulite, but decorated with its metamorphic mass; Overall, this level has surface impregnations of Malachite	2 m	Microvertebrate debris Selaginellaceae-like leaf fragments Fern Debris
11)	Yellowish marno-conglomeratic Sandstone, like the level 9, also containing abundant bone material.	0.7 m	Microvertebrate remains Lycophyta Debris Fern Debris
12)	Pelite and Bluish sandstones	0.7 m	Fern Debris
13)	Very finely lit bistrated limestone, with green and purple grains	0.2-0.3 m	Indeterminate, present
13)	Red, Bluish and Green Pelites, disposed on lenticular bands over yellow Breccia marls, parallel deposited with bodies od Calcite	10–15 m	Indeterminate, present

Geology

The Central High Atlas of Morocco is part of a double-vergent mountain belt that originated due to Cenozoic shortening and inversion of a rift that developed between the Triassic-Jurassic periods. The structure of the High Atlas can be defined by two main groups of faults, thrust and oblique-slip faults, that occur from W-E to NE-SW. The presence of tectonic inversion in the Atlas Mountains has shown that are a intracontinental mountain belts that appeared from the uplift of pre-existing rift systems, where here is represented by a major rift system (~2000 km) originated on the Mesozoic, that was later uplifted and inverted in the Cenozoic. The impact and convergence movements of the African-Iberian plates after the Mesozoic end with an inversion of the previous deposited strata, transporting the sediments of that and forming new low angle thrusts. Triassic, Jurassic and Cretaceous strata are confined within basins controlled by the extensional structures of the Mesozoic rift. The Jurassic basins can be grouped into two main provinces located on either side of an emerged Massif Ancien: west, where the basin was open to the Early Atlantic, being related to its passive margin, and east with several epicontinental troughs connected to the Tethys Ocean. Across the Toarcian-Bajocian strata, there was a great deposition of marine shales as marls, calciturbidites and reefal limestones, that were accumulated in the Central High Atlas, while on the west margin around the Massif Ancien terrestrial, specially fluvial sedimentation dominated. The present Red Beds of Azilal indicate various marine transgressions across the Toarcian-Aalenian boundary, after ending its sedimentation on the Bathonian. A initial tectonic event on the Triassic-Jurassic boundary led to the formation of the Tigrinine-Taabast pull-apart basin. Following this event a major extensional tectonic activity (derived from the second Pangea rifting) occurred towards the end of the Pliensbachian and beginning of the Toarcian. This second major tectonic event developed towards the E-W- to NE-SW, reactivating trending normal faults, what led to the drowning of the Lower Liassic carbonate platform and the predominance of marls during the Middle Liassic to Toarcian.

Rift Vulcanism

Along the High Atlas Triassic-Jurassic boundary, and until the Bathonian stage of the Middle jurassis, there is a record on vulcanism locally on the succession of different local formations, such as the own Azilal Formation and other, as the underlying Argane Formation. Mostly of the north-african Rhaetian-Bathonian volcanic events are related to the open of the Atlantic Ocean, with parallel records found on the North American coast and other zones such as Mexico. On some locations, such as Haute Moulouya, it is even possible to delimitate the transitions between the several Volcanic events that happened locally along the post Triassic-Jurassic boundary (Belonging to the Tizi-n-Ghachou Formation). Mostly of the effects of the volcanism occur on the main emerged terrestrial deposits, where some of the nearshore strata was turned down du to tectonics, and hit after by volcanic eruptions of different grades, leading different kinds of volcanic strata.

The origin of the Volcanism is related with the Geography of the zone. On the Hettangian-Sinemurian there was a post-rift carbonate platform developed in the Atlas area that emerged older marine strata. On the Middle Toarcian, subsiding basins appeared which isolated the Mesetas and Precambrian and Paleozoic massifs. Alkaline magmas overflowed the created Central High Atlas basin. This basins were fault-bounded basins, with variations of the sedimentary thicknesses and intra-formational breccias related to major blocks. The Magmatic Province of the Atlas influenced the deposition of the main strata, where the Terrestrial settings of some Formations (Including Azilal) was disposed over a series of cut extensional faults depicting a mosaic of horsts and grabens oriented to the East, North-East and East-West, with the Middle Atlas among the main areas of subsidence. The Central Atlantic Magmatic Province continue to erupt around the Pliensbachian–Toarcian event ~183 Ma ago, overlapping the eruption of the Karoo–Ferrar igneous province. Middle-Late Toarcian Vulcanism was present but on smaller extension, as prove the Toundoute Continental Series Member.

Toundoute Continental Series

The Toundoute Continental Series lithology is divided into 5 units from D to H, (A-C represent the units of the underlying marine dolomite, with C representing a transition to terrestrial environment). The Toundoute sector recovers only the Middle to Late Toarcian, with an atypical paleogeographic element, located on the route of the South Atlas Accident, with several changes on the structure leading to show the instability of the deposit area. The formation shows the transition from carbonates to a series of continental detrital sediments, with palynomorphs and fossils. The presence of volcanic sedimentation is one of the most important aspects on the Toundoute strata. The fragments can come from a reworking of Triassic basalt flows, with most of the products homogeneous, probably of trachyandesitic nature. The deposits are young, probably related to the magmatism of the Middle Jurassic, with inflows probably contemporary with and related to eruptions, as in the case of many current volcanoes, in the form of dense flows. The tectonic processes on the high Atlas probably lead to most of the volcanic manifestations locally.

Stratigraphy

The formation is subdivided on several stratigraphic levels, starting with the so-called facies of term A, composed by Gypsum and Salt, from Triassic age, supported by the presence of Volcanic Intercalations of basalt. Above that, there are carbonates of term B alternated at the first with Dolomites, Pelites and Limestones along with Marly-Silt crimes with plant debris, which had regular influence of a marine environment. That is proved by the presence of ooids, oncoliths, debris of molluscs and benthic foraminifers, being dissolved and recrystallized as sparite. The third level shows a transition between marine and continental deposits, through carbonate palustrine levels and Caliche horizons, being continental layers superimposed in stratigraphic continuity over the marine carbonates of the lower Lias (Sinemurian-Hettangian). Those continental layers are rich in Coarse Volcano-detrital episodes as result of a sedimentary process of high sedimentation rates, where the strata, including the deposit with Dinosaur fossils, were deposited on a short time interval, where Middle Jurassic Bajocian-Bathonian carbonate levels, frequent within the Atlas domain, do not exist not in Toundoute. The sedimentation on the Toundoute member have some characteristics, such as lenticular channels with Sieve-Conglomerate of ~5 m thick (≤ 5m) for visible decametric, composed of several materials, like Volcanic products, as blocks of volcanic rocks such as sands made of Feldspars, black ferruginous grains from the surface of volcanic rocks on dry periods, siliceous green fragments from post-eruption processes (veins, microgeodes, nippled concretions), Limestone debris with traces of roots and cracks, where in some parts traces dark fine bushy algae filaments are still visible, similar to the genus Girvanella blue-green algae. Other materials include schist and Vein Quartz, without bone and wood debris with a good cellular structure. The Floodplain-like deposits are divided in two parts, with hard Limestone nodules, pink or brick and very irregular, typical of profiles of Calcimorph Soils formed on climates with pronounced dry phases. Those nodules had a visible reorganization in the channels, as a result of erosion of the alluvial plain by the fluvial network. Finally there are present interlays of fine sandstone often laminated that mark the Flood facies from channels in period of flood, being composed only by plagioclase Feldspars and in a lesser proportion of orthoclases, along with small ferruginous grains or fine silts of quartz. There is documentation of warm climatic conditions locally, that alternating wet and dry periods, as is seen on the other formations gave rise to soils with differentiated limestone profiles, such as Pedogenetic Nodules or Caliche. The accumulation in the channels from calcimorphic soil profiles shows the presence of an active erosion on soils with probably sparse vegetation.

Stratigraphy of the Toundoute Continental Series

Unit	Lithology	Thickness (metres)	Dinosaur fossils
Alluvium	Holocene conglomerate
H	Clay-sandstone series	≥ 100
G	Clay-sandstone series, with gypsum layer present at the top, just below this a second dinosaur bearing horizon is present with very similar lithology to unit F.	50	Tazoudasaurus, Berberosaurus
F	Greenish grey clay-marl, detrital gravel to pebble-sized clasts with lignite and bones.	≤ 5	Present, indeterminate
E	Alternation of red-brown clay, fine sandstone and sandstone coarse conglomerates	100
D	Clay, fine sandstone and conglomerate, large volcanic rocks present.	80

Wazzant Series

The Wazzant series recover a variation on the sedimentary process observed on the older Azmerai Formation. It is characterized by the presence of abundant Quartz sediments, along with the presence of red clay. Along the meridional border of the Guettioua Formation, on the same stratigraphic tendence is developed a red Sandstone-Pelitic deposition, that changes from Quartzo-Conglomerates to grains and fragments of Quartz, disposed with liassic calcareous strata. is equivalent to the main Azilal "Marnes Chocolat". The main sector occurs near Acfarcid, with an exposure of ~800 m, recovering the most detritic sector. Along this expossure, the Wazzant member appears at the right lateral, along massive calcareous dolomites, over the latest Pliensbachian strata, where the lower Toarcian strata is missing. The Wazzant facies never exceed 50 m, getting its maximum exposure at the north of the Guettioua Formation. The facies of the formation follow a deposition typical of Alluvial Plains. It also recovers a succession of reddish brown tones predominantly terrigenous: Conglomerates, sandstone, clays related to paleosoils, along with dolomitized limestone. The Wazzant formation has a notorious proximal character compared to the Azilal formation. These deposits fill in many small tear pools in the Atlas Central. Only its the stratigraphic framing allows to locate the formation in the Toarcian interval. The predominantly terrigenous deposits of this formation suggest they were deposited in continental setting, influenced by at least 6 different river channels, that trace its path to the Atlas Gulf. On the Toarcian-Aalenian transgression, the High Atlas domain experienced a long process of extension and rifting, recorded by the presence of marine carbonates and shales, found on the Wazzant Formation Beds. It is related to the formation of the Atlantic Rifting to the west and of the formation of the Tethys Ocean to the north. The fluvial system of the Wazzant formation was led by a bigger river, and several minor freshwater currents, that were probably temporal and linked to rain seasons. The presence of many dwarf lamellibranchs in the south of Azilal, the fine oblique stratifications, the floating plants and imprints of raindrops demonstrate that these two formations are of Aquatic origin, may be lagoonal, with temporary emersions. Several fish fossils have also been found.

Environment

The Azilal Formation represents mostly continental deposits with layers deposited under arid to humid conditions, yet also includes siliclastic intrusions in coastal sectors. This last ones likely look similar to modern places such as Kedrodasos Beach in Greece

The Azilal Formation represented diverse settings on the coast of the Toarcian Atlas basins, including continental river-dominated settings, parallic tide-dominated deposits and tidal mudflat shores. The sister Tafraout Formation on the other hand represented a marginal marine environment, with wave ripples, cross-bedding, the Amphipoda ichnofossil Arenicolites isp. and the calcareous algae Cayeuxia sp., all deposited on diagenetic mudstone. On Taguendouft the Azilal represent the uppermost formation where desiccation cracks are present, overlying marine deposits, indicating a local sea regression. The Parallic depostis host claystone intervals rich in continental organic matter such as wood debris, but scarce fossil fauna, composed by abundant algae, benthic foraminifera, common oncoids, gasteropods and bivalve bioclasts. At the Lowermost Toarcian on the region the carbonate platform was abruptly replaced by siliciclastic deposits and a rise on the ubiquitous occurrence of plant debris, with alternated nearshore-foreshore deposition settings. Is the overlied by storm-dominated deposits, with depauperate fauna and very common occurrence of plant debris, which along the increase of ooid-rich facies suggest the deposition on a warm humid climatic belt. Towards the Middle Toarcian the carbonate producers recovered locally, with the ooid grainstone replaced by wackestone to packstone beds, where heterotrophic faunal bioclasts increase, such as cephalopods, brachiopods, echinoderms, and gastropods, with occasional coral patch reefs. Parallel to this coastal development, increased continental weathering was measured on the layers, as proven by the increase of the coarse-siliciclastic input into the basin, the increased plat debris and the absence of evaporite-rich interval and semi-arid paleosoils. This intervals increased the nutrient levels locally, as proven by the high amount of Phosphorus along all the Atlas Basin. This siliciclastic beds have abundant metamorphic and igneous rock pebbles, implying that the material must be derived from Paleozoic or Proterozoic, the only ones of that nature on Morocco, that on the Atlas are located at the south in the Anti-Atlas, to the west in the Massif Ancien and Jebilet, and to the north in the Meseta Centrale, all locations that where subaerially exposed during the Jurassic. Concretely, the Anti-Atlas shows tectonic uplift, erosion of the overburden processes, that combined with the concentration of the coarse-siliciclastic material in the western part of the central High Atlas (absent in the eastern), suggests that this zone was the source for the Lower Toarcian weathered sediments, allowing to trace the fluvial channels that developed towards the Azilal Formation. The Azilal formation recovers, as seen on worldwide units an increase of weathering due to the Pl/To and T-OAE events, with increase of the siliciclastic sediment supply and increased dissolved material to the oceans. This occurred along an intensification of tropical storm events on the T-OAE, destroying the older carbonate platform organisms locally. This allowed to set the Azilal Formation environments, that range from a series of continental settings with river influence, increased during the T-AOE with more amounts of flora being washed, to nearshore deposits, parallic an subtidal, subject of storm and tropical storm events, all set on a warm humid climate.

In the Middle Toarcian the eastern and north-eastern part of High Atlas of Todrha-Dadès, sedimentation carbonate with bioconstructions (patch-reef), develops with a thickening towards the East and a still thinning towards the West in the direction of the reef of Jbel Akenzoud, where the dew marine fossils of the formation are recovered. The Coralline faunas suffered a significant collapse visible in the locality of Ouguerd Zegzaoune, showing that sedimentation at this time took place in a distensive tectonic context. Then, towards the Late Toarcian-Aalenian series correspond to detrital deposits with carbonate intercalations with neritic fauna. The structural analysis shows that the sedimentation during the upper Toarcian was controlled by a tectonic game, always distensive, causing the tilting of blocks along the transverse fault of NW-SE direction, which leads to the creation of available space with openings always towards E and NE.

Coeval to this units, the western coast Amsittène Formation shows strong continental weathering, as cuts over the CAMP basalts and the triassic continental Red Beds. It recovers subaerial unconformity, with evidence for fluvial erosion, pedogenesis or karstification, with a transition from flood plain to coastal plain deposits. Is interpreted as alluvial fan to flood plain deposits, being on the Agadir sub-basin, more proximal, composed of braided river, flood plain and alluvial fan deposits, while in Tikki evolves vertically from a flood plain to alluvial fan deposits. The local alluvial system was probably related with activity along an ENE-WSW trending fault, parallel to the major Tizi N'Test fault which can be traced from the Argana Valley to the Northeast of the Imouzzer Anticline (Tikki section displays paleocurrents towards the W-SW), and in the case of the Agadir deposits, from older highs, such as the Western Meseta and the Rehamna. The overlying also coeval Ameskhoud Formation records an strong regression on the south of the Essaouira Basin, turning out to be dominated by fluvial deposits, with a few supratidal on the north. The large Variscan belt remains a potential source of sediments for the Toarcian braided river system in the Essaouira Basin.

Connection with lithiotid-coral reefs

At Jebel Toksine in the Dades Valley the Tafraout Formation developed lithiotid-coral reefs. Like in other coeval tethyan units,very likely this section has sections with Mangroves, being the Azilal Formation the dry inland

The Azilal Formation lacks proper marine layers with the common "lithiotids" (an informal group of large, aberrant bivalves), that are know from the Sinemurian to Toarcian of Italy, Spain, Slovenia, Croatia, Montenegro, Albania and also in Morocco. This "Reefs" had a strong zonation, starting with the bivalves Gervilleioperna and Mytiloperna, restricted to intertidal and shallow-subtidal facies. Lithioperna is limited to lagoonal subtidal facies and even in some low-oxygen environments. Finally Lithiotis and Cochlearites are found in subtidal facies, constructing buildups. The Azilal Formation is connected with this type of deposits at least in Jebel Toksine in the Dades Valley, which was deposited in the Tafraout Formation developing local lagoonal-subtidal ecosystems under both arid and humid conditions. The Jebel Toksine layers represent one of the most complete records of this type of ecosystems in morocco, recording multiple generations of lithiotid growth over ~1 km of exposure (composed of the genera Gervilleioperna, Mytiloperna, Lithioperna and Cochlearites), as well a diverse associated fauna, including udotacean algae (Cayeuxia); solitary corals (Archaeosmilia, Zardinophyllidae); phaceloid corals; Periseris (Thamnasterioidea corals); Ampakabastraea (Stylophyllidae); serpulid worm tubes; Arbaciidae echinoids; Scurriopsis Limpets; high-spired gastropods; plant root traces; coalified plant debris & wood logs. The role of the Azilal Formation was likely similar of the Budoš Limestone, with, based on root accumulation, possible ephemeral Mangrove-like environments in the Tafraout Formation and the Azilal representing the nearby dry inland setting.

Tazouda

The Duar of Tazouda layers start overliying bioclastic limestones, indicative of a transgression surface towards continental depostits with both fluvial and volcanic-influenced alluvial sedimentation. The deposit represents channel/floodplain type fluvial system, with channels filled with sand and abundant in plant roots (mostly located in the fine limestone, probably from the channel margins), developed in direction of transit close to E-W. The channels lithology host notable enrichment in material from the Paleozoic basement and from the Mesozoic cover. Interbedding with this layers, volcanic material from sand to pebbles, generally constituting more than half of the detrital components. This basaltic layers host fragments that show clear recrystallization of the carbonates, suggesting that these fragments were still at high temperature during deposition and, therefore, contemporaneous with sedimentation. Lithic elements or isolated crystals found locally do not show signs of prolonged transport, coming likely from relatively close sources, being latter collected and transported by an undeveloped hydrographic network during episodic floods. The location has close marine influences, with intertidal sediments (stromatolites, algal mattes) often highly developed.

The overall local climate was hot with alternating wet and dry periods have generated soils with differentiated limestone profiles (pedogenetic nodules, Caliche), hosting active erosion on soils with sparse vegetation.

Plantae

Floral remains recovered at Tazouda include plant debris with similarities with Conifers (Pinus and Taxaceoids), Cycads and Ferns, this last ones likely developed in punctual wetlands

Paleobotany of the zone has shown that the layers at the Toundoute Continental Series there is not any major wood or plant macrofossil, although there is abundant infra-centimeter plant debris dispersed in the sediments. This debris is composed mostly probably Leaflets of Seed Ferns, and also on lesser quantities, Cycadophytas, most of them with preserved epidermis. Palynological analysis did not deliver any palynomorph, but the Plant debris left some Tracheids. On the debris, however, it was possible to isolate many wood debris, that was revealed to had characters such as Homoxylated structure apparently devoid of Parenchymas, with uniform rays, tracheids with uniseriate punctuation of the genus Abies (Abietoideae) and finally apex spiked type Oculipores vertically oriented, aspects typical from Coniferales, like Abietoideae, Pinaceae or Taxaceae. The Vegetation overall was apparently very dominant by ferns what indicates that may have been concentrated in punctual wetlands. The frequency in the sediments of the fine tuff debris shows the existence of more or less durable water points (spring tuffs) capable of maintaining sufficient humidity in the dry period. A possible correlative flora if found in the same age layers of the Mashabba Formation, North Sinai, Egypt, and is composed by the genera Equisetites (Equisetales), Phlebopteris and Piazopteris branneri (Matoniaceae). Other coeval flora includes the plants recovered on the Budoš Limestone.

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Algae

Genus	Species	Stratigraphic position	Material	Notes	Images
Botryococcus	Botryococcus hraunii Botryococcus sp.	Issouka	Miospores	A Freshwater Green Algae of the family Botryococcaceae. On Issouka, the Toarcian layers have a substantial contribution of freshwater microplankton (sporomorphs and freshwater microplankton, such as Botryococcus). Younger strata shows an increase in marine palynomorphs, indicating a sea transgression happened afterwards.	Extant Specimens

Invertebrates

Ichnofossils

Genus	Species	Location	Material	Type	Made by	Notes	Images
Zoophycos	Zoophycos isp.	Jbel Akenzoud Aghbalou N'Kerdous Taguendouft Tamtetoucht	Dwelling traces	Domichnia & Fodinichnia	Polychaetes (Spionida and Carpitellida) Deposit-feeding Sipuncula	Burrow-like ichnofossils. It has been related to Echiurans, but also from moving and feeding polychaete worms.	Example of Zoophycos fossil
Arenicolites	Arenicolites isp.	Jbel Akenzoud Aghbalou N'Kerdous Taguendouft Tamtetoucht	Dwelling traces	Domichnia	Polychaetes (Spionida and Carpitellida) Suspension-feeding Amphipodan crustaceans Deposit-feeding Sipuncula	Marine, Brackish or Freshwater Unbranched U-shaped burrows having a subvertical orientation, with or without lining and passive fill. Are common on modern coastal environments.
Thalassinoides	Thalassinoides isp.	Aghbalou N'Kerdous Taguendouft Tamtetoucht	Tubular Fodinichnia	Fodinichnia	Thalassinidea Several Crustaceans (Anomura, Decapoda) Annelids (Polychaeta Sipuncula Dipnoi	Burrow-like ichnofossils. Large burrow-systems consisting of smooth-walled, essentially cylindrical components. Common sedimentary features are Thalassinoides trace fossils in the fissile marlstone to claystone intervals	Thalassinoides burrowing structures, with modern related fauna, showing the ecological convergence and the variety of animals that left this Ichnogenus.
Rhizocorallium	Rhizocorallium parallelum	Jbel Akenzoud	Tubular Fodinichnia	Domichnia and/or fodinichnia.	Crustaceans Annelids Fishes	Dwelling and feeding burrow of a suspension-feeder or deposit-feeder, associated usually with shallow waters	Specimens
Chondrites	Chondrites isp.	Aghbalou N'Kerdous Taguendouft Tamtetoucht	Tubular Fodinichnia	Fodinichnia	Annelids (Polychaeta Sipuncula	Burrow-like ichnofossils. Interpreted as the feeding burrow of a sediment-ingesting animal. A more recent study has found that Scoloplos armiger and Heteromastus filiformis, occurring in the German Wadden Sea in the lower parts of tidal flats, make burrows that are homonymous with numerous trace fossils of the ichnogenus.	Illustration of Chondrites bollensis

Brachiopoda

Genus	Species	Stratigraphic position	Material	Notes	Images
Telothyris	Telothyris jauberti Telothyris arnaudi	Jbel Akenzoud	Specimens	A Lobothyrididae Brachiopod. Relatively abundant on seashore deposits. Includes juvenile forms of Telothyris jauberti, present on benthonic deposited strata.
Homoeorhynchia	Homoeorhynchia batalleri Homoeorhynchia meridionalis	Jbel Akenzoud	Specimens	A rhynchonellidae Brachiopod. Relatively abundant on seashore deposits. Homoeorhynchia meridionalis juvenile forms are present.
Stroudithyris	Stroudithyris stephanoides	Jbel Akenzoud 2 km north-east of the village Boumardoul n’Imazighn	Specimens	A Lissajousithyrididae Brachiopod. Mostly benthonic specimens are known.

Vertebrates

Theropoda

Genus	Species	Stratigraphic position	Material	Notes	Images
Theropodipedia	Theropodipedia ichnog. indeterminate	Issil-n-Aït Arbi tracksite	Footprints	Theropod tracks of uncertain affinity
Coelophysidae	Indeterminate	Acforcid, Wazzant.	Dorsal, sacral, caudal vertebrae, chevrons, 3 metatarsals, astragale, calcaneum, phalanges, femur and tibia.	A coelophysid coelophysoid. According to Mickey Mortimer: "Assigned to Coelophysidae based on the apparent fusion between distal tarsal III and metatarsal III". It has been also proposed as a possible tetanuran. That was dismissed by Benson in 2010. Includes at least three different individuals that have been collected in Wazzant: two adults and a newly hatched juvenile. The former foot material resembles the Cretaceous Australian genus Kakuru, that has been proposed as a basal tyrannoraptoran. Mortimer said that "I really don't see much resemblance to Kakuru in the astragalus" and labeled it as a possible dilophosaurid or coelophysoid.
Anchisauripus	Anchisauripus isp.	Aït Blal piste, Demnate tracksite	Footprints	Theropod tracks, type member of the ichnofamily Anchisauripodidae, incertade sedis inside Neotheropoda. Mistaken originally as coelurosaur tracks and tought to come from the underliying Aganane Formation. Includes a pathologic trackway
Eubrontes	Eubrontes isp.	Aït Blal, Demnate tracksite Aït Kelelch, Demnate tracksite	Footprints	Theropod tracks, type member of the ichnofamily Eubrontidae, incertade sedis inside Theropoda. Eubrontes is related to the Genus Dilophosaurus, representing a basal Neotheropods.
Berberosaurus	B. liassicus	Toundoute	Neck vertebra, part of the sacrum, a metacarpal, a femur, and parts of a tibia and both fibulae. Part of another femur has been assigned to the genus as well.	Described originally as a basal representative of the Abelisauroidea, it was recovered as a basal ceratosaur in later studies. It was a medium-sized theropod, measuring 5.1 m (17 ft) long, with a weight of 200 kg (440 lb).	Berberosaurus life restoration and size comparison.
"Tazoudavenator"	No Species Assigned (Invalid)	Toundoute	Femur and several non mentioned remains.	Described as a "Large theropod of uncertain affinities" and as an "enigmatic theropod". To quote Allain: "Two theropods have been found on Toundoute. The first theropod hasn't been described but shows a size larger than any of the know theropods of the Triassic-Early Jurassic know by now, indicating that Toarcian theropods had sizes rivaling that of late Jurassic allosaurs".

Sauropodomorpha

Genus	Species	Stratigraphic position	Material	Notes	Images
Sauropodomorphidia	Sauropodomorphidia ichnog. indeterminate	Issil-n-Aït Arbi tracksite	Footprints	Sauropodomorph tracks of uncertain affinity
Otozoum	Otozoum moodii Otozoum isp.	Issil-n-Aït Arbi tracksite	Footprints	Sauropodomorph tracks, type member of the ichnofamily Otozoidae, incertade sedis inside Sauropodomorpha. Includes a gigantic 84 cm track that represents the largest Otozoum ever described in literature.
Sauropoda	Indeterminate	Acforcid, Wazzant.	Left ilium, a humerus and three vertebrae.	A possible basal sauropod of uncertain affinities. Remains recovered represent a Juvenile
Parabrontopodus	Parabrontopodus isp.	Aguerd tracksite	Footprints	Sauropod tracks, type member of the ichnofamily Parabrontopodidae, incertade sedis inside Sauropodomorpha.
Tazoudasaurus	T. naimi	Toundoute	Partially articulated skeleton and cranial material including complete left mandible with teeth, quadrate, jugal, postorbital, parietal, frontal and exoccipital. Associated remains of a juvenile skeleton.	A gravisaurian sauropod related to Vulcanodon. The most complete sauropod from the Lower Jurassic Found, with adult, sub adult and juvenile specimens.	Representative vertebrae of Tazoudasaurus naimi.
Eusauropoda	Indeterminate	Mizaguène Hill, 3 Km at the Souhtwest of Azilal. East of Azilal, at 1 km at the South of Dar Ou Hammou.	5 dorsal & caudal vertebrae, fragmentary ribs, chevrons and several large badly determinable debris. Various caudal vertebrae and several non studied pieces of large bones.	A eusauropodan sauropod with similarities with Volkheimeria and Klamelisaurus. Was collected on a lagoonal depositional setting.

See also

• Toarcian turnover