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102-508: Levêque called this unit "Marnes chocolat" in the Azilal region, made up of red-brown marls, silts (microsandstones) and conglomerates with centimetric quartz dragees. Locations at Adoumaz , Ghnim and Jbel Taguendouft ( Béni-Mellal Province ) are composed by a succession of reddish-brown tints with terrigenous dominance: sandstone , clays with paleosols and sandstone limestones sometimes dolomitized, with marmorized levels in paleosols towards

204-480: A thin section using a method like the Gazzi-Dickinson Method . This yields the relative percentages of quartz, feldspar, and lithic grains and the amount of clay matrix. The composition of a sandstone can provide important information on the genesis of the sediments when used with a triangular Q uartz, F eldspar, L ithic fragment ( QFL diagrams ). However, geologist have not been able to agree on

306-598: A carbonate-siliclastic regime. By the Middle Toarcian-Aalenian, the Azilal Formation expanded eastward, with isolated carbonates forming in the Amezraï basin, surrounded by terrigenous sediments. This period is marked by the individualization of thein the center of the basin and by a relative tectonic calm in the other coeval sectors. Marine fossils like brachiopods and ammonites help date

408-413: A coastal platform. The formation is mainly made of sandstones, marls, and ooid limestones, different from older layers. Common fossils include bivalves, brachiopods, gastropods, corals, and echinoderms, with plant remains in some sandstones. The rocks formed in environments ranging from supratidal to subtidal, characterized by tropical conditions akin to those observed on Andros, Bahamas . The upper part of

510-688: A deltaic environment with temporary emersions represented by a great variety of settings, including continental river/palustrine-dominated, paralic-tidal deposits, and tidal mudflat shorelines. This terrigenous deposition can be seen from north to south as a lateral transition from a coastal facies to a fluvial facies (at Adoumaz) to a foreshore facies (Ghnim "fining up" type sequences) to a beach facies (Jbel Taguendouft "coarsening up" type sequences). The formation's sedimentary features include raindrop impacts and ripple marks indicating channel/floodplain type fluvial system, with sand-filled channels abundant in plant roots (mostly located in fine limestone, probably from

612-601: A large Mesozoic rift system. Triassic to Cretaceous layers are confined within basins, controlled by extensional rift structures. Sedimentation in these basins varied, with marine shales and limestones in the east and fluvial deposits in the west. Several tectonic events during the Triassic-Jurassic boundary reactivated normal faults, leading to the dominance of marls during the Middle Liassic to Toarcian. "Amezraï" Formation This formation, found in

714-500: A mix of marine and continental conditions, with evidence of emersions. The environment shifted from coastal facies in the north to fluvial facies in the south, and tectonic activity affected sediment deposition. The flow of the fluvial-washed sediments take place in a E-NE direction, being moved to the layers of the Amezräi, Tagoudite & Tafraout Formations and other coeval marine units, as well are found on fluviatile channels inside

816-717: A palaeolatitude between 19°-20°N, around the same latitude as modern Mauritania or Cuba , situated between ancient geological regions like the West Moroccan Arch, the Anti-Atlas and the Sahara craton , developed after a major sea regression, with red clays and conglomerates filling small basins in the Atlas region. Two main stages mark the area's evolution: during the Lower Toarcian, deposition patterns from

918-592: A poorly developed river system during episodic floods. This is recorded specially in the Telouet and Demnate-Wazzant area, but also seen in more detail at Toundoute: the deposits present another channelized floodplain type fluvial system, filled with sand and plant roots/cuticles developed in E-W direction of transit, enriched by both older reworked material and unique interbedded Explosive eruption -type volcanic material (sand to pebbles), generally constituting more than half of

1020-748: A possible dilophosaurid or coelophysoid. Indeterminate Phalanges 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". Gravisauria Indeterminate Pubis and other indeterminate remains A gravisaurian sauropod. Quoted to resemble Tazoudasaurus Eusauropoda Sandstone Sandstone

1122-546: 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

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1224-732: A predominantly fluvial dynamic. On the south-southwest edge of the basin towards west of Azilal (Jbel Til-Jbel Amersiaz basin and part of the M'Goun syncline), Guettioua , Demnate , Telouet , Toundoute & Marrakesh , under the Bajocian limestones ( Tanant Formation ) or directly under the Bajocian?-Bathonian Guettioua Formation , develops a thick a red detrital section in which pelites, sandstones and conglomerates with centimeter-sized quartz balls alternate and breccias (locally called " Wazzant Formation") with Liassic limestone elements, this last ones except near paleofaults, do not appear or have been dissolved. This sector reaches 800 m thickess in

1326-678: A return to warmer conditions. The eastern and northeastern High Atlas saw the development of carbonate sedimentation, with reefs and marine fossils indicating tectonic activity during the Late Toarcian. The central High Atlas region features long diapirs and minibasins formed during early Jurassic rifting, with the Tazoult Ridge being a key example. Diapir movement shaped the surrounding rock layers, while local sedimentation reflects changes in climate, including wetter periods linked to increased erosion. Sharp geological boundaries mark

1428-478: A sandstone goes through as the degree of kinetic processing of the sediments increases. Dott's (1964) sandstone classification scheme is one of many such schemes used by geologists for classifying sandstones. Dott's scheme is a modification of Gilbert's classification of silicate sandstones, and it incorporates R.L. Folk's dual textural and compositional maturity concepts into one classification system. The philosophy behind combining Gilbert's and R. L. Folk's schemes

1530-462: A set of boundaries separating regions of the QFL triangle. Visual aids are diagrams that allow geologists to interpret different characteristics of a sandstone. For example, a QFL chart can be marked with a provenance model that shows the likely tectonic origin of sandstones with various compositions of framework grains. Likewise, the stage of textural maturity chart illustrates the different stages that

1632-619: A shrinking of the local carbonate platform width. The base of the East Azilal Formation is not clear, there is a gradual passage between the underlying limestones of the Aganane Formation and the red pelites of the Azilal Formation. The upper limit is marked by a progressive transition to Bin-el-Ouidane limestones with the limit fixed at the base of the first massive limestones, generally “birds eyes”. In

1734-436: A subordinate form. Biogenic pelmicrites and oomicrites/wackestones are rare facies. In addition to individual Ostracods , Mussel shells, foraminifera and Scytonemataceae Cyanobacteria ( Ortonella spp. ), Bioturbation is present. Dolomites , whose components are either completely recognizable or only barely identifiable, depending on the degree of dolomitization. Sandstone / Conglomerate/ Marl : The sandstones of

1836-635: A succession rain tundra to wet forest environments, as proven by samples from coeval layers in the External Rif Chain . There is also a local record of a Middle Toarcian Cold Snap at Jbel Akenzoud , 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

1938-488: A succession rain tundra to wet forest environments, as proven by samples from coeval layers in the External Rif Chain . The Continental/Tidal Flat Azilal Formation , within this group, was deposited in coastal environments influenced by rivers, tidal flats, and paralic settings, rwith eworked material and in Toundoute unique interbedded Explosive eruption -type volcanic material, generally constituting more than half of

2040-445: A twofold classification: Cement is what binds the siliciclastic framework grains together. Cement is a secondary mineral that forms after deposition and during burial of the sandstone. These cementing materials may be either silicate minerals or non-silicate minerals, such as calcite. Sandstone that becomes depleted of its cement binder through weathering gradually becomes friable and unstable. This process can be somewhat reversed by

2142-434: A weight of 200 kg (440 lb). Coelophysidae Indeterminate Two adults and one recently hatched juvenile. At least the posterior half of the skeleton is present: caudal, sacral, dorsal vertebrae, pelvis and both hind legs 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

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2244-502: Is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains, cemented together by another mineral. Sandstones comprise about 20–25% of all sedimentary rocks . Most sandstone is composed of quartz or feldspar , because they are the most resistant minerals to the weathering processes at the Earth's surface. Like uncemented sand , sandstone may be imparted any color by impurities within

2346-837: Is a distinction that can be recognized in the field . In turn, the distinction between an orthoquartzite and a metaquartzite is the onset of recrystallization of existing grains. The dividing line may be placed at the point where strained quartz grains begin to be replaced by new, unstrained, small quartz grains, producing a mortar texture that can be identified in thin sections under a polarizing microscope. With increasing grade of metamorphism, further recrystallization produces foam texture , characterized by polygonal grains meeting at triple junctions, and then porphyroblastic texture , characterized by coarse, irregular grains, including some larger grains ( porphyroblasts .) Sandstone has been used since prehistoric times for construction, decorative art works and tools. It has been widely employed around

2448-482: Is an oblique bedding, of metric dimensions, drawing on the surface mega-ripples of 3 to 5 m in wavelength. The last major section represents a supratidal deposit, as shown by the presence of coarse sandstone gradually changing to red Marls with "fluer" structures and locally to paleosols. This section in Adoumaz has abundance of Paleozoic quartz grains, that are found organized in decametric channeling lenses evoking

2550-459: Is explained by the alternation of permeable and impermeable levels. Springs spring up at the top of this unit, under limestones (Tanant or Bin-el-Ouidane Formations), as in Bernat. The numerous wells dug on the northern edge of Guettioua testify to this unit aquifer qualities, with water accumulated in the sandstone-conglomeratic levels interstratified in the pelites. The Azilal Formation, located on

2652-523: Is likely formed during eogenesis. Deeper burial is accompanied by mesogenesis , during which most of the compaction and lithification takes place. Compaction takes place as the sand comes under increasing pressure from overlying sediments. Sediment grains move into more compact arrangements, ductile grains (such as mica grains) are deformed, and pore space is reduced. In addition to this physical compaction, chemical compaction may take place via pressure solution . Points of contact between grains are under

2754-431: Is redeposited in the unstrained pore spaces. Mechanical compaction takes place primarily at depths less than 1,000 meters (3,300 ft). Chemical compaction continues to depths of 2,000 meters (6,600 ft), and most cementation takes place at depths of 2,000–5,000 meters (6,600–16,400 ft). Unroofing of buried sandstone is accompanied by telogenesis , the third and final stage of diagenesis. As erosion reduces

2856-443: Is that it is better able to "portray the continuous nature of textural variation from mudstone to arenite and from stable to unstable grain composition". Dott's classification scheme is based on the mineralogy of framework grains, and on the type of matrix present in between the framework grains. In this specific classification scheme, Dott has set the boundary between arenite and wackes at 15% matrix. In addition, Dott also breaks up

2958-791: 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. The Tafraout Group was formed on the Moroccan Carbonate Platform during a sea-level rise in the Early Toarcian, linked to the Toarcian Oceanic Anoxic Event , at

3060-606: The Azilal Formation (continental to subtidal, including its synonyms the "Wazzant Formation" and the "Continental Series of Toundoute"); the " Amezraï" Formation (intertidal environment); the Tafraout Formation (deposited in a subtidal to inner platform environment) & the Tagoudite Formation (including the "Tamadout Formation", shallow subtidal to open pelagic). They are connected with

3162-678: The Global Heritage Stone Resource . In some regions of Argentina, the orthoquartzite-stoned facade is one of the main features of the Mar del Plata style bungalows. Tafraout Formation The Tafraout Group (Also "Tafraoute Group" or Zaouiat Ahançal Group ) is a geological group of formations of Toarcian - Aalenian ( Lower Jurassic - Middle Jurassic ) age in the Azilal , Béni-Mellal , Imilchil , Zaouiat Ahansal , Ouarzazate , Tinerhir and Errachidia areas of

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3264-555: The Tafraout Formation , with the transgressive "S10", whose end marks the major post Middle Toarcian transgressive event, composed of bioclaetic or oncolithic limestones, poorly developed low-marine-level prisms & marly limestones with oblique stratifications, while oolitic limestones mark smaller transgressive events, and then the major one towards the Bajocian with the Aït Abdi/Bin el Ouidane Formation, flooding again all

3366-764: The Talmest-Tazolt Ridge to the North and the North-Atlasic accident to the South. This terrestrial lithology is mostly found in the small basins in tearing in the Atlas of Telouet, Toundoute, Afourer and Azilal, having the Demnat Accident as the major structural element in this last sector. While at this W areas it becames fully terrestrial/intertidal, at other areas like Beni Mellal , Dadès Gorges or Zaouiat Ahansal marine influences are seen in

3468-498: The percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs . Quartz-bearing sandstone can be changed into quartzite through metamorphism , usually related to tectonic compression within orogenic belts . Sandstones are clastic in origin (as opposed to either organic , like chalk and coal , or chemical , like gypsum and jasper ). The silicate sand grains from which they form are

3570-544: The Amezraï minibasin and linked to the Tazoult Ridge, dates to the Earliest Toarcian and is identified by brachiopod fossils. It includes sandstones, marls, and biodetrital or oolitic limestones, with layers varying from centimeters to up to 6 meters thick. The lower part consists of conglomerates, sandstones, and clays, transitioning to limestones and marls at the top. Ripple structures and cross-bedding are common in sandstone layers, while reworked horizons appear in

3672-533: The Anti-Atlas shows processes of tectonic uplift, overburden erosion, which, combined with the concentration of coarse siliciclastic material in the western part of the central High Atlas (absent in the east), suggest that this area was the source of the altered Lower Toarcian sediments, allowing the tracing of the fluvial channels that developed towards the Azilal Formation. The surrounding highlands probably hosted dry cool (10.6 °C) to humid climate (12.30 °C), with

3774-571: The Azilal Formation are composed of quartz clay, some Feldspar and Glauconite . Pyrite , Malachite , as well as bone and plant remains are found. In the microconglomerate gullies there are also clasts (mainly quartz, quartzite, Granite , Basalt , clay, sandstone) from the Paleozoic and to a lesser extent from the Triassic and Jurassic. The Azilal Formation constitutes a depressed zone, often intensely cultivated, rich in springs and wells. This

3876-633: The Azilal Province. Some of them are recovered in a " Bone bed " and others are associated with abundant plant remains. Marine, brackish or freshwater bony fish of the family Leptolepidae . Recovered from the Tagoudite Formation, represents a genus of cosmopolitan fish, common in the Toarcian Mediterranean area. Most specimens appear to come from lagoonal facies. Indeterminate Marine or brackish bony fish of

3978-587: The Azilal Province. Some of them are recovered in a " Bone bed " and others are associated with abundant plant remains. Small Tridactyl Footprints were reported from the E of Azilal in the upper layers of the Formation. Berberosaurus B. liassicus 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

4080-537: The Carbonate production. The Tafraout Platform deepened over time, signaling a shift to transgressive conditions even with the expansion of W continental facies. On the Amezraï Formation basin the fauna is composed by brachiopods such as Soaresirhynchia bouchardi , S. babtisrensis and Pseudogibbirhynchia jurensis that corroborate the Earliest Toarcian age for it and adjacent layers. Meanwhile,

4182-622: The E. At areas like Talmest-Tazoult the expansion of the Azilal intercalates it´s shoreline with returning widespread carbonate sedimentation, were an open carbonate platform, Tafraout Platform, sees it´s surface being moved towards the E, returning latter to fully marine conditions. The Azilal Formation, part of the Tafraout Group in the Western High Atlas, was deposited in a coastal environment with continental influence. It consists of terrigenous-dominated deposits, reflecting

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4284-650: The High Atlas of Morocco . The Group represents the remnants of a local massive Siliciclastic-Carbonate platform ("Tafraout Platform"), best assigned to succession W-E of alluvial environment occasionally interrupted by shallow marine incursions (tidal flat setting) and inner platform to open marine settings, and marks a dramatic decrease of the carbonate productivity under increasing terrigenous sedimentation. Fossils include large reef biotas with richness in "lithiotid" bivalves and coral mounts ("Patch reef", Tafraout Formation ), but also by remains of vertebrates such as

4386-680: The Lower Toarcian, a shift to siliciclastic deposits occurred, marked by storm events and increased plant debris, indicating a warm, humid climate. Some areas, especially near the coast, resembled modern Sabkha (like those in the Persian Gulf ). The Tafraout Formation , meanwhile, represented marginal marine environments with diverse marine fauna, including coral reefs and "lithiotid" ( Plicatostylidae aberrant reef-forming) bivalves. The Toarcian Oceanic Anoxic Event (T-OAE) intensified Tropical storms , destroying older carbonate platforms and increasing siliciclastic deposits, which contributed to

4488-689: The Lower Toarcian, proven by sections such as "Tarhia n’Dadès", where the Pliensbachian Choucht Formation marginal marine layers are overlain by one meter of red silt/bioclastic limestone alternations, that start a local paralic to continental environments, assigned to the Domerian Aganane Formation . Over this unit the limit with the Azilal formation is marked with a karstified subaerial exposure surface, that wears also great abundance of plant material, what overall implicates prograding terrestrial facies and

4590-736: The Middle Toarcian onwards, here recovered under the "Tidrite section", made of fine terrigenous deposits interbedded with dolomitized limestone. The layers previously called " Aguerd-n'Tazoult formation " represent the most recent marginal marine layers in the Amezraï minibasin, dating from the Upper Toarcian-Aalenian periods and mark the E expansion of the Azilal Formation. It begins with layers that have many conglomerate lenses and ends with coral patch reefs. Sandstones, oolitic, and biodetritic limestones are also found throughout. Red and green marls appear in several layers. In

4692-508: The Moroccan Carbonate Platform at a palaeolatitude of 19°-20°N, developed during a major drowning episode linked to the Toarcian Anoxic event. It is bounded by the West Moroccan Arch, Anti-Atlas, and Sahara craton. Initially, local laguno-marine facies were overlain by terrigenous deposits post-Toarcian regression, filling small basins in the Atlas of Afourer and Azilal. In Demnate and nearby areas, conditions became terrestrial, while to

4794-637: The N of Wazzant or Ait Bou Oulli . The western upper limit is marked by greenish clayey levels are interspersed between the red pelites, then limestone banks, gradually changuing into the Bajocian Tanant Formation , as can be seen at Tizi-n-Takiout on Aït-Blal. Evidence of volcanism contemporaneous with the deposition of the Azilal Formation is almost nonexistent, and where volcanic rocks have been assigned, they have been repositioned as either younger or CAMP. The only possible record are explosive volcanic eruption beds found associated with

4896-536: The S the Dolomites of Jbel n' Ourkar member is recovered, made of yellow dolomites with intercalated multicolor marls. In the Talmest-Tazoult area, the formation is made of yellow limestones and marls, hybrid sandstones, micritic limestones, having reef ledges in the upper part and red sandstones and marls in the lower part. Here the formation is part of a large +200 m thick yellowish limestone bar, overliying

4998-553: The Tafraout Group, the fossil record of units like the Azilal Formation is very restrictive compared to the marine coeval/underliying units like the Amezraï or Tafraout Formations. In the Dadés area Coral patch reefs rarely occur in the middle of the unit with associated echinodems ( Sea urchin spines, Crinoid fragments) lamellibranchs, gastropods, solitary corals and algae. Plant remains are very abundant in places such as

5100-516: The Wazzant subasin, being very reduced to the south of it in Aït-Toutline or Aït-Iouaridène , recovering a variation of the sedimentary process formed by a complex sedimentary unit, terrigenously dominated, composed by the abundance of conglomeratic channels with quartz dragees and Paleozoic basement elements, sandstones organized in bars channeled lenticulars and red clays, the whole part of

5202-491: The application of tetraethyl orthosilicate (Si(OC 2 H 5 ) 4 ) which will deposit amorphous silicon dioxide between the sand grains. The reaction is as follows. Pore space includes the open spaces within a rock or a soil. The pore space in a rock has a direct relationship to the porosity and permeability of the rock. The porosity and permeability are directly influenced by the way the sand grains are packed together. Sandstones are typically classified by point-counting

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5304-1165: The bivalve pavements. The platform patch reefs in the Tafraout area are notable for their biodiversity, with some reaching heights of up to 40 m and lengths of up to 80 m, representing massive biostromes with a varied associated fossil assemblage, including bivalves, gastropods, echinoderm fragments, solitary corals, and bryozoans, found among the coral patchs. Massive reef pinnacles are recovered at Anergui and northern flank of Tassent, while rarer ones are know from Bou Zemou. Multiple Gasteropodan faunas are know, specially associated with coral patch reefs, but lack proper studies. Multiple echinoderm remains, including Crinoid articulated and fragmentary specimens and indeterminate echinoid fragments, are know from several localities, usually associated with large coral bioherms or sea trangressions. Several scales & teeth of fishes ( Lepidotes ?) are know from several locations, coming from freshwater/lagoonal layers. Indeterminate dinosaurian & other vertebrates are know from Mizaguène Hill, Taouja Ougourane, Aït Ouaridène, Oued Rzef & Jbel Remuai in

5406-683: 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. 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

5508-587: The channel margins), along with evidence of ephemeral Palustrine ( Sabkhas , Chotts ) episodes in the form of carbonate bodies ( Caliche or Calcrete levels), intercalated with conglomerate under an arid environment, as marks the development of gypsum. The high abundance of plant remains, either as fossil wood, cuticles, charcoal or Rhizoliths , reveals the presence of vegetated soils in the vicinity. Lithic elements or isolated crystals found locally show no evidence of prolonged transport, probably from relatively nearby Springs , being these collected and transported by

5610-546: The closure of salt walls during diapir growth, and ancient environments here resembled modern shallow waters like the Red Sea . Charcoal remnants suggest coastal forests or mangroves existed during wetter times. the Pliensbachian-Toarcian interval. Tasmanites Cysts A member of Prasinophyceae . The presence of this genus indicates fresh or brackish water inputs in the depositional environment In

5712-473: The common minerals most resistant to weathering processes at the Earth's surface, as seen in the Goldich dissolution series . Framework grains can be classified into several different categories based on their mineral composition: Matrix is very fine material, which is present within interstitial pore space between the framework grains. The nature of the matrix within the interstitial pore space results in

5814-456: The depositional environment, older sand is buried by younger sediments, and it undergoes diagenesis . This mostly consists of compaction and lithification of the sand. Early stages of diagenesis, described as eogenesis , take place at shallow depths (a few tens of meters) and are characterized by bioturbation and mineralogical changes in the sands, with only slight compaction. The red hematite that gives red bed sandstones their color

5916-407: The depth of burial, renewed exposure to meteoric water produces additional changes to the sandstone, such as dissolution of some of the cement to produce secondary porosity . Framework grains are sand-sized (0.0625-to-2-millimeter (0.00246 to 0.07874 in) diameter) detrital fragments that make up the bulk of a sandstone. Most framework grains are composed of quartz or feldspar , which are

6018-404: The detrital components, showing clear carbonate recrystallization, suggesting that these fragments were still at high temperature during deposition and, therefore, contemporaneous with the sedimentation, probably as a result of early activity in the local South-Atlasic Fault. Fauna, including rare brachiopods and bivalves, alongside sedimentary features like ripple marks and rain imprints, indicate

6120-422: The detrital components, showing clear carbonate recrystallization, suggesting that these fragments were still at high temperature during deposition and, therefore, contemporaneous with the sedimentation, probably as a result of early activity in the local South-Atlasic Fault. The formation also shows evidence of erosion from nearby highlands,as indicates abundant pebbles of metamorphic and igneous rocks, implying that

6222-446: The different types of framework grains that can be present in a sandstone into three major categories: quartz, feldspar, and lithic grains. When sandstone is subjected to the great heat and pressure associated with regional metamorphism , the individual quartz grains recrystallize, along with the former cementing material, to form the metamorphic rock called quartzite . Most or all of the original texture and sedimentary structures of

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6324-542: The earlier Pliensbachian continued, followed by terrigenous materials filling the basins and stopping temporally the carbonate production. It evolved along several depocenters and associated accidents, the southern edge of the Tilougguit Syncline in the north to the axis of the Aït Bouguemmez Basin in the south, showed that the depocenter zone corresponded to the disposal area located between

6426-422: The early Late Toarcian. The fossil record of the Azilal Formation is very restrictive compared to the marine coeval/underliying units, like the Tafraout Formation . In the Dadés area Coral patch reefs rarely occur in the middle of the unit with associated echinodems ( Sea urchin spines, Crinoid fragments) lamellibranchs, gastropods, solitary corals and algae. Plant remains are very abundant in places such as

6528-427: The east at Beni-Mellal, the sea regression occurred later. The Amezraï minbasin evolved as an isolated carbonate environment. The formation expanded eastward during the Middle Toarcian-Aalenian, marked by tectonic calm and sedimentation of terrigenous and carbonate layers. The Azilal Formation spans post-Polymorphum levels, with notable sea regression and specific faunal assemblages confirming its Toarcian age, Meanwhile

6630-519: The facies is organized in metric sequences of filling and alluvial channels. In addition, exceptionally, at the Wazzant area it rests in this place directly on massive dolomites, having eroded the marno-limestones of the Pliensbachian, with transitional layers. A transition between marine and continental deposits, is seen through carbonate palustrine levels and horizons of caliche , being continental layers superimposed in stratigraphic continuity on

6732-539: The family Leptolepidae. The vegetation in the Toundoute area is compared to that of the Isle of Pines . Paleosols in these regions show many plant roots ( Rhizoliths ) and heavily disturbed layers. Plant remains include coal, leaves, woody roots, rhizoliths, fossil wood, and other plant debris. In Toundoute, small plant fragments, mostly fern leaflets and some cycad leaves, were found, with wood debris resembling conifers like Pinaceae or Taxaceae. Ferns seem to have dominated

6834-524: The formation of the Tafrout environment. Additionally, after the T-OAE, ecosystems in areas like Jebel Toksine began to recover with new carbonate activity and diverse marine life, including bivalves and other reef organisms. The aftermath of the T-OAE is visible in the lower Azilal Formation, showing a slow recovery of marine environments. There is also evidence of a Middle Toarcian cold snap, followed by

6936-465: The formation shows sediments filling an old Pliensbachian basin, moving from deeper marine conditions to a supratidal coastal plain. Fossils and sediment features suggest a challenging environment, with alternating sandstone and marl layers indicating changes in water depth and sedimentation patterns. Tagoudite Formation The Tagoudite Formation marks a major shift in Liassic sedimentation, replacing

7038-433: The genus Girvanella . Finally, there are intercalations of fine, often laminated sandstone which mark the inondation facies of the channels during flood periods, being composed solely of feldspars plagioclase and to a lesser extent of orthoclase , as well as small ferruginous grains or fine silts of quartz . Due to the strong Dolomitization affecting the strata of this formation it is difficult to describe in detail

7140-433: The greatest strain, and the strained mineral is more soluble than the rest of the grain. As a result, the contact points are dissolved away, allowing the grains to come into closer contact. Lithification follows closely on compaction, as increased temperatures at depth hasten deposition of cement that binds the grains together. Pressure solution contributes to cementing, as the mineral dissolved from strained contact points

7242-442: The hardness of individual grains, uniformity of grain size and friability of their structure, some types of sandstone are excellent materials from which to make grindstones , for sharpening blades and other implements. Non-friable sandstone can be used to make grindstones for grinding grain, e.g., gritstone . A type of pure quartz sandstone, orthoquartzite, with more of 90–95 percent of quartz, has been proposed for nomination to

7344-625: The layers where was discovered. Planammatoceras Isolated Shell An Ammonite of the family Hammatoceratidae . Indicator of a Middle Aalenian age for the uppermost layers, as is found also on the Middle Atlas. As well evidence of greater marine influx in the easternmost outcrops. Several scales & teeth of fishes ( Lepidotes ?) are know from several locations, coming from freshwater/lagoonal layers. Indeterminate dinosaurian & other vertebrates are known from Mizaguène Hill, Taouja Ougourane, Aït Ouaridène, Oued Rzef & Jbel Remuai in

7446-640: The limestone. The formation reflects a subtidal to supratidal environment, with some layers suggesting lagoonal conditions and reduced carbonate content compared to older formations. Local tectonic activity, mainly due to seismic events in the Tethyan region, influenced the formation, causing erosion of older Paleozoic layers. Azilal Formation Tafraout Formation The Tafraout Formation consists of oolitic and biodetrital limestones with cross-stratifications, found in channels and bars, alongside greenish marls and micro-conglomerates. These layers were deposited on

7548-426: The lower sequences, with fine conglomerate layers and plant remains indicate a proximal delivery area and the peak of the regression, with many microlagoons that formed between the large coral patch reefs are documented by micrite and partially leached micrite. The Tafraout Group covers most of the W High Atlas, surrounded by highlands that probably hosted dry cool (10.6 °C) to humid climate (12.30 °C), with

7650-515: The marine carbonates of the Aganane or older Imi-n-Ifri Formation . The Wazzant area river system was driven by several minor freshwater currents, likely temporal and related to the rainy seasons. It has a notorious proximal character compared to the other sections of the Azilal formation. In the Dadés area the formation is present asynchronously, seen in the W in the Earliest Toarcian, yet in some areas like Boumardoul n’Imazighn doesn´t reach until

7752-691: The material must have been derived from the Paleozoic or Proterozoic , implying a hinterland that is frequently emerged and subject to erosion and the effects of diagenesis, locally either to the south in the Anti-Atlas , to the west in the Ancient Massif and the Jebilet , and to the north in the Central Meseta , all places that were subaerially exposed during the Jurassic. Specifically,

7854-429: The microfacies types, yet the following types of microfacies were distinguished: The first include laminated algal boundstones, with broad areal are characterized by yellow dolomitized Stromatolites . Characteristic of this type of microfacies are cavity channels, which are often arranged parallel to the layering. The presence of peloids is an important facies indicator for the supratidal zone, being transported into

7956-491: The minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Because sandstone beds can form highly visible cliffs and other topographic features, certain colors of sandstone have become strongly identified with certain regions, such as the red rock deserts of Arches National Park and other areas of the American Southwest . Rock formations composed of sandstone usually allow

8058-678: The mountain range. The after-effects of the Toarcian Oceanic Anoxic Event are also very present in the marginal marine strata of the Tafraout Group, with the Toksine Section recording a dramatic collapse on the scale of the Tethys of the neritic carbonate system. The Central High Atlas of Morocco is part of a mountain belt formed by the inversion of a rift from the Triassic -Jurassic periods, due to Cenozoic tectonic activity. The region's structure comes from four main tectonic phases:

8160-493: The much lower temperatures and pressures associated with diagenesis of sedimentary rock, but diagenesis has cemented the rock so thoroughly that microscopic examination is necessary to distinguish it from metamorphic quartzite. The term orthoquartzite is used to distinguish such sedimentary rock from metaquartzite produced by metamorphism. By extension, the term orthoquartzite has occasionally been more generally applied to any quartz-cemented quartz arenite . Orthoquartzite (in

8262-464: The narrow sense) is often 99% SiO 2 with only very minor amounts of iron oxide and trace resistant minerals such as zircon , rutile and magnetite . Although few fossils are normally present, the original texture and sedimentary structures are preserved. The typical distinction between a true orthoquartzite and an ordinary quartz sandstone is that an orthoquartzite is so highly cemented that it will fracture across grains, not around them. This

8364-507: The north of Jbel Akenzoud and partly impregnated and/or carbonized by malachite . Gastropods have been discovered in several places, but none of the specimens have been studied nor identified. Beds with large accumulations of unidentified Ostracod valves on an endemic thin level of green marl are found at the Beni-Mellal area (Adoumaz & Col de Ghnim outcrops). The tubes of serpulid worms are known from Jbel Toksine, in relation to

8466-443: The north of Jbel Akenzoud and partly impregnated and/or carbonized by malachite . Gastropods have been discovered in several places, but none of the specimens have been studied nor identified. Beds with large accumulations of unidentified Ostracod valves on an endemic thin level of green marl are found at the Beni-Mellal area (Adoumaz & Col de Ghnim outcrops). "Dwarf black bivalves (Lucinidae?)" in great abundance where reported from

8568-466: The northern region of Ghnim and Adoumaz. The lowermost sections show a transition from sandstone limestone and/or sandstone to clay, with a thin level of green marls locally rich in ostracods. This initial layers are followed by a subtidal term, represented by an oolitic limestone, with fine lamellibranch bioclasts and variable percentages of quartz , that host also small sections of sandstone with calcareous cement and rare oolites, representing this last one

8670-490: The offshore Ait Athmane Formation and the deeper shelf deposits of the Agoudim 1 Formation . Overall, this group represents a mixed carbonate-siliciclastic system of several hundred meters thick, dominated by deposits of shallow marine platforms linked to a nearby hinterland dominated by conglomerates. The strata of the group extend towards the central High Atlas, covering different anticlines and topographic features along

8772-991: The outcrops at Toundoute, maybe associated to premature activity of the mobile area along the line of the South-Atlasic Fault with Trachyandesitic materials from a explosive source, like in the older Mouluya outcrops like the Tizi-nGhachou sector. The lithology of the Azilal Formation recovers 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, with faunal content very poor and mostly dominated by microbial facies. This unit brings together sandstones, sometimes coarse or conglomeratics, especially red silts and some irregularly bedding carbonate horizons (lacustrine limestones?) as well as rarer coal beds. At

8874-524: The own rocks of this unit. The Azilal Formation also saw high plant activity, with remains such as wood, charcoal, and rhizoliths, indicating nearby vegetated soils. Fluvial systems transported sediment from Paleozoic and Triassic sources, with volcanic material also present, suggesting active volcanic processes during deposition. The warm, alternating wet and dry climate led to the formation of soils with calcareous nodules and gypsum in arid zones, particularly in areas like Toundoute and Telouet. During

8976-531: The pre-rift phase tied to the formation of Pangaea , the syn-rift phase during the Late Permian to Late Triassic, influenced by the opening of the Atlantic Ocean and Tethys Ocean , and the post-rift phase, where Jurassic-Cretaceous carbonate platforms formed. The High Atlas has thrust and oblique-slip faults from W-E to NE-SW. It is an intracontinental mountain range resulting from the uplift of

9078-533: The presence of Aalenian ( Bradfordernsis-Murchinsonae ) Branchiopods in the Azilal Formation coeval with Ammonites of the same age at the Ikerzi Area confirms the marine delimitation in the last stages of deposition. In the Azilal system, the "Tafraout Platform" saw a deepening towards the uppermost layers, teasing the transition to the Bin El Ouidane transgressive Carbonate Platform facies, while

9180-438: The presence of Aalenian (Bradfordernsis-Murchinsonae) Branchiopods in the frontal marine member ("Aguerd-nˈTazoult") coeval with Ammonites of the same age in the easternmost Azilal formation at the Ikerzi Area confirms the marine delimitation on a carbonate platform in the last stages of deposition. This sequence is dominated by supratidal to intertidal layers, with abundant bird´s eyes and mudcracks that become more marine towards

9282-638: The product of physical and chemical weathering of bedrock. Weathering and erosion are most rapid in areas of high relief, such as volcanic arcs , areas of continental rifting , and orogenic belts . Eroded sand is transported by rivers or by the wind from its source areas to depositional environments where tectonics has created accommodation space for sediments to accumulate. Forearc basins tend to accumulate sand rich in lithic grains and plagioclase . Intracontinental basins and grabens along continental margins are also common environments for deposition of sand. As sediments continue to accumulate in

9384-825: The rest is made up of fragments of rocks, often quartzose and schistosose with presence of vitreous rocks and spongy Glauconite ; calcite cements the elements and fills vacuoles. The absence of heavy minerals and Plagioclase clearly indicate that these sandstones come from the dismantling of a non-granite base. Other proximal areas show Sieve - Conglomerate lenticular channels of ~5 m (16 ft) thickness (≤ 5 m (16 ft)), composed of several materials, such as volcanic products in Toundoute (blocks of sands composed of Feldspars , black ferruginous grains, siliceous green fragments of veins , microgeods, hummocky concretions), limestone debris with traces of roots and cracks, where in some parts traces of fine, dark brushy algal filaments are still visible, similar to blue-green algae of

9486-417: The sandstone are erased by the metamorphism. The grains are so tightly interlocked that when the rock is broken, it fractures through the grains to form an irregular or conchoidal fracture. Geologists had recognized by 1941 that some rocks show the macroscopic characteristics of quartzite, even though they have not undergone metamorphism at high pressure and temperature. These rocks have been subject only to

9588-572: The sauropod Tazoudasaurus and the basal ceratosaur Berberosaurus , along with several undescribed genera. While there have been attributions of its lowermost layers to the Latest Pliensbachian, the current oldest properly measured are part of the Earliest Toarcian regression ("MRST10"), part of the Lower-Middle Palymorphum biozone. This group is composed of the following units, which extend from west to east:

9690-400: The sector. The layers at Azilal evolved along the central high Altas Toarcian-Aalenian Siliclastic-Carbonate Platform, and consist 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 unit represents a major sea regression measured in the central High Atlas, specially after

9792-536: The sediment layers and confirm the transition from marine to expansive E terrestrial environments during the Middle Toarcian. The deposition starts with a marked break of the Carbonate production and a major regression in the Lowermost Toarcian, then oscilated Transgresive/Regresive cycles in the Laevisoni-Bifrons substages, followed finally by a post Bifrons major regression and full return to

9894-468: The tidal flats by periodic storms and then covered in turn by Microbial mats . The oosparites/ Wackestones along dolomitic grainstones occur rarely, usually only as sparsely massive, gray to yellow layers, which are often obliquely stratified. This layers have diverse but scarce biocomponents, some of which form ooid cores and consist of Foraminifera , Echinoderms , Lamellibranch , Gastropods and Algae . Intraclasts are usually rounded. Peloids occur in

9996-417: The unit at it´s type section. Rhizocorallium Tubular Fodinichnia Domichnia and/or fodinichnia. Dwelling and feeding burrow of a suspension-feeder or deposit-feeder, associated usually with shallow waters Stroudithyris Isolated Shells A Brackish Lissajousithyrididae Brachiopod . Mostly benthonic specimens are known. The presence of this species indicates an upper Toarcian-Aalenian age for

10098-498: The vegetation, likely in wetlands, followed by cycads and conifers. Similar plants have been found in Egypt's Mashabba Formation . At Jebel Toksine, woody plant debris, including charcoal, suggests vegetation in a humid, marginal marine environment. Jebel Azourki has layers of shales with coal streaks and plant fragments, possibly representing a marsh in a lagoon area. Phytoclasts, spores, pollen and Tasmanites algae indicate that

10200-579: The west it rests conformably and with progressive passage either on the Aït-Bazzi Formation , or on its lateral equivalent the Aganane, as can be seen at Ait Blal and Tacht where limestone banks are gradually interspersed in the red pelites. In other places is clearly discordant on the sediments of the Sinemurian-Pliensbachian which can be found barely blunted blocks in its conglomeratic levels, as can be seen in places like

10302-593: The west this unit consists of conglomerates, sandstones and red pelites. The sandstone and conglomeratic levels are lenticular with frequent oblique stratifications. While it can be complex to differenciate from the Guettioua Formation or the Oukaïmeden Sandstone , conglomerates with multicolored quartz balls of centimeter diameter are the major unique trait of the Azilal Formation. This sequences record predominance of quartz grains (> 50),

10404-626: The world in constructing temples, churches, homes and other buildings, and in civil engineering . Although its resistance to weathering varies, sandstone is easy to work. That makes it a common building and paving material, including in asphalt concrete . However, some types that have been used in the past, such as the Collyhurst sandstone used in North West England , have had poor long-term weather resistance, necessitating repair and replacement in older buildings. Because of

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