Mohammed Et-Touhami

Mohamed I University | UMP · Department of Geology

The Bigoudine Fm represents one of the most widespread facies of the Moroccan Triassic on land and on the shelf with close counterparts on the conjugate Scotian shelf and onshore Atlantic Canada. We describe a magnetic polarity stratigraphy for the Bigoudine based on >300 sampling sites spanning >990 m of composite section comprised of 10 outcrop s...

Life Versus the Volcanoes Correlating a specific triggering event, such as an asteroid impact or massive volcanism, to mass extinction events is clouded by the difficulty in precisely timing their occurrence in the geologic record. Based on rock samples collected in North America and Morocco, Blackburn et al. (p. 941 , published online 21 March) ac...

We are very pleased with the attention, long overdue, that the Triassic–Jurassic boundary and associated events, such as the CAMP, are receiving. This can only lead to greater specificity of hypotheses and greater understanding in the long run, and it is worth emphasizing some broad areas of agreement. Marzoli et al. (2008-this volume) points out t...

Early Mesozoic tholeiitic flood basalts of the Central Atlantic Magmatic Province (CAMP) are interbedded throughout much of their extent with cyclical lacustrine strata, allowing Milankovitch calibration of the duration of the extrusive episode. This cyclostratigraphy extends from the Newark basin of the northeastern US, where it was first worked o...

Three major paleoenvironmental changes have been recognized during the late Miocene to Early Pliocene in the Melilla Basin (Northeastern Morocco) and compared with the regional events that affected the Mediterranean hydrology during this crucial period. The first change was the definitive conversion of the restricted marine conditions that prevaile...

The end-Triassic extinction (ETE) on land was synchronous with the initial lavas of the Central Atlantic Magmatic Province (CAMP) and occurred just after the brief 26 thousand year (kyr) reverse geomagnetic polarity Chron E23r that can be used for global correlation. Lava-by-lava paleomagnetic secular variation data, previously reported from Morocc...

The history of petroleum exploration and its outcomes in the Cretaceous Passive Margin offshore Lower Congo bear a resemblance to the exploration of the Jurassic carbonate platform in Morocco. In both cases, the same exploration strategy primarily targeted the crests of the Cretaceous (Albian) in the Pinda Formation (Lower Congo) and those of the U...

The nearly 2000 m-thick Ikakern Formation is the basal sedimentary unit in the Argana basin of Morocco, consisting of fluvial red and purple conglomerates in the lower part and interbedded red conglomerates, sandstones, siltstones and mudstones in the upper part. It unconformably overlies deformed and metamorphosed Variscan basement rocks and is un...

Multiple lines of evidence suggest that volcanic and thermogenic gas emanations from the voluminous eruptions of the Central Atlantic Magmatic Province (CAMP) triggered the end‐Triassic mass extinction. However, a comparison of the timing and duration of the biotic and environmental crises with the timing and duration of the magmatic activity is di...

The Bigoudine Fm represents one of the most widespread facies of the Moroccan Triassic on land and on the shelf with close counterparts on the conjugate Scotian shelf and onshore Atlantic Canada. We describe a magnetic polarity stratigraphy for the Bigoudine based on >300 sampling sites spanning >990 m of composite section comprised of 10 outcrop s...

Moroccan continental rift basins preceding the Jurassic opening of the central Atlantic were initiated within the Late Permian and finished in the Early Jurassic. All of these basins exhibit clastic to evaporitic red bed-dominated sequences and up to four basaltic intrusion and extrusion units of the Central Atlantic Magmatic Province (CAMP). The t...

Quantitative correlation of the Argana basin with the Newark basin APTS 2010 and other eastern North American Triassic-Jurassic basins based on paleomagnetic polarity stratigraphy and pervasive orbitally-paced lake level cycles shows that they evolved through time in a remarkably synchronized pattern during the Late Triassic. The accumulation rate...

Petroleum exploration, in several Central Atlantic Margin (CAM) basins, has demonstrated that Mesozoic synrift lacustrine sediment can source rocks for a petroleum system. In Morocco, the Triassic/Jurassic rifting of Pangea resulted in several extensional basins centered in arid climates over a palaeolatitude of about 23°N in earliest Jurassic coor...

ASTRONOMICALLY CALIBRATED GPTS FOR THE LATE TRIASSIC AND EARLY JURASSIC BASED ON THE NEWARK HARTFORD AND TAYLORSVILLE BASINS OF EASTERN NORTH AMERICA. Paul . E. Olsen1, Dennis V. Kent 2,1, Peter M. LeTourneau1, Mohammed Et-Touhami3, 1 1 Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964 USA; 2 Department of Geological Sci...

More important than the total volume of eruptives in a LIP is the concentration in time of individual eruptions with timescales relevant for environmental change. In CAMP lavas, interflow sedimentary and reddened levels are interpreted as evidence of significant time between flows of hundreds to thousands of years allowing soil development and sedi...

The end-Triassic mass extinction (ETE) at 201.4 million years ago is one of the five largest ecological disasters of the last 600 million years. Its cause is thought to be related to flood basalt eruptions of the Central Atlantic Magmatic Province (CAMP). In eastern North America, non-marine deposits recording this extinction occur below the oldest...

Eruption of the giant Central Atlantic Magmatic Province (CAMP) is temporally linked to the end-Triassic extinction (ETE) event (1,2,3,4,5). Proposed killing mechanisms for plants and marine biota have included both CO2 (4) and sulfur aerosols (3,6). Here we examine the kill mechanisms of the CAMP for land animals where we seek to explain the selec...

Cynodontipus is a Middle to Late Triassic, continental trace fossil originally described by Ellenberger in 1976 as the footprint of a hirsute cynodont synapsid. In addition to its type locality in the Middle Triassic of France, Cynodontipus has been identified from the Middle Triassic of Germany, the Middle and Late Triassic of Morocco, the Late Tr...

The Triassic-Jurassic (Tr-J) boundary marks one of the most severe Phanerozoic mass extinctions. With a turnover of at least 50% of continental biodiversity [1,2], the event set the ecological stage for the ascent of dinosaur-dominated ecosystems. In Morocco, Late Triassic-Early Jurassic predominately continental red beds formed during the Triassic...

Introduction: The end-Triassic extinction (ETE) was one of the three largest mass extinction events in the Phanerozoic at 201.4 Ma. While a bolide impact appeared to be a plausible cause of this extinction prior to this decade based on the pattern of extinction [1], what was thought to be a single modest Ir anomaly [2] and the presence shocked quar...

Late Triassic age strata of Early Mesozoic basins on the conjugate margins of Morocco and Eastern Canada were deposited for the most part in the sub-tropics based paleomagnetic evidence from multiple basins. The subtropical deposits exhibit a characteristic suite of facies, including shallow water saline lacustrine mudstones, evaporites (with thick...

Les couches rouges évaporitiques du début du Mésozoïque, formées au cours du rifting triasico-liasique du Pangea, affleurent sur une grande partie du nord du Maroc et forment le remplissage sédimentaire de plusieurs bassins partiellement démembrés par l'orogenèse alpine. Ces bassins dont la paléolatitude dans les coordonnées du début du Jurassique...

Highlights : This tour introduces to the geology of that part of the Essaouira-Agadir Basin of the Atlantic margin that was deformed and incorporated into the High Atlas Belt during the Alpine orogeny. Emphasis is put on the stratigraphy of the Triassic, which corresponds to the Central Atlantic rifting process, and of the Jurassic, during which th...

Latest Triassic and earliest Jurassic strata of the exposed Fundy (Nova Scotia) and Moroccan record the end‐Triassic extinction (ETE) and the plausibly causally related eruptions of the Central Atlantic Magmatic Province (CAMP). Outcrops of strata just below CAMP lavas in all of the basins comprise distinctive thin‐bedded layers of black, gray, red...

This field trip examines the spectacular outcrops of Late Permian, Triassic, and Jurassic age Fundy rift basin strata exposed along the shores of the Bay of Fundy, in New Brunswick and Nova Scotia, Canada. We will meet the evening of August 8, 2008 at 1 Market Square, St. John, New Brunswick, Canada and begin the fieldtrip proper on the morning of...

TSII (F3-F4 of Biron, 1982; T3-T5 of Tixeront, 1973), Ladinian?-Carnian in age, overlies TSI unconformably in both Central and Western High Atlas. It consists of fluvial and lacustrine clastic rocks with an especially well developed cyclical lacustrine sequence in the Argana basin. In the Central and Western High Atlas, an angular unconformity at l...

A predictive corollary of the Marzoli-Knight hypothesis is that the initial d13C excursion seen globally should be within or above the Moroccan CAMP but not below it. To test this prediction, we examined the carbon isotopic composition of bulk organic material (d13Corg) through palyniferous strata below the lower basalt sequence of the Central High...

Cyclostratigraphic and magnetostratigraphic correlation of rift basin strata allow correlation of individual -20 ky lacustrine cycles across 36' of paleolatitude (pi) from the tropics through the subtropics and into the temperate latitudes. Using the Newark Basin Astronomically Calibrated Geomagnetic Time Scale (NBAGPTS) as a standard, we have exam...

The early Mesozoic was characterized by extraordinary faunal and floral change in continental ecosystems. Not only did all extant groups of terrestrial vertebrates evolve, but the Early Mesozoic witnessed two of the largest mass-extinction events of the Phanerozoic, one at the end of the Permian and one at the Triassic-Jurassic boundary. The latter...

Biotic assemblages postdating the Triassic-Jurassic mass-extinction event were of very low diversity and very cosmopolitan. Hettangian age (earliest Jurassic) strata of the conjugate margin rift basins of eastern North America and Morocco preserve a gradient from lacustrine facies in the west to marine facies in the east that using the Milankovitch...

The Triassic-Jurassic (Tr-J) boundary marks one of the most severe Phanerozoic mass extinctions. With a turnover of at least 50% of terrestrial biodiversity, the event set the ecological stage for the ascent of dinosaur-dominated ecosystems. Our previous work on the Tr- J boundary in eastern North American continental rift basins and work by others...

Olsen, P.E., Whiteside, J.H., Et-Touhami, M., Kent, D.V., Fowell,

The development of Triassic to Lower Liassic clastic/evaporitic series over the epicratonic Maghreb Platform is closely associated with the eastern opening of a Tethyan marine domain between Africa and Europe. West of the platform, Morocco became separated from North America in Late Triassic times by rifting along the axis of the Proto-Atlantic Oce...

Throughout the exposed Triassic-Jurassic basins of Eastern North America and Morocco the oldest basalt flows are of HTQ composition and lie above the palynological Triassic-Jurassic boundary. In this same vast region, sedimentary strata above these flows contain several limestone-rich intervals. In eastern North America, where there are thick seque...

The Bigoudine Fm. (Argana Valley, Morocco) is Late Triassic-earliest Jurassic in age and consists of up to 1300 m of predominantly cyclical continental strata. The lowest Bigoudine (T6) consists of basal conglomerates and fluvial sandstones overlain by eolian sandstones. They are implicated as reservoir sandstones in oil and gas production in Moroc...

The Late Triassic age Blomidon Formation consists nearly entirely of massive gypsiferous mudstone and sandstones arranged into distinctive sand patch cycles, many of which show various salt dissolution features. Identical Late Triassic, cyclical, largely clastic facies are widespread in Morocco, on the conjugate margin to Nova Scotia, where Blomido...

The Late Triassic age Blomidon Formation consists nearly entirely of massive gypsiferous mudstone and sandstones arranged into distinctive sand patch cycles, many of which show various salt dissolution features. Identical Late Triassic, cyclical, largely clastic facies are widespread in Morocco, on the conjugate margin to Nova Scotia, where it freq...

The Triassic-Jurassic boundary is extremely well preserved in the rift basins formed during the incipient fragmentation of Central Pangea. In eastern North America, the most landward of these rifts have been structurally inverted and deeply eroded, revealing the deeper parts of very large rifts. As a consequence the interval around boundary is char...

Predominately continental strata of the Argana basin are divided into four at least partially unconformity bounded tectonostratigraphic sequences (TSI to TSIV), each with a characteristic set of acies and its own style of lacustrine to evaporite cyclicity. The oldest tectonostratigraphic sequence (TS-I) consists of the Ikakern Formation (T1 and T2...

In eastern North America, sedimentary interbeds and overlying strata of the basalts of the CAMP are comprised of cyclical lacustrine strata. Two of the Van Houten-type cycles above the oldest basalt flow (HTQ type) in these basins can by traced throughout not only eastern North America, but also into and throughout Morocco, overlying the oldest CAM...

The Triassic-Jurassic (Tr-J) boundary marks one of the five largest mass extinctions in the past 0.5 b.y. In many of the exposed rift basins of the Atlantic passive margin of eastern North America and Morocco, the boundary is identified as an interval of stratigraphically abrupt floral and faunal change within cyclical lacustrine sequences. A compa...

Previously very sparse biostratigraphic data suggested that the Early Mesozoic tholeiitic effusive and intrusive magmatism in the various basins of the Maghreb occurred over a long time (Ladinian-Hettangian). However, a detailed comparison of the stratigraphy underlying, interbedded with, and overlying the basalts in these basins shows not only rem...

The latest Triassic to earliest Liassic strata in the Khemisset Basin, northwestern Morocco, are subdivided into five formations: the Lower Clay Formation (LCF); the Lower Salt Formation (LSF); the Basaltic Formation (BF); the Upper Salt Formation (USF); and the Upper Clay Formation (UCF). Five salt units were identified that are informally referre...

The description of halite crystals from Moroccan Late Triassic salt formations is not limited, as it is often the case, to individualisation of milky and limpid halites and the recognition of some common crystalline facies, but it enriches the usual faciologic classification of new subdivisions that help to specify and qualify paleoenvironment reco...

An ostracod fauna is discovered for the frst time in the Oujda mountains (Morocco) triassic series. A new species is described (Lutkevichinella kristanae n.sp). These assemblages allow us to define the age (Late Norian on one hand and Late Ladinian/Early Carnian on the other). Faunal analogies with Germany lead us to place the studied levels in bra...

The origin of Moroccan Triassic salt deposit: contribution of Br geochemistry in the halite-rock from Khemisset basin (Central Morocco). The use of bromine content as genetic criterion in Late Triassic salt formations of Khemisset basin (Central Morocco) reveals that Northern Morocco was subject to intermittent seawater influx from the Tethyan doma...

The use of bromine content as a genetic criterion in Late Triassic salt formations of Khemisset basin (Central Morocco) reveals that Northern Morocco was subject to intermittent seawater influx from the Tethyan domain. A discontinuous operating connection between this domain and the Proto-Atlantic would have been located across the Moroccan Meseta...