Le volcanisme alcalin tertiaire et quaternaire du moyen atlas (Maroc): chronologie K/Ar et cadre géodynamique

Harmand, C.; Cantagrel, J. M.

doi:10.1016/0899-5362(84)90019-8

Cited by 62 publications

(45 citation statements)

References 3 publications

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“…They cover an area of about 1500 km2 and are predominantly situated within the Tabular Middle Atlas, although lesser amounts of basalt are present within the Folded Middle Atlas and the High Moulouya Rise. Harmand & Cantagrel (1984) obtained K-Ar ages ranging from 1.5 Ma to 0.5 Ma from these rocks. The timing of the oldest eruption coincides with the beginning of the present regional stress field in the Rif as reported by several workers (e.g., Kit Brahim & Chotin, 1984;Morel 1989).…”

Section: Geological Settingmentioning

confidence: 99%

Active tectonism in the intracontinental Middle Atlas Mountains of Morocco: synchronous crustal shortening and extension

Gomez

Barazangi

Bensaid

1996

JGS

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Geological field observations are integrated with digital topography, LANDSAT imagery, and earthquake focal mechanisms to investigate the Middle and Late Quaternary tectonism in the intracontinental Middle Atlas mountain belt in northern Morocco. The NE-SW-trending Middle Atlas Mountains, approximately 80 km in width and about 200 km long, are part of the Atlas system of northwestern Africa and represent an inverted rift that developed into an intracratonic mountain system in the foreland of the Alpine collisional zone. The Middle Atlas is composed of two provinces, the Folded and Tabular Middle Atlas, representing the palaeo-rift and a flank of the palaeo-rift, respectively. Evidence for Late Quaternary tectonism is provided by the analysis of stream morphology in addition to geological relations. Kinematic analysis of fault-slip data and earthquake focal mechanisms demonstrate the coexistence of both extensional and compressional deformation in different areas of the Middle Atlas with a common sinistral component of slip along NE-SW-striking fault zones. Compressional features dominate the Folded Middle Atlas, whereas extension predominates in the Tabular Middle Atlas. Extension is also manifested by widespread Middle to Late Quaternary alkali volcanism. The observed kinematic variations appear to correlate with the Mesozoic palaeogeography; one possible model may involve tectonic escape. This suggests that differences in the structures inherited from the Mesozoic and Palaeozoic may influence the responses of the different regions to the Cenozoic Alpine collision between Europe and northwest Africa.

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Section: Geological Settingmentioning

confidence: 99%

Active tectonism in the intracontinental Middle Atlas Mountains of Morocco: synchronous crustal shortening and extension

Gomez

Barazangi

Bensaid

1996

JGS

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“…K-Ar datings of lavas have been published by Harmand & Cantagrel (1984), Berrahma (1995), Rachdi (1995) andEl Azzouzi et al (1999). The petrogenesis and the tectonic setting of the alkali basalts and related lavas have been discussed by a number of authors, including Bernard-Griffiths et al (1991), Berrahma (1995), Rachdi (1995), Mourtada et al (1997), El Azzouzi et al (1999, Maury et al (2000), Coulon et al (2002), Savelli (2002), Duggen et al (2005), Teixell et al (2005) and Missenard et al (2006).…”

Section: The Cenozoic Volcanic History Of the Atlas Systemmentioning

confidence: 96%

The Atlas System

Lamotte

Zizi

Missenard

et al.

Lecture Notes in Earth Sciences

118

114

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“…Locally covering these strata are Plio-Quaternary (ca. 14.6-0.5 Ma) alkaline basaltic lava flows (Harmand and Cantagrel 1984;Duggen et al 2009;Wittig et al 2010).…”

Section: Geologic Settingmentioning

confidence: 97%

Geology, Fluid Inclusions, and Geochemistry of the Aouli Sulphide ± Fluorite ± Barite Vein Deposit (Upper Moulouya District, Morocco) and Its Relationships to Pangean Rifting and Opening of the Tethys and Central Atlantic Oceans

Bouabdellah¹,

Margoum²

2016

Mineral Deposits of North Africa

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The Aouli Pb-Zn ± F ± Ba deposit in the upper Moulouya district of central Morocco consists of an array of multi-kilometer, transtensional, sub-vertical veins grouped into four main systems referred to as Aouli, Ansegmir, Sidi Said, and Sidi Ayad. Collectively, these veins produced *10 Mt of ore at a grade of 5 % Pb. Host rocks are a succession of folded and low-to medium-grade metasedimentary and minor metavolcanic rocks of Cambro-Ordovician age locally intruded by the multiphase ca. *330-319 Ma Aouli batholith. The veins occur either within the Aouli granitic intrusion (i.e., Ansgemir), Cambro-Ordovician schistose pelites (i.e., Aouli, Sidi Said), or both (i.e., Sidi Ayad). Overall, the orebodies exhibit very low Zn/Pb ratios, and contain 150-600 g/t Ag and 200-700 g/t Bi. Hydrothermal alteration is weakly to moderately developed in the vicinity and surrounding the veins, and is dominated by intense silicification coupled with minor sericitization, both types being superimposed on regional propylitic alteration. The sulphide mineralization consists principally of varying proportions of galena and sphalerite, and to a much lesser extent chalcopyrite and pyrite. Gangue minerals include multiple generations of quartz and paragenetically later fluorite and barite. Combined fluid inclusion data together with stable and radiogenic isotopic constraints indicate that the Aouli vein-type sulphide ± fluorite ± barite mineralization formed during the Permian-Jurassic contemporaneously with Pangean rifting and subsequent opening of the Tethys and Central 291Atlantic oceans. Mixing at the basement-cover interface of an ascending, deep-seated fluid that equilibrated with Hercynian crystalline basement rocks, and formation and/or meteoric water, is proposed to have triggered ore deposition.

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Le volcanisme alcalin tertiaire et quaternaire du moyen atlas (Maroc): chronologie K/Ar et cadre géodynamique

Cited by 62 publications

References 3 publications

Active tectonism in the intracontinental Middle Atlas Mountains of Morocco: synchronous crustal shortening and extension

Active tectonism in the intracontinental Middle Atlas Mountains of Morocco: synchronous crustal shortening and extension

The Atlas System

Geology, Fluid Inclusions, and Geochemistry of the Aouli Sulphide ± Fluorite ± Barite Vein Deposit (Upper Moulouya District, Morocco) and Its Relationships to Pangean Rifting and Opening of the Tethys and Central Atlantic Oceans

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