Mineralogy and Genesis of the Polymetallic and Polyphased Low Grade Fe-Mn-Cu Ore of Jbel Rhals Deposit (Eastern High Atlas, Morocco)

Michèle Verhaert; Alain Bernard; Omar Saddiqi; Augustin Dekoninck; Mourad Essalhi; Johan Yans

doi:10.3390/min8020039

Mineralogy and Genesis of the Polymetallic and Polyphased Low Grade Fe-Mn-Cu Ore of Jbel Rhals Deposit (Eastern High Atlas, Morocco)

Michèle Verhaert, Alain Bernard, Omar Saddiqi, Augustin Dekoninck, Mourad Essalhi, Johan Yans

Institute of Life-Earth-Environment

Research output: Contribution to journal › Article › peer-review

44 Downloads (Pure)

Abstract

The Jbel Rhals deposit, located in the Oriental High Atlas of Morocco, hosts a polymetallic Fe-Mn-Cu ore. Large metric veins of goethite and pyrolusite cut through Paleozoic schists that are overlaid by Permian-Triassic basalts and Triassic conglomerates. The genesis of this deposit is clearly polyphased, resulting from supergene processes superimposed over hydrothermal phases. The flow of Permian-Triassic basalts probably generated the circulation of hydrothermal fluids through the sedimentary series, the alteration of basalts and schists, and the formation of hydrothermal primary ore composed of carbonates (siderite) and Cu-Fe sulfides. Several episodes of uplift triggered the exhumation of ores and host rocks, generating their weathering and the precipitation of a supergene ore assemblage (goethite, pyrolusite, malachite and calcite). In the Paleozoic basement, Fe-Mn oxihydroxides are mostly observed as rhombohedral crystals that correspond to the pseudomorphose of a primary mineral thought to be siderite; goethite precipitated first, rapidly followed by pyrolusite and other Mn oxides. Malachite formed later, with calcite, in fine millimetric veins cutting through host-rock schists, conglomerates and Fe-Mn ores.

Original language	English
Article number	39
Number of pages	23
Journal	Minerals
Volume	8
Issue number	2
DOIs	https://doi.org/10.3390/min8020039
Publication status	Published - 25 Jan 2018

Keywords

Moroccan High Atlas
supergene deposits
goethite
gossan
weathering
Weathering
Goethite
Gossan
Supergene deposits

Access to Document

10.3390/min8020039

MineralogyGenesisPolymetallicPolyphasedFinal published version, 3.49 MBLicence: CC BY

Cite this

@article{e7aac940eac4429499dc6c13b6f207cb,

title = "Mineralogy and Genesis of the Polymetallic and Polyphased Low Grade Fe-Mn-Cu Ore of Jbel Rhals Deposit (Eastern High Atlas, Morocco)",

abstract = "The Jbel Rhals deposit, located in the Oriental High Atlas of Morocco, hosts a polymetallic Fe-Mn-Cu ore. Large metric veins of goethite and pyrolusite cut through Paleozoic schists that are overlaid by Permian-Triassic basalts and Triassic conglomerates. The genesis of this deposit is clearly polyphased, resulting from supergene processes superimposed over hydrothermal phases. The flow of Permian-Triassic basalts probably generated the circulation of hydrothermal fluids through the sedimentary series, the alteration of basalts and schists, and the formation of hydrothermal primary ore composed of carbonates (siderite) and Cu-Fe sulfides. Several episodes of uplift triggered the exhumation of ores and host rocks, generating their weathering and the precipitation of a supergene ore assemblage (goethite, pyrolusite, malachite and calcite). In the Paleozoic basement, Fe-Mn oxihydroxides are mostly observed as rhombohedral crystals that correspond to the pseudomorphose of a primary mineral thought to be siderite; goethite precipitated first, rapidly followed by pyrolusite and other Mn oxides. Malachite formed later, with calcite, in fine millimetric veins cutting through host-rock schists, conglomerates and Fe-Mn ores.",

keywords = " Moroccan High Atlas, supergene deposits, goethite, gossan, weathering, Moroccan High Atlas, supergene deposits, goethite, gossan, weathering, Weathering, Goethite, Gossan, Supergene deposits",

author = "Mich{\`e}le Verhaert and Alain Bernard and Omar Saddiqi and Augustin Dekoninck and Mourad Essalhi and Johan Yans",

note = "Funding Information: Acknowledgments: Mich{\`e}le Verhaert thanks the Belgian Fund For Scientific Research (FNRS), for providing her with a FRIA PhD grant. We thank the administration of Bou Arfa for field access and facilities to the mines. Many thanks are due to Ga{\"e}tan Rochez (UNamur) for the field support and pictures. Ludovic Lafforgue is thanked for his help on the field. We also express our gratitude to the reviewers for their constructive comments that significantly improved the manuscript. Publisher Copyright: {\textcopyright} 2018 by the authors. Licensee MDPI, Basel, Switzerland. Copyright: Copyright 2018 Elsevier B.V., All rights reserved.",

year = "2018",

month = jan,

day = "25",

doi = "10.3390/min8020039",

language = "English",

volume = "8",

journal = "Minerals",

issn = "2075-163X",

publisher = "Multidisciplinary Digital Publishing Institute (MDPI)",

number = "2",

}

TY - JOUR

T1 - Mineralogy and Genesis of the Polymetallic and Polyphased Low Grade Fe-Mn-Cu Ore of Jbel Rhals Deposit (Eastern High Atlas, Morocco)

AU - Verhaert, Michèle

AU - Bernard, Alain

AU - Saddiqi, Omar

AU - Dekoninck, Augustin

AU - Essalhi, Mourad

AU - Yans, Johan

N1 - Funding Information: Acknowledgments: Michèle Verhaert thanks the Belgian Fund For Scientific Research (FNRS), for providing her with a FRIA PhD grant. We thank the administration of Bou Arfa for field access and facilities to the mines. Many thanks are due to Gaëtan Rochez (UNamur) for the field support and pictures. Ludovic Lafforgue is thanked for his help on the field. We also express our gratitude to the reviewers for their constructive comments that significantly improved the manuscript. Publisher Copyright: © 2018 by the authors. Licensee MDPI, Basel, Switzerland. Copyright: Copyright 2018 Elsevier B.V., All rights reserved.

PY - 2018/1/25

Y1 - 2018/1/25

N2 - The Jbel Rhals deposit, located in the Oriental High Atlas of Morocco, hosts a polymetallic Fe-Mn-Cu ore. Large metric veins of goethite and pyrolusite cut through Paleozoic schists that are overlaid by Permian-Triassic basalts and Triassic conglomerates. The genesis of this deposit is clearly polyphased, resulting from supergene processes superimposed over hydrothermal phases. The flow of Permian-Triassic basalts probably generated the circulation of hydrothermal fluids through the sedimentary series, the alteration of basalts and schists, and the formation of hydrothermal primary ore composed of carbonates (siderite) and Cu-Fe sulfides. Several episodes of uplift triggered the exhumation of ores and host rocks, generating their weathering and the precipitation of a supergene ore assemblage (goethite, pyrolusite, malachite and calcite). In the Paleozoic basement, Fe-Mn oxihydroxides are mostly observed as rhombohedral crystals that correspond to the pseudomorphose of a primary mineral thought to be siderite; goethite precipitated first, rapidly followed by pyrolusite and other Mn oxides. Malachite formed later, with calcite, in fine millimetric veins cutting through host-rock schists, conglomerates and Fe-Mn ores.

AB - The Jbel Rhals deposit, located in the Oriental High Atlas of Morocco, hosts a polymetallic Fe-Mn-Cu ore. Large metric veins of goethite and pyrolusite cut through Paleozoic schists that are overlaid by Permian-Triassic basalts and Triassic conglomerates. The genesis of this deposit is clearly polyphased, resulting from supergene processes superimposed over hydrothermal phases. The flow of Permian-Triassic basalts probably generated the circulation of hydrothermal fluids through the sedimentary series, the alteration of basalts and schists, and the formation of hydrothermal primary ore composed of carbonates (siderite) and Cu-Fe sulfides. Several episodes of uplift triggered the exhumation of ores and host rocks, generating their weathering and the precipitation of a supergene ore assemblage (goethite, pyrolusite, malachite and calcite). In the Paleozoic basement, Fe-Mn oxihydroxides are mostly observed as rhombohedral crystals that correspond to the pseudomorphose of a primary mineral thought to be siderite; goethite precipitated first, rapidly followed by pyrolusite and other Mn oxides. Malachite formed later, with calcite, in fine millimetric veins cutting through host-rock schists, conglomerates and Fe-Mn ores.

KW - Moroccan High Atlas

KW - supergene deposits

KW - goethite

KW - gossan

KW - weathering

KW - Moroccan High Atlas

KW - supergene deposits

KW - goethite

KW - gossan

KW - weathering

KW - Weathering

KW - Goethite

KW - Gossan

KW - Supergene deposits

UR - http://www.mdpi.com/2075-163X/8/2/39/html

UR - http://www.scopus.com/inward/record.url?scp=85041127396&partnerID=8YFLogxK

U2 - 10.3390/min8020039

DO - 10.3390/min8020039

M3 - Article

SN - 2075-163X

VL - 8

JO - Minerals

JF - Minerals

IS - 2

M1 - 39

ER -

Mineralogy and Genesis of the Polymetallic and Polyphased Low Grade Fe-Mn-Cu Ore of Jbel Rhals Deposit (Eastern High Atlas, Morocco)

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Geological and geochemical constrains on the genesis of the sedimentary-hosted Bou Arfa Mn(-Fe) deposit (Eastern High Atlas, Morocco)

Characterization and (U-Th-Sm)/He dating of Moroccan supergene ore deposits : New insights to unravel the periods and potential causes of weathering processes.

Cite this

Mineralogy and Genesis of the Polymetallic and Polyphased Low Grade Fe-Mn-Cu Ore of Jbel Rhals Deposit (Eastern High Atlas, Morocco)

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Research output

Geological and geochemical constrains on the genesis of the sedimentary-hosted Bou Arfa Mn(-Fe) deposit (Eastern High Atlas, Morocco)

Student theses

Characterization and (U-Th-Sm)/He dating of Moroccan supergene ore deposits : New insights to unravel the periods and potential causes of weathering processes.

Cite this