field trip in morocco - society of economic geologists · 2019-11-07 · seg student chapter uqac....

SEG Student Chapter UQAC. Field Trip Report. Field trip in Morocco 2019

SEG Student Chapter Of University Of Quebec In Chicoutimi

FIELDTRIP REPORT

Field trip in Morocco :

Visit of VMS type deposits, skarn type deposits, Cu porphyry,

Ni-Co deposits, Ag-Pb-Zn epithermal veins types deposits

May 11th to May 21th 2019


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OUR SPONSORS


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Summary: OUR SPONSORS .............................................................................................................................. ii

1 Participants of the field trip ......................................................................................................... 4

2 Detailed program of the field trip and contact ............................................................................. 5

3 Budget and expenses ................................................................................................................... 7

4 Excursion ..................................................................................................................................... 8

4.1 May 12th : Gorges of Ourika : .............................................................................................. 8

4.2 May 13th: Draa El Sfar ore deposits and Guemassa plants ................................................. 9

4.3 May 14th Imiter : Ag-Hg vein type deposit ........................................................................ 11

4.4 May 15th Gorges of Todhra and Dadès .............................................................................. 13

4.5 May 16th Cu porphyry ore deposit of Bleida ..................................................................... 15

4.6 May 18th : Ni-Co magmatic ore deposit of Bou Azzer ...................................................... 17

4.7 May 19th: Amensif Mine (Cu-Pb-Zn ± Au-Ag deposit) .................................................... 19

5 ACKNOWLEDGEMENTS ...................................................................................................... 21

6 REFERENCES .......................................................................................................................... 21


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1 Participants of the field trip

Name Firstname Mail Contact Status Date Of

Birth Nationality

Cote Denis [email protected] Ing Geo 13/11/1959 Canada

Huguet Julien [email protected] M.Sc.Research 24/06/1994 France

Kieffer Marie [email protected] M.Sc.Research 17/01/1994 France

Dour Maxime [email protected] M.Sc.Pro 16/11/1995 France

Girard Eve [email protected] 3rd B.Sc 26/06/1996 Canada

Perron-Desmeules Laura-Pier laura-pier.perron-

[email protected] 3rd B.Sc 10/09/1987 Canada

Chiasson Louis-Pierre

[email protected] 2nd B.Sc 25/06/1997 Canada

Gendron Marylou [email protected] 2nd B.Sc 27/09/1994 Canada

Montero Alexandre [email protected] 2nd B.Sc 18/08/1996 Canada

Tremblay Anick [email protected] 2nd B.Sc 18/12/1997 Canada

Boudreault Steeve [email protected] 1st B.Sc 18/11/1977 Canada

Desforges Yann [email protected] 1st B.Sc 28/10/1997 Canada

Figure 1: Group photography in front of the open pit of Bleida mine (SOMIFER). From left to right : Julien Huguet, Marie Kieffer, Yan Desforges, Marylou Gendron, Eve Girard, Laura-Pier Perron-Desmeules, Alexandre Montero, Louis-Pierre Chiasson, Anick Trembaly, Maxime Dour, Steve Boudreault and Denis Côté, accompanied by one of the geologist of the mine and Hsaine Baoutoul (Chief Geologist). Picture by Hassan Boussouf (Geo and Chief of Safety Security department).


2 Detailed program of the field trip and contact

Date Departure Arrival Visit and activities

City Hotel adress Dist & Time Name Location Contact

May 10 - 11th

Pierre-Eliott-Trudeau Airport, Montreal (May 10th, 19:05)

Mohammed VI airport, Casablanca (May 11th, 7:30)

Hotel les saisons, 19, Rue EL ORAIBI JILALI Av. des F.A.R. Casablanca, Maroc

7h25 of Flight + 30mn of driving between airport and Hostel

Visit of Casablanca with our guide

May 12th Casablanca Marrakech Tempoo Hotel. Rue Abou Bakr

Seddiq, Marrakesh 40000 242km (4h00 via A7) Visit of the Valley of Ourika , Anti-Atlas Tagadirte : 31° 22' 55'' N ; 7°46'44''.W

May 13th Marrakech Ouarzazate

Al Baraka des Loisirs. 380 Rue Al-Mansour Ad-Dahbi, Ouarzazate 45000, Maroc

240km (5h00 via P2117 and N9)

Draa El Sfar VMS type deposit and Hajar (Guemassa factory)

31°42'44''N ; 8°07'56''W / Guemassa factory, P2010 road (31°22'1''N ; 8°03'11''W)

Mohammed Outhounite (CMG- Draa El Sfar) & Badr Aznag (CMG-Hajar)

May 14th Ouarzazate Boumalne-Dadès La Kasbah de Dadès03/10/2019

N10, Boumalne Dades, Maroc 160km (3h30 via N10) Silver mine of Imiter (SMI) Imiter Mine, Imiter District, Tinghir Province, Drâa-Tafilalet. 31°20'44''N ; 5°43'54''W

Salim El Mouden (SMI)

May 15th

Boumaine Dadès Ouarzazate

Al Baraka des Loisirs. 380 Rue Al-Mansour Ad-Dahbi, Ouarzazate 45000, Maroc

190 km (3h10 via R704 and N10) Todhra and Dadès Gorges

15 km North to Tinghir . (31°35'03''N ; 5°35'28''W) / 20km North from Boumalne Dadès (31°27'13'' N ; 5°58'11''W)

May 16th Ouarzazate Agdez Hotel Kissane. hay kissane

agdez, Maroc 250 km (3h30 via N9 and R108) Bleida copper mine

Bleida Mine, Bleida,(Bou Azzer District), Tazenakht, Ouarzazate Province, Drâa-Tafilalet 30° 21' 20'' North , 6° 27' 30'' West

Hassan Boussouf (SOMIFER) & Hsaine Baoutoul (SOMIFER)

May 17th Agdez Agadir

Hotel Argana Agadir. Boulevard Mohamed V B P 93، Agadir 80000

359km (5h30 via R108 and via N10 after Tazenaht) Ni-Co mine of Bou Azzer

Bou Azzer, (Bou Azzer District), Tazenakht, Ouarzazate Province, Drâa-Tafilalet. 31°4'0'' N ; 7°1'59''W

Abelhak Karfal (CTT) & Said Ilmen (CTT)

May 18th Agadir

Hotel Argana Agadir. Boulevard Mohamed V B P 93، Agadir 80000

Day of visit in Agadir

May 19th Agadir Marrakech Tempoo Hotel. Rue Abou Bakr

Seddiq, Marrakesh 40000

235 km (5h40 via A7 and R203 from Asni to Amensif deposit, and via R203 from Amensif to Marrakech)

Ag-Bi-Cu-Pb-S ore deposit of Amensif Amensif deposit, Azegour, Tata Province, Souss-Massa. 31°09'N ; 7°49'48''W

Abdelaali Khalife (CMG)

May 20th Marrakech Casablanca

Hotel les saisons, 19, Rue EL ORAIBI JILALI Av. des F.A.R. Casablanca, Maroc

Return to Casablanca. End of the field trip


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3 Budget and expenses

The budget of the year and the expenses and funds attributed to the field trip are described below.

Note that the expenses of the flight tickets are not in the table since they were at the expense of the student.

As the price of the ticket raised drastically to an average of 850 CAD$, the committee decided to refund

the participant after the field trip with an equivalent of 40 CAD$ per day to absorb the daily expenses for

food and accommodations. Funding of the field trip was collected from autumn 2018 to spring 2019. The

Stewart R. Wallace and most of the sponsorship funds were entirely used for the field trip. It was decided

to keep funds to prepare the as good as possible the activities of the 2019 – 2020 year.

Tableau 1: Detailed expenses and funding of the field trip in Morocco (11th -21th May 2019).

Funds Expenses (CAD)

Sept 22, 2018 Annual general meeting 37,06$

140,00$

177,06$

Oct 17 - 18, 2018 Xplor 2018 Conferences 1 542,00$

1 542,00$

Nov 19 - 22, 2018 Québec Mines + Energie 2018 Conference 5 236,00$ 1 409,63$

1 325,37$

84,26$

Nov 12, 2018Conference by Stephanie Lavaure, Project

Geologis (Ariane Phosphate)-$

March 2019 Carrefour des Sciences Conferences 1 022,37$

May 12 - 21, 2019 Field trip in Marocco 10 536,42$ 14 168,72$

Sept 2018 - 2019 Administrative Fees 43,28$

5 123,85$

1 285,73$

3 500,00$

3 776,18$

3 879,86$

5 150,00$

626,84$ 241,15$

650,25$

471,28$

17 314,42$ 16 681,06$

4695,44

Student membership fees (28members)

Lunch food provided

Professionnals registration

Refund Lecturer

Refund student transport costs

Sponsorship private fund

University and city grants

Activities

Former bank account amount ( 28 Sept 2018)

633,36$

Total remaining for the next committee (16 Sept 2019) 5 328,80$

Bourse Stewart R. Wallace SEG

Kiosk activity

Promotionnal gear

Presents for Managem geologists

Hotels (riads, guest rooms) for 11 nights

Transport (van 16 places)

Food and accomodations

Total mouvement

Balance


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4 Excursion

4.1 May 12th : Gorges of Ourika :

The second day of the field trip began with the encounters of the group with our guide Rajae

Hammouch, project manager for MANAGEM. The rest of the day was dedicated to the travel between

Casablanca and Marrakech. As we had no visit of mine planned for the day, we decided to hike in the

Ourika valley of the High Atlas mountains. It was the occasion for the group to discover the beautiful

landscape of Atlas and take some energy before the next long days.

Figure 2: Hiking day in Ourika valley (High Atlas). A: Group photography in front of the valley of Ourika. B: Tagardite, a typical village of High Atlas mountains, in Ourika valley. C: Panorama of the valley. D: Water fall giving birth of the ourika oued (river of semi-arid climate of north Africa)


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4.2 May 13th: Draa El Sfar ore deposits and Guemassa plants

On this 3rd day of excursion, the group set off in the early morning to the Draa Sfar mine, located 30km

north of Marrakech to meet the project geologist Mohammed Outhounite (Geo, CMG). The tour began

with a lecture on the geology of the site and extraction methods, followed by a visit to the core shack

(Figure 3A-B). The Draa El Sfar deposit was discovered in 1949 by the presence of gossan on the surface.

The first operation took place from 1978 to 1981. An exploration campaign took place again by

geophysics in 1997 conducted by the BRGM and REMINEX by geophysics and drilling. The discovery

of new extensions revived the exploitation in 2004. Production currently stands at 1,500t/day at an

average grade of 1.5% to 3%Cu with a total production of 4Mt of Cu since 2004

The Dra El Sfaar deposit is located in the central part of Jebilet massif, it represents an NS corridor 100km

long and 25km wide rich in VMS deposits. It extends from the Dra El Sfaar site to the Hajar deposit. The

formation of these deposits is dated to 350Ma, that is synchronous of rifting episodes during the varisc

orogenesis. Several deposit are associated to this event, like the class mondial ore deposit of the Iberian

Pyrite Belt (Neves-Corvo, Rio Tinto) and the Massif Central deposits in France.

Massive sulphides formed in the volcano-sedimentary formations of Saghlef of Tournaisian-Visean age.

The formations consist of a succession of rhyoliths and mafic lava flows and sills interspersed in siltstones

(Lescuyer et al, 1998). Primary mineralization was subsequently deformed by a first episode of E-W

compression, with the formation of shear zones, ductile faults resulting in the verticalization and bulging

of massive sulphides. The deposit consists in three mains lens with different mineralogical content. The

South lens is Zn rich with sphalerite, galena and chalcopyrite, grading 4%Zn and 1,4%Pb showing

enrichment near the surface, copper is more present at depth (Figure 3C). The north lenses are copper

rich with chalcopyrite, pyrrhotite, pyrite grading an average of 3% to 8%Cu locally (Figure 3D). Some

gold values are associate to copper in the richer part that are brecciated. The alteration is characteristic of

VMS, it consists in silicification and pervasive Fe-chlorite.

In the afternoon, we met Badr Aznag to visit the research center of REMINEX in Guemassa, and the

hydrometallurgical plants. REMINEX is working on many projects with the objectives to improve the

recovery of ore, and to develop new process of geometallurgy. They use many high-tech instruments like

LA-ICP-MS, ICP-AES, MEB + EDS coupling, DRX. They have several applications like research of

REE, PGE, trace element in ore, recovery of the old tailing of Bou Azzer, rich in cobalt, by producing

cathodes.

The hydrometallurgical plant started operation in 1992. The mill has a daily average capacity of 4500t or

1.4Mt by year. They use a differential flottation process to produce 3 concentrates of Zn, Pb and Cu by

using a mix of ore of the different deposits of the Jebilet district with 45% Zn, 22%Cu and 65%Pb. The

Draa El Sfar deposit count for almost 70% of the ore used and is stored in one unique silo. They first

separate lead by density, then use copper sulfide and lime to increase pH and separate copper from zinc.

The mill is finaly able to produce per year 80 000t of Zn concentrate, 17 000t of Pb and 17 000t of Cu.


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Figure 3: Visit of Draa El Sfar deposit and Guemassa plants. A: Photography of the core shack of CMG in the Draa El Sfaar deposit. B : SThe SEG student studying the core of the south lens of Dra El Sfar deposit. C: Quarte vein brecciated by sphalerite and mineralization of sphalerite and galena from the south lens. D: Chalcopyrite-pyrrhotite-pyrite mineralization of the north lenses. E: Short conference in the control station of the mill in the Guemassa plant.


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4.3 May 14th Imiter : Ag-Hg vein type deposit

On this 4th day of field trip, we drived from Boumaine Dadès to Imiter. The tour began by a conference

on the geology of the site, presented by Salim El Mouden (Geo, SMI), and the visit of geological center,

then had the opportunity to descend into the underground galleries.

The Imiter mine is operated by the Metallurgy Company of Imiter (SMI), which is a subsidiary of

Managem. The deposit is known since the 8th century, where silver was extracted for the manufacture

of the first silver pieces until the 13th century. The company SMI once again operates the old tailings,

which can hold 300 to 500ppm of Ag.

The deposit is located in the Anti-Atlas, in the Precambrian rocks of the "Boutonnière" belt. Imiter

represent a world class deposit of Ag with 8.5Mt. Its current production amounts to 15.000t of ore per

month with grades of up to 50% Ag. The last calculations of reserves amount to 4.000t of Ag.

The deposit is mainly controlled by E-W extensional right-slip regional fault like the Imiter fault.

Mineralization is controlled by N110-N120 structures, which form subvertical dipping south deformation

corridors and by transtension relays, along overlapping NE-SW faults, giving it a lenticular appearance.

The main Ag deposit set in south-dipping tension veins, generated by dextral extensive deformation. The

Ag contents show higher values in contact with Precambrian pelitic and sandstones formations. The Ag

content increases gradually from 100ppm in the outer halo to 5%Ag at the core. Mineralization results in

a paragenesis native silver, Proustite, Acanthite, Cinnabar, Cerusite, and Imiterite. Imiterite (Ag2HgS2) is

a specific mineral species, discovered and described in Imiter

In the Imiter 1 sector, mineralization takes place in fault zones in contact with north-dipping mafic

dykes, and Precambrian pelites. The alteration is expressed by a halo of kaolinite - illite and chlorite

around the mineralized areas. Moreover Tuduri et al. (2005) reported the alteration manifests itself in an

intense dissolution of carbonates, heading to the creation of voids, leading to local enrichment in Ag.

The deposition of mineralization is done by "flashing", which is a destabilization of the fluid by a sudden

drop in pressure, causing a boil and separation of ligands and metals. Several hypotheses have been

proposed to explain the origin of metals; (1) a remobilization of primary mineralization and metals from

sediments, (2) synchronous mineralization to magmatic activity dated to 550-3Ma (Levresse et al. 2004).


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Figure 4: Visit of Imiter mine (SMI). A: The group in front of the geological center of Imiter. B: Native silver of Imiter. C: Photography of the quartz veins of the E-W shear zone. D: Tension quartz vein dipping south, showing a dextral opening displacement. E: Filament of natve silver with proustite and dolomite.


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4.4 May 15th Gorges of Todhra and Dadès

The 5th day of the field trip gave the opportunity to visit in the morning the gorges of Dades located

30 minutes drive north of Boumaine Dadès, and then to head to the Todhra Gorge in the afternoon (Figure

5). The Dades Gorge was formed by erosion of Toarcian-age carbonate formations at Eocene during

alpine orogenesis. These formations consist of a sequence of sandstone and shales-limestone rock

deposits of the Tagoudite Formation. The upper limit being marked by the appearance of limestone

channels of the Formation of Tafraout (Ettaki, 2003).

The interest of the day was based on the observation and description of the sedimentary sequence

characteristic of platform border environments. The environment of the Dadès Gorge presents sandstone

sequences, interspersed with green, verticalized and eroded shales beds. The forms created are commonly

called the "Atlas brain" and correspond to a differential erosion of sedimentary deposits.

The Todhra Gorge consists of high limestone cliffs, dug by the Oued Todhra for several thousand years.

They have stratified decametric bars of oolithic limestone, in which lamellibranch biostromes can be

found, reflecting a shallow carbonate platform environment.

The layers have a strong dip to the south, resulting from the apparition of fault and overlap caused by

major E-W accidents in the late Cretaceous, early Eocene (Montenat et al, 2005).

The Todhra Valley retains a remarkable architectural heritage in many aspects, showing some forty

fortified villages called Ksour.


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Figure 5: Hiking day in the Dadès Gorges and Todhra Gorges. A: Denis Côté giving a short course about sedimentology in front of the cross-bedded sandstone formation of the Tagoudite formation in the Dadès gorges.B: Landscape photography showing the dipping South-Est formation with differential erosion of sandstone and siltstone sediment, with the “Atlas Brain” forms in background. C: Photography of the group as scale in front of cretaceous carbonate formation in the Todhra Gorges. E: Panoramic photography of the same carbonate formation showing the steeply dipping to the south-est.


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4.5 May 16th Cu porphyry ore deposit of Bleida

The journey of visit of mine site of Bleida began with a conference done by Hassan Boussouf and

Hsain Baoutoul on the safety and security on the site and the effort of MANAGEM to increase his security

politicy. The site beneficit of the recent innovation in term of safety and is certified on environmental

norms ISO 14001:2004 and security norm OHSAS 18001:2007.

The mine of Bleida is currently runned by Somifer which is a subsidiary company of the Managem

Group. Gold was the main product extracted until 2016. At that time gold extraction ceased and was

replaced by copper extraction due to economic conditions. Since then, the mine is producing 3 000 tons

of concentrate (20 % Cu) made from the treatment of 1 000 000 tons of ore per year. Exploitation of the

pits is contracted out by another company and treatment of the ore is performed 23 km away in the mine

facility by Somifer.

The mine is located in the Anti Atlas Central, in the SE corner of the NE-SW Bou Azzer exhumed

anticlinal inlier, which measure 60 per 20 km. Three open pits are currently under mining operation

including the ore deposit Jbel Laassen from which most of the ore is extracted (Figure 6).

The sedimentary cover is made of limestones and sandstones. The mineralisation has been remobilised

over time and was initially located in the lower part of topographic lows delimited by sandstones horsts.

Now, one part of the mineralisation is stratiform and is located in the lower part of the limestones which

are rich in organic material. The main part is located in the sandstones below the limestones. It is

associated to the hinges of anticlinals which contained hydrocarbons before the migration of the

mineralisation. Ore can be found as disseminated grains, nodules or veins with no preferential orientation.

The ore process starts with a primary crushing followed by secondary (T80 = 25 mm) and tertiary

(T80 = 10 mm) crushing. Then the ore is grinded in order to obtain a size of 75 to 80 micrometers. The

fifth step is flotation followed by filtration which separate Cu concentrate from water. The latter goes in

a retention basin before being redirected in the loop. That way 60 % of the water is recycled and only 40

% of new water has to be pumped from the groundwater table. That water management is critical in an

environment such as the one around the mine where access to water is limited.


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Figure 6 : Visit of Bleida mine. A: Panoramic picture of the open pit. B: Detailed phorography of the open pit with the different bloc level of exploitation. C; Group photography with the SEG student and the geologist working on the site. D: Copper mineralization expressed as chrysocole. E: Bedded and zoned mineralization of bornite, chalcopyrite and pyrrhotite.


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4.6 May 18th : Ni-Co magmatic ore deposit of Bou Azzer

On this 8th day of field trip, we traveled in the morning to Bou Azzer mine, located in the eponym

district, where we met Saïd Ilmen, the Chief geologist. The Bou Azzer mine is operated by the Tifnoute

Tiranine Company since 1976, which is a subsidiary of Managem. Located at 120km south to Ouarzazate,

Bou Azzer is one of the oldest mine of Managem, in operation since 1928. It constitutes one of the rarest

deposit to produce cobalt as principal substance, exported in destination to the hydrometallurgical plant

in Guemassa, and gold as by-product. The annual production is about 150 000 t of ore with grades of 1%

Co, 1% Ni and 3 g/t Au in the Bou Azzet District, with 1, 600t of cobalt produced in 2008 (U.S Geological

Society, 2009).

The Ni-Co ore deposit of Bou Azzer is located in the central part of the accident of Anti-Atlas, it

represent a geological window (“boutonnière”) into paleoproterozoïc basement including gneiss,

amphibolites and schist. They are intruded and covered by the Cryogenian sequences comprising

epicontinental sedimentary, volcanoclastic rocks and the ophiolitic sequence comprising serpentinites,

gabbros and quarte-diorites (Figure 7). All the formation are deformed by the main Pan-African

shortening tectonic event, and overlain by the volcnoclastic pile of the Ediacaran Ouarzazate supergroup.

The mineralisation takes places in several environment inside the “boutonnière” of ophiolites; (i) in a

swarm of NE-SW quartz veins steeply dipping in the ophiolite sequence, (ii) on the contact of

serpentinites in a graben system at the Aghbar site.

The mineralisation of cobalt is characterized by quartz veins associated with cobalt bearing mineral

or banded, massive or disseminated texture. The common mineralogy of the deposit consist of (i) Co-Ni

arseniures like skuttérudite, safflorite, löllingite, rammelsbergite , (ii) sulfo-arseniures like cobaltite,

gersdorffite and arsenopyrite. Electrum and native gold can be found in the shear zone associated with a

conjugate fault system related to the N#5 vein oriented NE-SW, and at the contact between the

serpentinites and the granodiorite.

The alteration consist of an halo of proximal silicification chloritisation, epidotisation and potassic

alteration.

The episode of mineralisation occurs during the regional N-S shortening associated with the Variscan

orogeny. It reactivated the ancient and major Eburnean and Pan-African faults. Gold and molybdene

seems to be introduce in the system by hot and deep magmatic fluid. Cobalt, arsenic and nickel are

lixiviated from the serpentinites by exogen fluids. The deposition of mineralisation would occur by

mixing between these 2 fluids at the contact of serpentines and dolomite, or in veins that crosscut the

serpentines.

The district is still running exploration essentially by magnetic susceptibility reduce to pole to highlight

serpentine horizons. They also use bore hole geophysic to detect the high density mineralized zone.

Geochemical exploration consist in ionic leaching and research of tracer elements as Co, As, Ni, Au.


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Figure 7: Visit of Bleida mine. A: Geological map of the Bou Azzer District with localisation of Bou Azzer mine and Bleida

mine. B: Photography of the well 3 with the decantation basin. C: Erytrite mineralisation with carbonate-Co bearing. D: Group photography with the mine geologist Saĩd Ilmen.


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4.7 May 19th: Amensif Mine (Cu-Pb-Zn ± Au-Ag deposit)

Amensif Mine is located in the western High Atlas mountains, at about 85 km southwest of Marrakech

city. Amensif Mine is also located 5 km south of the Azegour Mine, which is property of Maya Gold

Mining. The Mo, W and Cu mineralisation of Azegour is related to the Asgour granitic batholith

(metasomatism). The Amensif operation is owned by Managem, and the visit was organised by Abdelali

Khalifa, Chief Geologist. He gave us a briefing on the mine geology, structures and mineralisation. Then

he showed us several drill cores coming from sterile, altered and mineralised zones. We could also see

the entrance of the mine and its outdoor installations.

The mineralisation is hosted in Early Cambrian dolomites (cipolin). It is overlaid by carbonates and

schists. The mineralisation is mostly polymetallic (Cu, Pb, Zn ± Au-Ag) but can also be monometallic (4

to 5 % Cu). It forms carbonate-replacement lenses (220 m x 5 m) or sulfide veins, the latter being related

to Azegour batholith. Au is found in association with chalcopyrite. Ag can be found with Cu in the

chalcopyrite lattice. Galena sometimes contains Ag.

The deposit is cross-cut by at least 4 faults generations. The most important are the 2 sinistral faults

dislocating the mineralised areas in a horst and graben pattern. Alteration is located up to 10 m around

these faults. The alteration halo is characterised by chlorite, biotite, or garnet (andradite) in skarns.

Though, alteration is not used for exploration as faults have proven to be more reliable.

The mine is currently running an underground exploitation up to 250 m deep. The exploitation is

divided into three zones because of the 2 major sinistral faults, which separates zones with different metal

endowment: 1) the North Zone, which is Cu-rich. Mineralisation is hosted in massive dolomite; 2) the

South Zone (or Central Zone), where the mineralisation can be mono- or polymetallic and hosted in

metamorphosed dolomites (skarn). It is mostly exploited for the Zn (± Ag) contained in sphalerite. This

area is located in a fault zone, and its extension at depth is not defined yet, as the fault offset is not known;

3) the Extreme Zone, where the mineralisation can be polymetallic or massive.


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Figure 8 : Visit of the Amensif deposit . A) Some of Amensif drill cores displayed for our visit ; B) Drill core showing mineralised dolomite; C) Detail of chalcopyrite replacing cipolin (in white) in skarns


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5 ACKNOWLEDGEMENTS

This field trip was a complete success and we are grateful to the companies that provide us the

opportunity to realize this project. We want to thanks the SEG for its financial help and its support.

We want also to address a special thanks to all the geologists of MANAGEM for theses wonderful

moment, for the time, the knowledges they gave to our student. Thanks to Hassan Nabil (Director of

Regional Exploration of MANAGEM) for permit us to visit such beautiful places. We are also thankfully

to Rajae Hammouch who lead and accompanied us in this field trip. And we want to deserve a very

special thanks to Denis Côté who gave his time and was of a great support, without whom this field trip

wouldn’t have been possible.

6 REFERENCES

Ettaki, M. (2003). Etude sédimentologique et stratigraphique du Lias-Dogger de la région de Todhra-

Dadès (versant sud du Haut Atlas centra, Maroc). – Implications géodynamiques, thèse de doctorat,

université Cadi Ayyad, Marrakech. 429 p

Lescuyer, J, L., Lesitel, J, M., Marcoux, E., Milési,J, P. & Thiéblemont, D. (1998). Late Devonian-

Early Carboniferous peak sulfide mineralization in the Western Hercynides. Mineralium Deposita. Vol

33, 208 – 220pp

Levresse, G., Cheilletz, A., Gasquet, D., Reisberg, L., Deloule, E., Marty, B. & Kyser, K. (2004).

Osmium, sulphur, and helium isotopic results fro;m the giant Neoproterozoic epithermal imiter silver

deposit, Morocco : evidence for a mantle source. Chem Geol. 207 (1-2), 59 – 79 pp.

Montenat, C., Monbaron, M., Allain, R., Quesbi, N., Dejax, J., Henandez, J., Russell, D. & Taguet P.

2005. Stratigraphie et paéloenvironnement des dépôts volcano-détritiques à dinausoriens du Jurassique

inférieure de Toundounte (Province de Ouarzazate, Haut-Atlas – Maroc).

Tuduri, J., Chauvet, A., Ennaciri, A. & Barbanson, L. (2005). Model of formation of the Imiter silver

deposit (eastern Anti-Atlas, Morocco). New structural and mineralogical constraints. Geoscience. Vol

338, n°4, 253 -261 pp.

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