Geology and Metallogenesis of the Sediment-Hosted Cu-Ag Deposit of Tizert (Igherm Inlier, Anti-Atlas Copperbelt, Morocco)

Abstract

The Tizert Cu-Ag deposit is the largest of a series of sediment-hosted copper deposits of the Anti-Atlas copper province in Morocco. Mineralized rocks in the deposit contain disseminated sulphides within a Late Ediacaran, dominantly siliciclastic sedimentary formation named the Basal Series. Isopach map of the Basal Series thickness shows that during the Late Ediacaran the area was composed of large subsiding zones separated by paleohighs. The ore-grade zones are well developed along basin margins adjacent to the basement paleohighs. These mineralized zones display a lateral sulphide zoning with central bornite-chalcocite zones grading outward to intermediate chalcopyrite and external pyrite zones. There is also a vertical sulphide zoning with evolution from bornite and chalcocite dominant mineralized rocks at the bottom to chalcopyrite and pyrite dominant mineralized rocks at the top of the lithostratigraphic succession. A second style of mineralization is represented by sulphide filled fractures and veins present in the Basal Series, as well as in the basement and the overlying dolomites. The similarity of the paragenetic sequences between the disseminated and the vein-hosted mineralization suggests that they may be related to the same mineralizing event, the disseminated style of mineralization being rapidly followed by the onset of the vein-style mineralization.

Formation of the giant Aynak copper deposit, Afghanistan: evidence from mineralogy, lithogeochemistry and sulphur isotopes

“…However, stratigraphical zonation in sulphide mineralogy is clearly evident in the Aynak deposits ( Figure 4) comprising a central bornite-rich zone grading outward to chalcopyrite-rich and external pyrite-pyrrhotite zones. This zonation is typical of sedimenthosted copper deposits, as seen for example in the Ruby Creek (Bornite) Cu-(Co) deposit in Alaska (Bernstein and Cox 1986;Hitzman et al 1986) and the Tizert Cu-Ag deposit in Morocco (Oummouch et al 2017) (Figure 1 (a)). A possible explanation for this zonation is the replacement (within the ore zone) of early-formed framboidal pyrite by Cu-Fe sulphides.…”

Characterization of Weathering Processes of the Giant Copper Deposit of Tizert (Igherm Inlier, Anti-Atlas, Morocco)

“…In this context, exploration of new supergene targets has been carried out in many countries, including Morocco, during the last decade. The Tizert site (western Anti-Atlas, Morocco) is considered as the largest copper deposit in the western Anti-Atlas [4]. This deposit was discovered in 1969.…”

“…Using several mining galleries, the site was first studied between 1970 and 1975 by the Bureau des Recherches Pétrolières et Minières (BRPM), which estimated the reserves to be 1,062,000 t with 2.3% Cu and 65 g/t Ag [5]. Since 2011, exploration studies have been carried out by the Managem group; the resources are now estimated to be 56,820,000 t with 1.03% Cu and 23 g/t Ag [4]. Other copper deposits are currently mined in this part of the Anti-Atlas, especially in Neoproterozoic to Early Cambrian rocks: the Tazalaght mine (reserves of 260,000 t with 1.89% Cu) [5,6], the Ouansimi mine (reserves of 1,087,000 t with 2.63% Cu) [7,8] and the Agoujgal mine (reserves of 5,000,000 t with 1% Cu and 20 g/t Ag) [6,9].…”

“…In their pioneering characterization of the Tizert deposit, the authors in reference [4] mainly (i) highlight mineralogical phases observed in this area, focusing on primary (hypogene) mineral phases; (ii) evaluate its potential for possible exploitation (grades and tonnage). In this study, we complete the primary mineralization data proposed by the authors in reference [4], by characterizing the supergene mineral assemblages in order to determine their formation processes and identify possible enrichment associated to weathering in the Tizert giant Cu deposit.…”

Corrigendum to “Geology and Metallogenesis of the Sediment-Hosted Cu-Ag Deposit of Tizert (Igherm Inlier, Anti-Atlas Copperbelt, Morocco)”

“…In the article titled "Geology and Metallogenesis of the Sediment-Hosted Cu-Ag Deposit of Tizert (Igherm Inlier, Anti-Atlas Copperbelt, Morocco)" [1], the following changes have been applied in place:…”