Iron mineralisation in Mio-Pliocene sediments of the Tamra iron mine (Nefza mining district, Tunisia): Mixed influence of pedogenesis and hydrothermal alteration

Decrée, Sophie; Putter, Thierry De; Yans, Johan; Moussi, Béchir; Récourt, Philippe; Jamoussi, Fakher; Bruyère, Delphine; Dupuis, Christian

doi:10.1016/j.oregeorev.2007.02.001

Cited by 24 publications

(50 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A late discrete hydrothermal event is observed in several of these deposits, expressed as As-rich galena (Sidi Driss, Jalta) or jordanite (Jb el Hamra, Jalta), resulting from the interaction of galena with an As-rich fluid. Late As-rich sulphide veins are also encountered in the Pliocene Tamra Fe deposit (Decrée et al 2008b), suggesting that this event must be considered Pliocene in age.…”

Section: Paragenesis and Ore Texturementioning

confidence: 97%

“…The Tamra Pliocene basin, unconformably overlying the Sidi Driss basin, is the host for iron mineralization in the form of a 50-m-thick succession of iron hydroxide-bearing sediments (Tamra Formation). Each mineralized sequence results from (1) sedimentation of iron-rich lateritic material, and (2) in situ pedogenetic reworking and iron concentration without evidence of a precursor hydrothermal event (Decrée et al 2008b). A Late Pliocene low-temperature hydrothermal iron mineralization, accompanied by Mn, Sr, Ba, Zn, and Pb, is superimposed on this sedimentary iron concentration (Decrée et al 2010;Moussi et al 2011).…”

Section: Polymetallic Mineralization In the Nefza Mining Districtmentioning

confidence: 99%

“…At Sidi Driss, the ore is stratabound and composed mainly of galena, sphalerite, and late Fe-sulphides (Decrée et al 2008b). It is disseminated or banded (Fig.…”

Section: The Sidi Driss and Douahriamentioning

confidence: 99%

“…However, this zone is better known for containing a large variety of polymetallic deposits, among which several are present in the Nefza district. This district is characterized by the occurrence of late Tertiary mineral deposits, including the Tortonian Oued Belif iron oxide uranium (IOU) showing (Decrée et al 2013), the Messinian Sidi Driss and Douahria Ba-Zn-Pb Sedex deposits (Decrée et al 2008a), and the Pliocene iron deposit of Tamera (Decrée et al 2008b). The two Sedex deposits are attributed to formation by thermally-driven circulating fluids related to Late Miocene magmatism and reactivation of shear zones during Messinian extension.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Tectonomagmatic Context of Sedex Pb–Zn and Polymetallic Ore Deposits of the Nappe Zone Northern Tunisia, and Comparisons with MVT Deposits in the Region

Decrée

Marignac

Abidi

et al. 2016

Mineral Deposits of North Africa

Self Cite

View full text Add to dashboard Cite

The Nefza region (Nappe Zone, northern Tunisia) is known both as a Late Miocene magmatic province and a base-metal district. In this region, small, post-nappe, continental extensional basins (Sidi Driss and (Sedex). In addition to this mineralization, the Nappe zone contains other Pb-Zn and polymetallic deposits that show similarities both to the SHMS-Sedex and MVT deposits of the Dome and Graben zones, namely the "peri-diapiric" deposits of Jebel (Jb) el Hamra, Jalta, and Jebel Ghozlane. All of the Nappe Zone deposits share common characteristics, including: (1) age-the deposits formed between late collisional events (Late Tortonian) and inception of the Early Messinian extensional regime, in the context of the Alpine Maghrebide belt formation; (2) presence of pre-existing sulphates-these were likely the main source of sulphur for the sulphides; and (3) hydrothermal systems leading to their genesisthese testify to alternating influx of cold and warm fluids. The involvement of high temperature fluids are deduced from fluid inclusion studies (Th values of 140-240°C), whereas the presence of distinctive sphalerite textures (microspherules and colloform textures) and sulphur isotopic compositions demonstrate in situ bacterial sulphate reduction, and consequently deposition at temperatures below 80°C. These data constitute unifying characteristics for these mineralizations that are in contrast to the features of Pb-Zn(-fluorite) MVT deposits occurring in the Dome and Graben zones of Tunisia. The geodynamic context prevailing during the Late Miocene in the Nappe Zone is the underlying common factor that explains the diversity of ore deposits formed at that time in this region. Most deposits are located in the vicinity of shear zones and associated lineaments inherited from the Variscan orogeny. These deep structures were reactivated by transtensional processes during the Alpine orogeny and controlled post-collisional magmatism, circulation of hydrothermal fluids, and locations of related ore deposits and showings in the Nappe Zone.

show abstract

Section: Paragenesis and Ore Texturementioning

confidence: 97%

Section: Polymetallic Mineralization In the Nefza Mining Districtmentioning

confidence: 99%

“…At Sidi Driss, the ore is stratabound and composed mainly of galena, sphalerite, and late Fe-sulphides (Decrée et al 2008b). It is disseminated or banded (Fig.…”

Section: The Sidi Driss and Douahriamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Tectonomagmatic Context of Sedex Pb–Zn and Polymetallic Ore Deposits of the Nappe Zone Northern Tunisia, and Comparisons with MVT Deposits in the Region

Decrée

Marignac

Abidi

et al. 2016

Mineral Deposits of North Africa

Self Cite

View full text Add to dashboard Cite

show abstract

“…The Oued El Maadene basin, which belongs to Nefza mining district, has various metal-rich deposits (Fe, Pb, Zn, etc. ;Abidi 2010;Decreé et al 2008). There are two active iron mines (Tamera and Boukhchiba) and several abandoned Pb-Zn mines (Sainfeld 1952).…”

Section: Study Areamentioning

confidence: 99%

Spatial assessment and source identification of trace metal pollution in stream sediments of Oued El Maadene basin, northern Tunisia

Ayari

Agnan

Charef

2016

Environ Monit Assess

View full text Add to dashboard Cite

An extensive spatial survey was conducted on trace metal content in stream sediments from Oued El Maadene basin, northern Tunisia. Our objectives were to evaluate the level of trace metal pollution and associated ecological risk and identify the major sources of metal pollution. A total of 116 stream sediment samples were collected and analysed for total As, Cd, Cr, Cu, Ni, Pb, V, Zn, and Zr concentrations. The results showed that concentrations of Cr, Ni, V, and Zr were close to natural levels. In contrast, As, Cd, Cu, Pb, and Zn had elevated concentrations and enrichment factors compared to other contaminated regions in northern Tunisia. Ecological risk to aquatic ecosystems was highlighted in most areas. Principal component analysis showed that Cr, Ni, V, and Zr mainly derived from local soil and bedrock weathering, whilst As, Cd, Pb, and Zn originated from mining wastes. Trace metals could be dispersed downstream of tailings, possibly due to surface runoff during the short rainy season. Surprisingly, Cu, and to a lesser extent As, originated from agricultural activities, related to application of Cu-based fungicides in former vineyards and orchards. This study showed that, despite the complete cessation of mining activities several decades ago, metal pollution still impacts the local environment. This large pollution, however, did not mask other additional sources, such as local agricultural applications of fungicides.

show abstract

Geologic and Metallogenic Framework of North Africa

Bouabdellah

Slack

2016

Mineral Deposits of North Africa

View full text Add to dashboard Cite

North Africa is noteworthy for having a great diversity of geology and mineral resources. Geologically, the region contains numerous terranes that contain rocks ranging in age from Archean to Quaternary, including diverse igneous, sedimentary, and metamorphic lithologies. Major geological features were built during the main phases of Proterozoic and subsequent Phanerozoic orogenies, the break-up of the supercontinents Rodinia, Gondwana, and Pangea, and during the opening and closing of major ocean basins such as the Iapatus, Atlantic, Pacific, and Tethys. Three major tectono-stratigraphic domains are recognized (1) the Precambrian province that includes the African-Nubian Shield (ANS) to the east and the West African Craton (WAC) to the west, and the intervening Tuareg Shield and "Saharan Metacraton"; (2) the Variscan (Paleozoic) fold belt; and (3) the Atlas-Alpine (Mesozoic-Cenozoic) system. Mineral deposits of North Africa formed in a variety of geologic settings at different time periods from Archean to Quaternary. Mineral commodities including gold, silver, cobalt, nickel, chromium, arsenic, copper, lead, zinc, iron, and many other elements. Major deposit types present in the region are (1) orthomagmatic Cr-Ni-platinum group elements (PGE); (2) rare-metal granites and related rare-element pegmatites; (3) volcanic-hosted massive sulphide (VHMS); (4) sedimentaryexhalative (SEDEX); (5) orogenic and intrusion-related gold; (6) iron oxide-copper-gold (IOCG); (7) banded iron formation (BIF); (8) Mississippi Valley-type (MVT) lead-zinc; (9) sediment-hosted stratiform copper;Electronic supplementary material The online version of this chapter

show abstract

Iron mineralisation in Mio-Pliocene sediments of the Tamra iron mine (Nefza mining district, Tunisia): Mixed influence of pedogenesis and hydrothermal alteration

Cited by 24 publications

References 6 publications

Tectonomagmatic Context of Sedex Pb–Zn and Polymetallic Ore Deposits of the Nappe Zone Northern Tunisia, and Comparisons with MVT Deposits in the Region

Tectonomagmatic Context of Sedex Pb–Zn and Polymetallic Ore Deposits of the Nappe Zone Northern Tunisia, and Comparisons with MVT Deposits in the Region

Spatial assessment and source identification of trace metal pollution in stream sediments of Oued El Maadene basin, northern Tunisia

Geologic and Metallogenic Framework of North Africa

Contact Info

Product

Resources

About