Database name: |
World Fe-oxide+/-Cu-Au-U (IOCG) deposits |
Compilers: |
Sunil S. Gandhi |
Release date: |
2015-03-04 |
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Deposit name(s): |
Rio Marina |
Political location(s): |
Italy; Province or state: Tuscany; Subprovince or locality: Elba Island; Nearest community: Rome (201 km 302°) |
Deposit clan (type): |
Iron Skarn-type |
Deposit (sub) types: |
stratabound and massive mineralization affected by faulting and fracturing during regional extensional stage; magnetite-rich ore grades upward to specularite-rich ore; limonite-rich capping ; Reference: Duenkel, I.; Kuhlemann, J.; Nohlen, U., 2003: Iron Ore Formation and Neotectonic Evolution in Elba (Tuscany, Italy) during Messinian Plutonism; Neues Jahrbuch fur Geologie und Palaontologie. Abhandlungen, Volume 230, p. 391 - 407 |
Deposit status: |
past producer; Size category: unknown |
Geologic province: |
Alpine Orogen |
Geologic subprovince: |
Apennines |
Geologic district: |
Northern Apennines |
Deposit object located: |
centre-deposit on surface |
Commodities: |
Fe |
Mineralization styles: |
stratiform magnetite layers and lenses; irregular bodies; veins and fracture-fillings; massive magnetite pods in skarn |
Geological ages: |
Late Miocene (mineralization) |
Tectonic setting: |
continental unstated-unqualified; extensional; Formal name: Late Miocene extension and related plutonism (related igneous rocks) |
Coincident features: |
stratification in host sequence (carbonate strata of the host formation, thickened due to isoclinal folding, provide lithological control for mineralization); Coincident feature name: Complex III of Elba Island brecciation along a stratigraphic horizon (clasts of iron ore in breccia and lack of mineralization channels leading to them indicate pre-brecciation origin of mineralization); Coincident feature name: Complex III of Elba Island |
Regional tectonic structure: |
shallow-dipping extensional slides of Late Miocene age with eastward transport (Capo Calamita, Terra Nera, Rio Marina and Rio Albano deposits transported with detachments) Tectonic structure name: Extensional Allochthons |
Host rocks: |
(1) sedimentary; carbonate (Early Permian calcareous rocks of Verrucano Formation overlying Carboniferous shale (graphitic)); Depositional setting: carbonate platform; Metamorphic grade: greenschistExternal host rock forms: | cavernous limestone | Host rock protoliths: | limestone (Rhaetean cellular limestone unconformably overlies clastic Permian beds of Verrucano Formation); Host rock protolith name: Calcare Cavernoso Formation | Internal host rock structures: | fine grained | Individual lithologies: | limestone (defomed, faulted, fractured and altered by contact metasomatism at the deposit) | Host rock stratigraphy: | Complex III of Elba Island |
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Related igneous rocks: |
(1) intrusive; granodiorite-tonalite-diorite suite (deposit genetically related to the intrusion); Initials: Monte Capanne granodioritic pluton; Magma series: calc-alkaline; Depositional setting: continentalIndividual lithologies: | granodiorite (Late Miocene pluton in the western part of Elba Island, related to the poorly exposed Porto Azzurro quartz monzonite to the east) |
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Metallogenic signatures: |
Fe |
Alteration signatures: |
oxidation and supergene enrichment: limonite; What was altered: iron oxides and pyrite potassic alteration: adularia; What was altered: feldspar/clay |
Mineralogy: |
(alteration): limonite, adularia (mineralization): magnetite, pyrite, specularite |
Radiometric ages: |
Object dated: Mineralogy(3); Age - Ma: 5.39; +0.5; -0.5; Dating method: (U-Pb)-4He; Concentrate: specularite; Source rock: ore zone; Formal name: specularite-pyrite phase; Event dated: mineralization (late stage); Interpretive comment: age concordant with the K-Ar age on associated adularia of 5.32 ± 0.1 Ma; Reference: Lippolt, H. J.; Wernicke, R. S.; Bähr, R., 1995: Paragenetic Specularite and Adularia (Elba, Italy): Concordant (U+Th)-He and K-Ar Ages; Earth and Planetary Science Letters, Volume 132, p. 43 - 51
Object dated: Mineralogy(5); Age - Ma: 5.32; +0.1; -0.1; Dating method: K-Ar; Concentrate: alkali feldspar; Source rock: ore zone; Formal name: adularia; Event dated: mineralization (late stage); Interpretive comment: age concordant with the (U+Th)-4He age on associated adularia of 5.39 ± 0.5 Ma; Reference: Lippolt, H. J.; Wernicke, R. S.; Bähr, R., 1995: Paragenetic Specularite and Adularia (Elba, Italy): Concordant (U+Th)-He and K-Ar Ages; Earth and Planetary Science Letters, Volume 132, p. 43 - 51 |
Deposit shape: |
zone of lensoid and irregular bodies |
Qualified comments: |
(Applies to: mineralization) One of the old Elba mines exploited since 2500 years ago; Rio Marina has magnetite-pyrite ore with specularite-limonite cap; total ore production in Elba estimated at 50 Mt and resources of some 26 Mt. |
References: |
Deschamps, Y.; Gagallier, G.; Macaudiere, J.; Marignac, C.; Moine, B.; Saupè, F., 1983 |
Le Gisement de PyriteHematite de Valle Giove (Rio Marina, Ile dElba, Italie) - 1: Contribution à la Connaissance des Gisement de Toscane |
Schwezerische Mineralogische und Petrographische Mitteillungen, Volume 63, p. 301 - 327 |
Duenkel, I.; Kuhlemann, J.; Nohlen, U., 2003 |
Iron Ore Formation and Neotectonic Evolution in Elba (Tuscany, Italy) during Messinian Plutonism |
Neues Jahrbuch fur Geologie und Palaontologie. Abhandlungen, Volume 230, p. 391 - 407 |
Zitzmann, A., 1977 |
The Iron Deposits of Italy |
in The Iron Ore Deposits of Europe and Adjacent Areas: Explanatory Notes to the International Map of the Iron Ore Deposits of Europe, 1:2,500,000 (Text and Figures), Edited by Walther, H. W.; Zitzmann, A., International Geological Congress, Commission for the Geological Map of the World, Subcommission for the Metallogenic Map of the World, Bundesanstalt fur Geowissenschaften und Rohstoffe, Postfach 51 01 53, D-3000 Hannover 51, Volume I, 418 p, p. 209 - 218 |
Zitzmann, A. Editor(s)), 1978 |
The Iron Ore Deposits of Europe and Adjacent Areas: Explanatory Notes to the International Map of the Iron Ore Deposits of Europe, 1:2,500,000 (Lists and Tables) |
International Geological Congress, Commission for the Geological Map of the World, Subcommission for the Metallogenic Map of the World, Bundesanstalt fur Geowissenschaften und Rohstoffe, Postfach 51 01 53, D-3000 Hannover 51, Volume II, 386 p. |
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