http://www.cnr.it/ontology/cnr/individuo/prodotto/ID29003

Sericitic alteration at the La Crocetta deposit (Elba island, Italy): interplay between magmatism, tectonics and hydrothermal activity. (Articolo in rivista)

Type

Prodotto della ricerca (Classe)
Articolo in rivista (Classe)

Label

Sericitic alteration at the La Crocetta deposit (Elba island, Italy): interplay between magmatism, tectonics and hydrothermal activity. (Articolo in rivista) (literal)

Anno

2003-01-01T00:00:00+01:00 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#doi

10.1007/s00126-002-0279-2 (literal)

Alternative label

MAINERI C. (1); BENVENUTI M. (1); COSTAGLIOLA P. (1); DINI A. (2); LATTANZI P. (3); RUGGIERI G. (2); VILLA I.M. (4) (2003)
Sericitic alteration at the La Crocetta deposit (Elba island, Italy): interplay between magmatism, tectonics and hydrothermal activity.
in Mineralium deposita; Springer-Verlag, Berlin Heidelberg (Germania)
(literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori

MAINERI C. (1); BENVENUTI M. (1); COSTAGLIOLA P. (1); DINI A. (2); LATTANZI P. (3); RUGGIERI G. (2); VILLA I.M. (4) (literal)

Pagina inizio

67 (literal)

Pagina fine

86 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#altreInformazioni

Industrial rocks and minerals are currently the main focus of mining industry in Italy. In the specific case, the mining of raw materials for the ceramic industry is of great interest for our country since the Italian ceramic industry is a major economic asset. However, there isn't much, though, about geology, mineralogy and geochemistry of industrial mineral deposits in the international literature. This paper represents a first efforts of providing a scientific background to an important sector of the Italian mining industry by using a multidisciplinary approach. Mineralium Deposita is one of the most quoted journal that published papers on geology, mineralogy and geochemistry of mineral deposits. In particular, this journal introduces new observations, principles, and interpretations from the field of economic geology, including nonmetallic mineral deposits, experimental and applied geochemistry, with emphasis on mineral deposits. (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#url

http://www.springerlink.com/content/mj6tnw9q1bq52tly/ (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume

38 (literal)

Rivista

Mineralium deposita (Rivista)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#note

Impact Factor 1,969 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#pagineTotali

20 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#descrizioneSinteticaDelProdotto

Italy is Europe's largest producer of feldspathic raw materials for ceramic industries, with about 1.8 Mt/year of mined ore. A significant part (average 600,000 t/year) of this production comes from southern Tuscany. The two main deposits are La Crocetta (Elba Island) and Botro ai Marmi (near Campiglia Marittima). In both localities, the quarried rocks are altered magmatic rocks of the Miocene-Pleistocene Tuscan Magmatic Province. Their peculiar potassium-rich (7 to 11 wt% K2O) and Fe-Ca-S-poor compositions make them of high commercial quality. It is, therefore, of interest to study the hydrothermal processes that have produced these unique alteration features. This paper focuses on the La Crocetta deposit, with the ultimate goal of developing a descriptive and genetic model, which may be useful in the exploration for similar products in other hydrothermal systems. The main implication for exploration from the newly proposed model is that any orebody similar to La Crocetta in the Elba Island should be preferentially sought in the upper plate (hanging wall) of the Elba Centrale fault detachment system. It is unlikely that the portions of Capo Bianco porphyritic aplite bodies localized in the lower plate (footwall) of Elba Centrale fault were affected by potassium metasomatism, as a consequence of either their deep emplacement and/or the comparatively limited infiltration of meteoric fluids into rocks of the lower plate. (literal)

Note

Scopu (literal)
ISI Web of Science (WOS) (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni

(1) Dip. Scienze della Terra, Università Firenze, Via G. La Pira, 4, Firenze; (2) Istituto di Geoscienze e Georisorse - CNR, Pisa, Italy (3) Dip. Scienze Terra, Università di Cagliari, Italy (4) Mineral. and Petrographisches Inst., Universität Bern, Switzerland (literal)

Titolo

Sericitic alteration at the La Crocetta deposit (Elba island, Italy): interplay between magmatism, tectonics and hydrothermal activity. (literal)

Abstract

The La Crocetta mine near Porto Azzurro (Elba Island, Tuscany, Italy) is an important producer of raw material for the ceramic industry. Exploitation focuses on a pervasively sericitized porphyritic aplite of the Tuscan Magmatic Province, locally known as ''eu- rite'', which underwent significant potassium enrichment during sericitic alteration. Eurites are located along the hanging wall of the Elba Centrale Fault, a low-angle extensional lineament of regional significance. A later carbonatization stage, apparently associated with high- angle extensional tectonics, locally overprinted the sericitized facies. It is expressed by carbonate ± pyrite ± quartz veins, with adverse effects on ore quality. Sericitization was accompanied by addition of potassium, and loss of Na (± Ca, Fe). Rubidium was not en- riched along with potassium during sericitization, contrary to what would be expected for interaction with late-magmatic fluids. New 40Ar-39Ar data from eurites provide an isochron age of about 6.7 Ma for the sericitization, whereas the age of the unaltered protolith is ca. 8.8 Ma. Field evidence indicates the Elba Centrale Fault to be the main channel for the hydrothermal fluids. On the other hand, the involvement of heat and/or fluids contributed by the Porto Azzurro pluton, which crops out in the La Crocetta area, is ruled out by field, geo- chemical and geochronological data (40Ar-39Ar age of Porto Azzurro =5.9 Ma, i.e. significantly younger than the sericitization event). Fluid inclusion studies suggest that sericitization was associated with a low-temperature (<250 °C) hydrothermal system. Fluids were locally boiling, of variable salinity (4-17 wt% NaCl equiv.), and contained some CO2 (XCO2 £ 0.027). Their ulti- mate source is not unequivocally constrained; meteoric and/or magmatic contributions may be possible. Low- salinity (<= 2.6 wt% NaCl equiv.), low-temperature (<250 °C) fluids are associated with the late carbonate veining. They are considered to be of dominantly meteoric nature because of their low salinity. In summary, sericitization at La Crocetta is regarded as the product of a detachment fault-related, low temperature hydro- thermal system, resulting from the structurally controlled focusing of meteoric and possibly magmatic fluids. Hence, potential targets for exploration for similar resources are represented by aplitic bodies located in the hanging wall of Elba Centrale Fault. (literal)

Editore