The Elba Island: an Intriguing Geological Puzzle in the Northern Tyrrhenian Sea 85° Congresso Nazionale Della Società Geologica Italiana, Pisa 6-8 Settembre 2010
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Geological Field Trips Società Geologica Italiana 2013 Vol. 5 (2.1) ISPRA Istituto Superiore per la Protezione e la Ricerca Ambientale SERVIZIO GEOLOGICO D’ITALIA Organo Cartografico dello Stato (legge N°68 del 2-2-1960) Dipartimento Difesa del Suolo ISSN: 2038-4947 The Elba Island: an intriguing geological puzzle in the Northern Tyrrhenian Sea 85° Congresso Nazionale della Società Geologica Italiana, Pisa 6-8 settembre 2010 DOI: 10.3301/GFT.2013.03 The Elba Island: an intriguing geological puzzle in the Northern Tyrrhenian Sea E. Pandeli - G. Principi - V. Bortolotti - M. Benvenuti - M. Fazzuoli - A. Dini - F. Fanucci - F. Menna - G. Nirta GFT - Geological Field Trips geological fieldtrips2013-5(2.1) Periodico semestrale del Servizio Geologico d'Italia - ISPRA e della Società Geologica Italiana Geol.F.Trips, Vol.5 No.2.1 (2013), 114 pp., 61 figs. (DOI 10.3301/GFT.2013.03) The Elba Island: an intriguig geological puzzle in the Northern Tyrrhenian Sea 85° Congresso Nazionale della Società Geologica Italiana, Pisa 6-8 settembre 2010 Enrico Pandeli*,**, Gianfranco Principi*,**, Valerio Bortolotti*, Marco Benvenuti*, Milvio Fazzuoli*, Andrea Dini***, Franco Fanucci****, Francesco Menna*, Giuseppe Nirta* * Earth Sciences Department, University of Florence – Via G.La Pira, 4 – 50121 Florence (Italy) ** IGG-CNR, Section of Florence – Via G.La Pira, 4 – 50121 Florence (Italy) ***I GG-CNR, CNR Pisa Research Area - Via G. Moruzzi, 1 - 56124 Pisa (Italy) ***** Geosciences Department, University of Trieste - Via Weiss, 2 - 34127 Trieste (Italy) Corresponding Author e-mail address: [email protected] Responsible Director Claudio Campobasso (ISPRA-Roma) Editorial Board Editor in Chief Gloria Ciarapica (SGI-Perugia) M. Balini, G. Barrocu, C. Bartolini, 2 Editorial Responsible D. Bernoulli, F. Calamita, B. Capaccioni, Maria Letizia Pampaloni (ISPRA-Roma) W. Cavazza, F.L. Chiocci, R. Compagnoni, D. Cosentino, Technical Editor S. Critelli, G.V. Dal Piaz, C. D'Ambrogi, Mauro Roma (ISPRA-Roma) P. Di Stefano, C. Doglioni, E. Erba, publishing group R. Fantoni, P. Gianolla, L. Guerrieri, Editorial Manager Maria Luisa Vatovec (ISPRA-Roma) M. Mellini, S. Milli, M. Pantaloni, V. Pascucci, L. Passeri, A. Peccerillo, Convention Responsible L. Pomar, P. Ronchi (Eni), Anna Rosa Scalise (ISPRA-Roma) B.C. Schreiber, L. Simone, I. Spalla, Alessandro Zuccari (SGI-Roma) L.H. Tanner, C. Venturini, G. Zuffa. ISSN: 2038-4947 [online] http://www.isprambiente.gov.it/it/pubblicazioni/periodici-tecnici/geological-field-trips The Geological Survey of Italy, the Società Geologica Italiana and the Editorial group are not responsible for the ideas, opinions and contents of the guides published; the Authors of each paper are responsible for the ideas, opinions and contents published. Il Servizio Geologico d’Italia, la Società Geologica Italiana e il Gruppo editoriale non sono responsabili delle opinioni espresse e delle affermazioni pubblicate nella guida; l’Autore/i è/sono il/i solo/i responsabile/i. DOI: 10.3301/GFT.2013.03 The Elba Island: an intriguing geological puzzle in the Northern Tyrrhenian Sea E. Pandeli - G. Principi - V. Bortolotti - M. Benvenuti - M. Fazzuoli - A. Dini - F. Fanucci - F. Menna - G. Nirta INDEX geological fieldtrips2013-5(2.1) Information Tectonic evolution of Elba Island ...............................39 Accretionary stage .......................................................39 Recommendations ......................................................5 Pre-intrusion extensional stage ......................................39 Riassunto ...................................................................6 Syn- and post-intrusion stage ........................................41 Abstract ....................................................................11 Excursion notes Itinerary Introduction .............................................................15 Eastern Elba Island ...................................................44 The tectonic unit of the Elba Island .................................17 Stop 1. The tectonic units of the Spiagge Nere area ...........45 The model of Trevisan ...................................................17 Stop 2. Fe-ores of the Terranea area ..............................48 The new model ............................................................20 Stop 3. The tectonic stack of the Ortano Valley (Ortano, Porto Azzurro unit “AU” (Complex I) ..............................20 Acquadolce, Monticiano-Roccastrada, Tuscan Nappe, Ortano unit “UO” (Complex II pp.) ................................21 Gràssera units) ...........................................................49 Acquadolce unit “AU” (Complex II pp.) ...........................21 Stop 4. The calcshist bodies and the skarn of Torre di Rio .......54 Monticiano-Roccastrada unit “MU” (Complex III pp.) ........22 Stop 5. The Rio Marina mining area ...............................55 3 Tuscan Nappe “TN” (Complex III pp.) ............................22 The Tuscan Nappe South of Cavo ..............................57 Gràssera unit “GU” (Complex III pp.) ............................22 Stop 6. The Tuscan nappe succession .............................58 Ophiolitic unit “OU” (Complex IV) ..................................23 The Tuscan epimetamorphic succession of Capo Eocene flysch unit “EU” (Complex V pp.) ........................24 Castello ....................................................................61 Cretaceous flysch unit “CU” (Complex V pp.) ..................24 Stop 7. The Tuscan epimetamorphic succession, Cala Mio-Pliocene magmatism in the Northern Apennines dell’Alga .....................................................................61 and in the tuscan Archipelago ...................................26 The Gràssera and ophiolitic units .............................63 Tuscan Province Magmatic Rocks ....................................26 Stop 8. The Gràssera unit ..............................................63 Elba Island ..................................................................27 Stop 9. The Gorgoli anticline ..........................................64 Petrogenesis of the Elba Island granitoids ........................30 Stop 10. The thrust contact Tuscan Nappe-Gràssera unit ....65 Ore deposits of Southern Tuscany and Elba Island: an Stop 11. The ophicalcites ..............................................66 index overview ...................................................................32 Stop 12. The base of the Nisportino formation ..................66 The Fe deposits of Elba Island ........................................34 Stop 13. The Nisportino formation ..................................67 The geological features of the marine area around the Stop 14. Pillow lavas .....................................................69 Elba Island ................................................................37 Stop 15. San Felo ophiolitic succession ............................69 DOI: 10.3301/GFT.2013.03 The Elba Island: an intriguing geological puzzle in the Northern Tyrrhenian Sea E. Pandeli - G. Principi - V. Bortolotti - M. Benvenuti - M. Fazzuoli - A. Dini - F. Fanucci - F. Menna - G. Nirta geological fieldtrips2013-5(2.1) Stop 16. Fosso Acquaviva, serpentinites ..........................71 Stop 17. Monte Castello-Cima del Monte Pass. The folded structure of the Volterraio subunit and the shoshonitic dyke ..72 Western and Celtral Elba ...........................................75 Stop 18. View on the Western Elba and the Cretaceous flysch unit of the Central Elba .........................................76 Stop 19. The rocks of the inner part of the M.Capanne contact metamorphic aureole ........................................77 Stop 20. The “eurite” quarry (S. Rocco or Cava di Caolino) ....80 Stop 21. The Monte Capanne monzogranite ....................81 The ophiolitic units of western Elba ...........................89 Stop 22. The ophiolitic rocks of Punta Nera area ................90 4 The ophiolitic units of Pomonte-Fetovaia area ...........93 Stop 23. The metamorphic metasediments of the Ogliera Bridge area .................................................................93 Stop 24. The Tertiary flysch unit of the Fetovaia area .......95 Stop 25. The Tertiary flysch unit of the Central Elba .........96 Stop 26. The low-angle tectonic contact (Colle Reciso detachment fault) between the Ophiolitic unit and the underlying Tertiary flysch unit .......................................97 Stop 27. The sheeted dyke complex of the Ophiolitic unit at Colle Reciso .................................................................98 The Monte Calamita promontory and its iron ores ....98 index Stop 28. The Calamita mine: Northern sector .................103 Stop 29. The Punta Calamita mine: Southern sector ........104 References ..............................................................106 DOI: 10.3301/GFT.2013.03 The Elba Island: an intriguing geological puzzle in the Northern Tyrrhenian Sea E. Pandeli - G. Principi - V. Bortolotti - M. Benvenuti - M. Fazzuoli - A. Dini - F. Fanucci - F. Menna - G. Nirta Recommendations geological fieldtrips2013-5(2.1) Addresses for permissions and information - Parco Minerario dell’Isola d’Elba, Palazzo del Buro, via Magenta 26, 57038 Rio Marina - Elba Island (LI), Italy. Tel. 0039 0565 962088; e-mail [email protected], open from April to October, in the Winter only with previous booking. - Parco Nazionale Arcipelago Toscano, Enfola 5 (Portoferraio) Elba Island (LI), Italy Tel. 0039 0565 919411; Fax 0039