Volume N° 4 - from P14 to P36 32nd INTERNATIONAL GEOLOGICAL CONGRESS PLIO-PLEISTOCENE STRATIGRAPHIC AND TECTONIC EVOLUTION OF THE FORELAND-FOREDEEP-CHAIN SYSTEM IN SOUTHERN ITALY Leaders: P. Pieri, L. Sabato, M. Tropeano Associate Leaders: S. Gallicchio, F. Loiacono, M. Schiattarella Field Trip Guide Book - P35 Field Trip Florence - Italy August 20-28, 2004 Post-Congress P35 P35_ copertina_R_OK C 21-06-2004, 9:43:19 The scientific content of this guide is under the total responsibility of the Authors Published by: APAT – Italian Agency for the Environmental Protection and Technical Services - Via Vitaliano Brancati, 48 - 00144 Roma - Italy Series Editors: Luca Guerrieri, Irene Rischia and Leonello Serva (APAT, Roma) English Desk-copy Editors: Paul Mazza (Università di Firenze), Jessica Ann Thonn (Università di Firenze), Nathalie Marléne Adams (Università di Firenze), Miriam Friedman (Università di Firenze), Kate Eadie (Freelance indipendent professional) Field Trip Committee: Leonello Serva (APAT, Roma), Alessandro Michetti (Università dell’Insubria, Como), Giulio Pavia (Università di Torino), Raffaele Pignone (Servizio Geologico Regione Emilia-Romagna, Bologna) and Riccardo Polino (CNR, Torino) Acknowledgments: The 32nd IGC Organizing Committee is grateful to Roberto Pompili and Elisa Brustia (APAT, Roma) for their collaboration in editing. Graphic project: Full snc - Firenze Layout and press: Lito Terrazzi srl - Firenze P35_ copertina_R_OK D 9-06-2004, 10:15:47 Volume n° 4 - from P14 to P36 32nd INTERNATIONAL GEOLOGICAL CONGRESS PLIO-PLEISTOCENE STRATIGRAPHIC AND TECTONIC EVOLUTION OF THE FORELAND- FOREDEEP-CHAIN SYSTEM IN SOUTHERN ITALY AUTHORS: P. Pieri¹, L. Sabato¹, M. Tropeano², A. Albianelli3, A. Bertini3, V. Festa1, S. Gallicchio¹, F. Loiacono¹, C. Lombardi3, F. Masini3, M. Moretti1, G. Napoleone1, L. Pomar4, M. Schiattarella², L. Spalluto1 1Università di Bari - Italy 2Università della Basilicata, Potenza - Italy 3Università di Firenze - Italy 4Universitat de les Illes Balears Florence - Italy August 20-28, 2004 Post-Congress P35 P35_R_OK A 9-06-2004, 10:41:52 Front Cover: Nonna Carmela. Albano di Lucania (southern Apennines, Basilicata). P35_R_OK B 9-06-2004, 10:41:54 PLIO-PLEISTOCENE STRATIGRAPHIC AND TECTONIC EVOLUTION OF THE FORELAND-FOREDEEP-CHAIN SYSTEM IN SOUTHERN ITALY P35 Leaders: P. Pieri, L. Sabato, M. Tropeano Associate Leaders: S. Gallicchio, F. Loiacono, M. Schiattarella 1. Introduction Oligo-Miocene deposits are today tectonized and P. Pieri, L. Sabato, M. Tropeano added in the accretionary wedge. Younger (Plio-Pleis- The aim of this fi eld trip is to illustrate the three main tocene) foredeep deposits are less deformed and, in depositional areas of the Plio-Pleistocene Apennines southern Italy, they are well exposed as a consequence foredeep system (foreland, foredeep s.s., and satellite of a severe Quaternary uplift which affected and af- basins) in southern Italy and to discuss its evolution fects the whole south-Apennines orogenic system showing stratigraphic and sedimentologic features of (chain, foredeep and foreland settings). This allows tectonized to practically undeformed Plio-Pleistocene us to observe, during our fi eld trip, stratigraphic, sedi- successions. mentologic, and tectonic features of Plio-Pleistocene The Apennines foredeep (Italy) is the Upper Oli- successions of the whole south-Apennines foredeep gocene to present-day foreland basin developed on system. the fl exured Adria Plate. Up to Pliocene time, the The fi eld trip will develop between Apulia (evening Apennines foredeep was a deep basin characterized of day 1) and Basilicata (days 2 to 5) regions (back cover and Figs. 7, 9, 28) and crosses a complete geological section of the Plio-Pleistocene foredeep system (Figure 2), beginning from the outer foreland ramp (Apulian Foreland - late evening of day 1 and day 2) as far as the younger thrusts of the Apennines (inner foredeep sector - day 3), through the foredeep s.s. (Bradanic Trough) (day 4) and the coeval satellite Sant’Arcangelo Basin (day 5) (Figure 3). As regards fi eld map references, we will refer to some geological maps of the Italian Geological Survey (Servizio Geologico d’Italia, sheets n°: 176 “Barletta”; 188 “Gravina”; 189 “Altamura”; 200 “Tricarico”; 201 “Matera”; 211 “Sant’Arcangelo”), and to other geological maps (“Carta Tettonica d’Italia” by Funiciello et al., 1975; “Carta geologica dell’Appennino meridionale” by Bonardi et al., 1988a; “Carta geologica delle Murge e del Salento” by Ciaranfi et al., 1988). As regards road map references, we will refer to the “Grande carta stradale d’Italia 1: 200.000” made by the TCI (Touring Club Italiano – sheets: “Campania e Basilicata”, and “Puglia”). Figure 1 - Schematic structural map of Italy showing the 2. Regional geological setting present-day location of the Apennines foredeep. P. Pieri, L. Sabato, M. Tropeano The growth of the Apennines chain (Italy) started mainly by turbidite sedimentation (Pescatore, 1978; during Late Oligocene times (Boccaletti et al., 1990), P14 to P36 olume n° 4 - from Ricci Lucchi, 1986; Casnedi, 1988; 1991; Ori et al., when the Adria Plate, characterized by both oceanic 1991), while the Quaternary Apennines foredeep is a (Ionian sector) and continental (Apulia sector) litho- V basin characterized by: i) a subsiding overfi lled sector sphere (Finetti, 1982; Catalano et al., 2001), began (Po Plain); ii) a subsiding nearly fi lled sector (north- to subduct back to the Alpine-Betic thrust belt; the central Adriatic Sea); iii) an uplifted, exposed, and Alpine-Betic back-thrust belt and the hinterland of cannibalized sector (Bradanic Trough); iv) a deep- the same Alpine-Betic orogen (the undeformed Adria) marine basin only in the southernmost part of the were progressively involved in this westward subduc- present-day foredeep (the Taranto Gulf in the Ionian tion (Doglioni et al., 1998, and references therein). Sea) (Tropeano et al., 2002a, and references therein) The Apennines foredeep (Figure 1) is the foreland (Figure 1). basin related to the Apennines thrust belt; its subsid- 3 - P35 P35_R_OK 3 9-06-2004, 10:42:24 Leaders: P. Pieri, L. Sabato, M. Tropeano P35 Figure 2 - Geological cross-section showing the main nines, to the north of the Maiella Mountain and the structural elements of the south-Apennines orogenic Tremiti line, thrusts propagation mostly proceeded by system (modifi ed from Sella et al., 1988). imbricate fans development in piggyback sequences, ence rate is higher than 1 km/Myr (Doglioni, 1994) which progressively involved the foreland (Bally et and is induced by the eastward roll-back of the Adria al., 1986). In the southern Apennines, thrusts propa- Plate (slab pull and sinking, and/or opposition to rela- gation mostly proceeded by long sheets (the “alloch- tive eastward mantel fl ow) rather than by thrust-sheet thon”) which overthrust the south-Apennines foreland loading (Royden et al., 1987; Doglioni, 1991, and ref- (the Apulian Foreland). Only after its underthrusting erences therein). The Apennines foredeep depocent- did thrusts propagate in the foreland (Mostardini and ers moved towards the E-NE (Ricci Lucchi, 1986; Merlini, 1986) and a large-scale duplex system form Boccaletti et al., 1990) following the fast Apennines (Patacca and Scandone, 2001, and references therein) arc migration, which has been calculated to be in the (Figs. 2, 4). order of 700 km in southern Italy (i.e. Calabrian arc) Therefore, two different styles of foredeep migration (Patacca et al., 1990; Gueguen et al., 1997); this value characterize the central and southern Apennines. In linearly decreases moving towards the northern Apen- the central Apennines, the foreland sedimentary cover nines and, accordingly, both the amount and velocity is directly involved in the thrust propagation and is of crustal shortening decrease from about 5-6 cm/yr predominantly added to the front of the accretionary to less than 1 cm/yr moving from south to north along wedge (Argnani et al., 1991); in contrast, in the south- the Apennines (Patacca and Scandone, 1989). The ern Apennines (from the Abruzzi-Molise southward structural and sedimentary history of the Apennines up to the Basilicata region), foreland sedimentary foredeep records this progressive eastward migration cover is underthrust by the “allochthon” (Ciaranfi of the orogenic system. Thrusting propagated within et al., 1979) (Figs 2, 4, 5b). Moreover, the Apulian the foredeep, splitting it into an internal shallower Foreland has been uplifting since Early-Middle basin (a piggyback area or a wedge-top basin) and an Pleistocene times (Ciaranfi et al., 1983). According external deeper one (foredeep s.s.); high subsidence to Doglioni et al. (1994) this uplift is related to the rates gradually involved more eastern sectors of the arrival of a thicker lithosphere in the south-Adriatic foreland (Ricci Lucchi, 1986; Boccaletti et al., 1990; subduction hinge, which lowered subduction rates olume n° 4 - from P14 to P36 olume n° 4 - from Ori et al., 1991; DeCelles and Giles, 1996) (Figure and caused the slab to buckle; northward and south- 4). Moreover, the progressive eastward migration ward of Apulia the Apennines foreland continues to V of the orogenic system induces the superposition of subside (Doglioni et al., 1996). tensional and/or transtensional tectonic regimes back In consequence of both uplift of the foreland and to the active piggyback area over chain sectors previ- propagation of the duplex system in the south-Apen- ously characterized by compressional regimes