GEOMORPHOLOGICAL MAP OF TREMITI ISLANDS (PUGLIA, SOUTHERN ADRIATIC SEA, ITALY) Ud A udi sità degli St “G. d’Annu Scale 1:15.000 niver nzio” U Enrico Miccadei,Tommaso Piacentini, Francesco Mascioli Universita’ degli Studi “G. d’Annunzio” Chieti-Pescara Laboratory of Tectonic geomorphology and GIS - INGEO Dipartimento di Ingegneria e Geologia [email protected] - [email protected]

INTRODUCTION STUDY AREA The Tremiti Islands lie in the central-southern Adriatic Sea, in northern Apulia, at about 20 km north from Gargano promontory coast. It includes San Domino, San Nicola, Capraia and Cretaccio islands, and La Vecchia rock; Pianosa island, also belonging to the archipelago, is 11 miles away from the main ones towards NE. Being located around the centre of the Adriatic basin, and facing the junction between central and southern Apennines, the islands lie in a complex geological area, crucial for the study of Quaternary Adriatic basin evolution, strongly driven by eustatic processes and tectonics along well known regional faults. The archipelago is the emerged part of one of the main structural highs within the Adriatic basin, well studied for erosional/depositional processes on the continental shelf due to Late Quaternary tectonics and eustatic sea-level changes. A detailed integrative geomorphological analysis in the Tremiti Islands, on both the islands and the inner continental shelf around the islands, enabled the elaboration of a geomorphological map (1:15,000 scale) of above and below sea level areas. The Geomorphological map of the Tremiti Islands (Puglia, Southern Adriatic Sea, Italy), scale 1:15,000, incorporates three main sections: 1) main geomorphological map and legend (center and left on the Map); 2) geomorphological profiles and morphostratigraphic correlation of Quaternary continental deposits (lower part of the Map); 3) geomorphological block diagrams and figures (right on the Map); The study characterizes deposits and erosion surfaces of the Quaternary continental succession, outlining some new chronological constraints; main tectonic and geomorphological features, in surface and underwater area, are defined. The geomorphological and stratigraphical data analysis allowed the reconstruction of morphostratigraphic relationships between the islands; moreover, the correlation with tectonic features allowed the recostruction of morphotectonic setting of the archipelago. At local scale, this correlation has provided a contribution to the reconstruction of Late Quaternary landscape and geomorphological evolution, as the result of tectonics, sea-level fluctuations and marine, coastal, and continental geomorphological processes. At a regional scale, this study provides new data useful for the reconstruction of foreland area Quaternary evolution, due to the relationships between tectonic and eustatic processes, as well as clues and contributions for the correlation to coastal and piedmont areas. Discussion and conclusion coming from this analysis has been presented in two specific research paper on international journals.

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Tremiti Capraia UNIVERSITA’ DEGLI STUDI “G. d’Annunzio” Chieti-Pescara Islands -55 Rome -60 INGEO Dipartimento di Ingegneria e Geologia -54 A' This work is based on a detailed geomorphological analysis of the Tremiti Central Adriatic Pelagosa Ridge Z Z Z Z CB B -30 Laboratory of Tectonic geomorphology and GIS Z Z B Z B B Z 120 Pianosa I. Z

-8 B Islands and of the inner continental shelf sea bottom around them, from Z B D 100 San Nicola B B Br Tremiti I. Z D 80 Cretaccio Z -5 Geomorphological map of Tremiti Islands D D Faro di Z B B Punta Secca 40 4663300 4665800 Capraia B coastline to about 70 m b.s.l., incorporating: (1) field mapping of Quaternary B B 11.0 Cala del 41.6 (Puglia, Southern Adriatic Sea, Italy) 20 Caffè Termoli B 17.5 San Domino Z B 4650000 4700000 Capraia continental deposits and landforms, supported by U/Th and OSL dating, Bathimetry 100 ES Scale 1:15.000 Side scan sonar survey -35

Gargano Z B Main Quaternary Diving survery sites 29.5 CB fault systems NE SW 24.5 (2) bathymetric analysis, (3) side scan sonar survey and (4) scuba-dive Mattinata Fault 0 10 km 0 1000 m Miccadei E.1 , Orrù P.2, Piacentini T.1, Mascioli F.1 , Puliga G2 . Structural highs 20 Quaternary continental deposits and tectonical features. a) San Domino, Cala degli Inglesi, stratified breccia (Br), formed Coordinate system UTM 33N-WGS84 Coordinate system UTM 33N-WGS84 Cala of decimetrical and centimetrical clasts, in lightly cemented red-brown sandy matrix, laying on an erosive surface, within 500000 550000 600000 538500 541000 543500 dei Turchi pre-existent depressed morphologies, on Cenozoic carbonate bedrock (CB). In the higher part outcrops calcretes (Cr), about geomorphological mapping. 0.7-0.8 m thick. b) San Domino, Poggio Romito, visible E-W fault plain on carbonate bedrock. NW SE b 1 Universita’ degli Studi “G. d’Annunzio” Chieti-Pescara B 2.6 INGEO Dipartimento di Ingegneria e Geologia c 12.3 a b The field mapping study was carried out by means of a geological survey Laboratory of Tectonic geomorphology and GIS -5 8.2 [email protected]

[email protected] B 22.3 -10 Cr 2 of Quaternary continental deposits (1:5,000 scale), allowing for the Università degli Studi di Cagliari DISTER Dipartimento di Scienze della Terra B N c Journal of Maps, 2012 Gli Scoglietti 40.4

Cala B construction of detailed lithostratigraphic logs for each island, and

QUATERNARY SUCCESSION Sorrentino B B B

Marine areas B geomorphological survey (1: 5,000 scale, and 1:1,000 for the most significant Z 16.4 Gravel (Gr) -28 -24 areas). Dating of a calcrete and an aeolian deposit supported the Punta dello

-30 Straccione CB Sand (Sn) -23 Z Punta del morpholithostratigraphic correlation of the deposits among the different Cimitero Silt (Sl) 50 24.7 islands. B B Continental areas 70.7 Geomorphological features. a) San Domino, karst pothole in the north-east sector of the island, with calcretes on top (Cr);

B B dashed line indicates a tectonic discontinuity, characterized by NW-SE fault planes and cataclastic rocks. b) San Domino Eluvium-colluviam,soils (S) island, submerged cave at 10 m b.s.l. Bathymetric analysis has been performed processing and interpolating

B Holocene Punta del B

Diamante 50.1 B B B a b

Aeolian sands (As) -11 -4 B data from nautical cartography of Istituto Idrografico Militare, Piano Nautico B B

Upper Pleistocene B 76.2 31.2 B

-11 Cretaccio B n. 204 ‘Isole Tremiti e Pianosa’ (1:15,000 scale). The resulting map has Calcretes (Cr) 1.5 Cala Tamariello B San Nicola -24 Upper Pleistocene -5 24.8 B

Scoglio B B 56.0 12.7 la Vecchia a detail that enables the analysis of the main morphological features and

Breccia, paleosoils, conglomerates, red loess B 70.2 B

(Br,Ps,Cg,Ls,Br1,Ps1,Cg1) B a B

30.2 12.2 B 65.9

Middle Pleistocene B B 18.7 B B to discriminate flat areas and scarps.

-15 B 22.1

B B

B B B i Pagliai B B B

CARBONATE BEDROCK 21.6 19.3 B 58.2 B B B 3.1 1.5 Bathymetric data allowed for plan geomorphological survey of an area of

Dolomites, dolomitic limestone, Cala della 16.8 B B calcarenitic limestone and marls (CB) Tramontana

B 39.7 -20 Paleogene-Pliocene -25 B 31.2 about 9 km2, carried out by means of a side scan sonar records (1:5,000

B 33.3 B TECTONICS 40.1 19.7 Punta Vuccolo scale), during the years of 2006 and 2007.

B 30.3 B

Strata attitude B -5 Geomorphological features. a) Capraia island, inner margin of flat surface obbved by bathymetrical analysis, at about 20 30.5 2.8 B m b.s.l. b) Metric sub-rounded coastal rockpools, at 8 m b.s.l. -10 Scuba-dive geomorphological mapping, up to a depth of 50 m b.s.l., allowed Fault -4 Cala degli Inglesi 50 31.8 Buried fault a a for detailed direct observation of inner continental shelf landforms (1:1,000 Inferred fault scale) and the observation of the below sea-level cliff portion and caves, 16.7 6.8 4.7 34.7 GEOMORPHOLOGICAL FEATURES 51.2 enabling side scan sonar record calibration and improvement. Slope gravity landforms San Domino 6.7 Cala Matano Landslide deposits Grotta delle 46.8 Rondinelle 55.4 43.7 -49 Paleolandslide deposits

14.0 Punta 0.7 49.0

Fluvial landforms Secca B -18 l'Architiello

Fluvial paleoincision 51.7 B 0.4 Morpho-lithostratigraphic scheme of the Quaternary continental deposits -62 B -25

80.1 B B 97.6

Karst landforms B

B B Scoglio 19.6 dell'Elefante Cave 112.7 San Domino. Block diagram of "I Pagliai" active cliff, in the north-eastern sector of island. Lithology: CB- Carbonate

27.5 bedrock (Paleocene-Pliocene); Cr-Calcrete (Upper Pleistocene); Gr-Gravelly and sandy deposits (Holocene). Tectonics: B Grotta F-Fault with visible plan; ct-Cataclastic rocks; J-Joints. Landscape: a-Rockfall landslides deposits; b-Detritic fans; c- Submerged cave del Sale Grotta del Caves; d-Dolines; e-Active cliff; f-Shore platform; g-Rocks and stacks; h-Rockpools. Bue Marino B Karst depression and doline B 27.4 B -70 B B b B B 58.9 -50 Marine landforms 32.4

-5 B -65

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B Cliff edge -64 -40 25 delle Viole Z Cliff foot 4.5

Z A Shoreplatform Punta di -20 Zio Cesare

Underwater isolated rock

Emerged rocks and stack

Rockpool -45

Alluvial fan

Marine erosion surface 8 m b.s.l. 0 1000 m Capraia. Block diagram of northern sector. Lithology: CB-Carbonate bedrock (Paleocene-Pliocene); Br,Ps,Cg-Breccia, paleosoils, conglomerates, red loess (Middle-Upper Pleistocene); Sl-Silty deposits (Holocene). Tectonics: F-Fault. Landscape: a-Landslide deposits; b-Landslide surface; c-Caves; d-Dolines; e-Active cliff; f-Marine erosion surfaces; g- Marine erosion surface 20 m b.s.l. Coordinate system UTM 33N-WGS84 Shelf seaweeds. Topographic data courtesy of Cartographic Office Regione Puglia (http://www.sit.puglia.it/) c Marine erosion surface 55 m b.s.l. Bathymetric contourlines interpolated from Piano Nautico n. 204 "Isole Tremiti e Pianosa" - Istituto Idrografico Militare

Features connected to biological activity Posidonia oceanica QUATERNARY SUCCESSION A A' Marine areas [ [ Erosion surface ES4 Continental shelf seaweed SW NE WSW ESE SW NE (Holocene) Gravel San Domino Erosion surface ES3 Dating Continental areas 100 100 (Upper Pleistocene) Eluvium-colluvium,soils (S) U/Th Holocene Erosion surface ES2 OSL Aeolian sands (As) Capraia Upper Pleistocene (Final Middle Pleistocene) Calcretes (Cr) Cretaccio Upper Pleistocene Erosion surface ES1 Other symbols (Middle Pleistocene) Coastline Breccia, paleosoils, conglomerates, sea level 0 red loess (Br,Ps,Cg,Ls,Br1,Ps1,Cg1) 0 Karst depression Middle Pleistocene Block diagram of area between San Domino and Capraia islands. Lithology: CB-Carbonate bedrock (Paleocene-Pliocene); Submerged photograph location and doline Br1,Ps1,Cg1-Conglomerates and paleosoils (Late Middle Pleistocene); Sn-Sandy deposits (Holocene); Sl-Silty deposits CARBONATE BEDROCK (Holocene); ES-Erosive surface. Tectonics: F-Faults. Landscape: a-Landslide deposits; b-Karst dissolution landforms, Dolomites, dolomitic limestone, m m dolines and minor depressions (Eocene-Upper Pleistocene); c-Karst littoral submerged caves (Eocene-Upper Pleistocene); Block diagram point of view Fault d-Marine surface at 8 m b.s.l. (Holocene); e-Marine surface at 25 m b.s.l. (Upper Pleistocene); f-Marine surface at 50- calcarenitic limestone and marls (CB) 0 1000 m Paleogene-Pliocene 55 m b.s.l. (Holocene); g-Incisions (Upper Pleistocene-Holocene); h-Paleodrainage (Late Middle Pleistocene). da: Miccadei E., Orrù P., Piacentini T., Mascioli F. & Puliga G. (2012) - "Geomorphological map of the Tremiti Islands (Puglia, Southern Adriatic Sea, Italy), scale 1:15,000". Journal of Maps, vol.8, pp.74-87, 2012. http://www.tandfonline.com/doi/abs/10.1080/17445647.2012.668765 QUATERNARY CONTINENTAL DEPOSITS MAIN TECTONIC ELEMENTS GEOMORPHOLOGICAL FEATURES SUBMERGED LANDFORMS

Geomorphological features on the islands (the abbreviations refer to the Morpho- lithostratigraphic scheme included in the map). (a) Capraia, partially submerged karst pothole, along the southern coast of the island; (b) San Domino, karst pothole in the north-east sector of the island, with calcretes on top; dashed line indicates a tectonic discontinuity, characterized by NW-SE fault planes and cataclastic rocks; (c) San Domino, pothole at Cala delle Roselle, partially filled by aeolian sands (AS); (d) San Domino, karst cave at sea-level.

Submerged landforms surveyed by scuba-dive observations on the inner continental shelf (numbers indicates depth); (a) Capraia island, incisions and erosional features, Quaternary continental deposits (the abbreviations refer to the Morpho-lithostratigraphic Main tectonic elements (the abbreviations refer to the Morpho-lithostratigraphic between sea-level and about 20 m b.s.l.; (b) San Domino island, detritic fan with scheme included in the map). (a) San Domino, Cala degli Inglesi, stratified breccia, scheme included in the map). (a) San Domino, I Pagliai, intensely tectonic area, centimetric and decimetric calcareous elements, sub-rounded, fossilized by algal formed of decimetric and centimetric clasts, in lightly cemented red-brown sandy characterized by NW-SE-oriented fault surfaces and cataclastic rocks; (b) Capraia, fouling. Fan apex is located at about 8 m b.s.l.; the toe lies on the flat marine erosion matrix, laying on an erosion surface, within pre-existent depressed morphologies, NW-SE-oriented faults; (c) Cretaccio, NE-SW-oriented faults, characterized by surface at 20 m b.s.l.; (c) San Domino island, cave at sea-level extending down to on Cenozoic carbonate bedrock. In the higher part calcrete outcrops are about 0.7- cataclastic rocks; (d) San Domino, Poggio Romito, visible E-W fault plain on carbonate 8 m b.s.l.; (d) San Domino island, submerged cave at 10 m b.s.l.; (e) Capraia island, 0.8 m thick; (b) San Domino, Cala delle Roselle, stratified breccia with sub-angular bedrock; (e) San Domino, Cala Tramontana, sigmoid structure indicating right strike- flat surface developed between 20 and 25 m b.s.l.; (f) Capraia island, inner margin centimetric clasts, laying on carbonate bedrock; (c) San Domino, Cala delle Roselle, slip kinematic (plan view); (f) San Nicola, tectonic contact between Miocene limestone of flat marine erosion surface observed by bathymetric analysis, at about 20 m b.s.l.; yellow aeolian sand within a karst depression, with a particular of the fossiliferous and marl, in the southeast sector of San Nicola. (g) Capraia island, shore platform at 8 m b.s.l.; (h) Metric sub-rounded coastal content formed of continental gastropods; (d) Capraia, Cala dei Turchi, paleosols rockpools, at 8 m b.s.l. and calcretes, in contact with carbonate bedrock; (e) San Nicola, breccia, paleosols and conglomerates, stratified in about 0.25 m thick layers; in the lower left a close up of the deposits is included; (f) Cretaccio, calcrete in angular discordance on carbonate bedrock, age is 121 ±21 kyr (U/Th dating). CONCLUSIONS The Geomorphological map of the Tremiti Islands, scale 1:15,000, is the result of the integrative geomorphological analysis presented in this work, on both the islands and the inner continental shelf around them. This analysis has provided several elements for the comprehension of the Quaternary continental deposits and geomorphological features, and of the Pleistocene landscape evolution of the archipelago. Quaternary continental deposits and geomorphological features are summarized in the morpho-litostratigraphic scheme, in the geomorphological REFERENCES Ferranti L., Antonioli F., Mauz B., Amorosi A., Dai Pra G., Mastronuzzi G., Monaco C., Orrù P., Pappalardo profile and in the block diagrams included in the map (lower and lower-right section). M., Radtke U., Renda P, Romano P., Sansò P., Verrubbi V., (2006), Markers of the last interglacial sea- The interpretation of new stratigraphical, geomorphological, chronological data, compared with previous studies in the surrounding areas, indicates a correlation (from islands to inner level high stand along the coast of Italy: Tectonic implications. Quaternary International 145-146, 30-54. continental shelf) of subaerial erosion surfaces (ES1, ES2, ES3, ES4) and paleo sea-levels with sea level change curve, allowing for an integration of the limited information existing in this ISPRA Istituto Superiore per la Protezione e la Ricerca Ambientale, (2009b), Progetto CARG: linee guida per il rilevamento geologico, la cartografia e l'informatizzazione dei dati delle aree marine - Scala area. The main subaerial erosion surfaces, following the oldest one on carbonate bedrock (ES1), are ascribed to late Middle Pleistocene (ES2), Upper Pleistocene (ES3) and Upper Pleistocene- 1:50.000. Quaderni Serie III del Servizio Geologico d’Italia 12 II, Roma. Holocene (ES4). Subaerial erosional processes are evident also in the continental shelf areas, where erosion surfaces bound the transgressive/regressive depositional sequences of the Miccadei E., Mascioli F. Piacentini T. (2011a), Quaternary geomorphological evolution of the Tremiti Quaternary marine succession; these surfaces are strongly controlled by eustatic sea-level changes and are refereable to subaerial exposure of platform during final Middle Pleistocene Islands (Puglia, Italy). Quaternary International 232, 3-15. and Upper Pleistocene sea-level lowstands and Holocene rise. Miccadei E., Mascioli F., Orrù P., Piacentini T., Puliga G., (2011b), Late Quaternary paleolandscape GMS Furthermore, the correlation between landform distribution, Quaternary deposits, tectonic features, and eustatic interpretation of morphogenetic processes, provides a new contribution of submerged inner continental shelf areas of Tremiti islands archipelago (northern Puglia). Geografia B G Fisica Dinamica Quaternaria, 34 (2). A IS concerning regional tectonics. The SE-NW paleodrainage networks developed during Late Middle Pleistocene (ES2) and Late Upper Pleistocene (ES4) lowstands were followed by tectonic L Selli R., (1971), Isole Tremiti e Pianosa. In: Cremonini, G., Elmi, C., Selli, R. (Ed.), Note illustrative della

activity during the Middle and Upper Pleistocene, along E-W and SW-NE regional discontinuities. These features have lowered the area between Tremiti and Gargano, beheading the SE- Carta Geologica d’Italia alla scala 1:100.000 Foglio 156 “S. Marco in Lamis”, 49-65. Servizio Geologico

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S a d’Italia, Roma.

I NW Middle Pleistocene fluvial drainage and inducing a strong evolution of the landscape.

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