The geological map of the Majella Mountain

This geological map of the Majella Mountain, at 1:25.000 scale, is the result of research that started in the ‘80s as field-based learning and training in structural analysis and stratigraphy/sedimentology for graduate students on the Regional Geology and Stratigraphy courses, led respectively by Paolo Scandone and Etta Patacca at the University of Pisa. The Majella, one of the most beautiful and sunny mountains of Abruzzo, is (in Paolo Scandone’s words) a real “training ship for geologists”. Its excellent outcrops of lower Cretaceous to Tertiary basinal and shallow-marine carbonates, which enable complete geological investigations (from paleontological and sedimentological /stratigraphic analyses to structural ones) have been studied by several generations of students and researchers from various Italian and international universities and exploration companies, the latter being interested in the local geomineral resources. The scientific interest of the Majella is testified by the many publications in national and international journals and by the numerous geological maps dating back to the early ‘900. While this is not the place to provide an exhaustive bibliography, it is important to mention, as starting points on the development of this map, the pioneering stratigraphic work of CRESCENTI U. et al. (1969), the numerous sedimentological analyses published by BERNOULLI D. and his students, the geologic maps in the works of ACCARIE H. (1988), DONZELLI G. (1969) and VECSEI A. (1991) as well as the sheets n°147 Lanciano and n°153 Agnone at 1:100.000 scale of the SERVIZIO GEOLOGICO D'ITALIA.
This map is the synthesis of the geological surveys carried out at 1:10,000 scale between 1986 and 2007. The cartographic project, coordinated by P.Di Manna, E. Patacca and P. Scandone who have been respectively responsible for the editing, stratigraphic analyses and mapping activity, has seen the contribution of researchers (see list on the map) from research groups of the CNR-"Centro di Studio per il Quaternario e l'Evoluzione Ambientale" and the Universities of Roma-La Sapienza, Roma-Tre, Torino and Pisa. In 2000-2003 the research was supported by ENI-AGIP Exploration and Development Division and, as co-sponsorship, by NorskHydro (now Statoil), within theResearch Project TASK FORCE MAJELLA (coord. J.P. van Dijk Eni E&P Division, San Donato Milanese).
The Majella Mountain is an arc-shaped anticline trending NW-SE in the north and NNE-SSW in the south, made up of Mesozoic-Tertiary carbonates overlain by Messinian evaporites and hemipelagic marls followed by lower Pliocene siliciclastic flysch deposits. In the north, the Majella Unit is tectonically covered with by closely folded Messinian-lower Pliocene siliciclastic flysch deposits belonging to the Queglia Unit, a nappe occupying in the Apenninic edifice an intermediate position between the Majella and the Morrone-Porrara units. The northern termination of Majella beneath the Queglia Unit is a periclinal closure controlled by the gentle plunging of the fold axis towards the NW. The southern termination, controlled by an axial plunging towards SSW, is less regular because of the occurrence of extensional faults which have re-utilized the previous thrust surface of the Morrone-Porrara Unit over Majella. Along the eastern flank of the anticline, which dips regularly towards the east, basin-derived allochthonous sheets (Molise Nappes) tectonically lie over the Pliocene flysch of Majella (see the regional geological-structural scheme on the map). The western margin of Majella coincides with a system of normal faults (Caramanico Fault System) displaying a maximum cumulative downthrow that exceeds 3.500 meters. This fault system has been interpreted as a gravity-collapse feature that has progressively accommodated with a listric geometry the increase in the structural elevation created by a backthrust structure grown in the footwall of the Majella anticline (Patacca et al., 2008). In correspondence to the fold axis culmination, the Majella carbonates are spectacularly exposed in peaks exceeding 2700 meters in elevation.
The paleogeographic evolution of the Majella Mountain from the Early Cretaceous to Pliocene time and the relationships between the recognized lithostratigraphic units, along an ideal N-S transect, are synthesized in the stratigraphic schemes. The detailed cartographic mapping required the introduction of new lithostratigraphic units, mainly in the tertiary time, and the redefinition of the rank of others already known in literature. A substantial amount of data coming from a sequence stratigraphic approach to the facies analysis, strictly controlled by microfacies analysis and matched to micropaleontologic investigations based on both planktic forams and shallow benthic organisms, has allowed a detailed reconstruction of the spatio-temporal relationships between the basinal deposits of the northern part of Majella and the shallow-water carbonates cropping out in the south. The chronostratigraphic scheme documents the evolution over time of the depositional setting of the Majella region which, from a platform-to-basin carbonate system during the greatest part of the Cretaceous gradually evolves, during the Paleogene and Neogene, into a deepening upward carbonate ramp and finally into a foredeep basin. The chronostratigraphic scheme includes the adopted biostratigraphy, with integrated planktic and benthic zonations revised and calibrated to "A Concise Geologic Time Scale 2016" by OGG J.G. et al. 2016see stratigraphic references in the map). This scheme provides a physical stratigraphic framework of the Majella region which highlights and focuses on those key surfaces and chronostratigraphic datum levels that can be correlated with bioevents and physical events recognized at a global scale.

This map is dedicated to Rinalda Di Stefano and Paolo Scandone, who left us prematurely before this map, which is also the result of their passionate and tireless work and knowledge contribution, was printed.

We would like to thank the Abruzzo Region for the funding that enabled the final printing of this map.

REFERENCES

ACCARIE H. (1988) – Dynamique sédimentaire et structurale au passage plate-forme/bassin. Les faciès carbonatés crétacés et tertiaires du Massif de la Maiella (Abruzzes, Italie). Ecole des Mines de Paris, Mémoires de Sciences de la Terre, 5, pp. 1-162.
CRESCENTI U., CROSTELLA A., DONZELLI G. & RAFFI G. (1969) – Stratigrafia della serie calcarea dal Lias al Miocene nella regione marchigiano-abruzzese. (Parte II. Litostratigrafia, Biostratigrafia, Paleogeografia). Memorie della Società Geologica Italiana, 8, pp. 343-420.
DONZELLI G. (1969) - Studio geologico della Maiella. Edited by Crescenti U., 1997. Università degli Studi G. D’Annunzio, Chieti, Italy, pp. 1-49, 21 tavv.
EBERLI G.P., BERNOULLI D., SANDERS D. & VECSEI A. (1993) – From aggradation to progradation: the Maiella platform, Abruzzi, Italy. In SIMO T., SCOTT R.W. & MASSE J.P. (Eds), Cretaceous Carbonate Platforms. Memoirs of the American Association of Petroleum Geologists, 56, pp. 213-232.
PATACCA E., SCANDONE P., DI LUZIO E., CAVINATO G.P. & PAROTTO M. (2008) – Structural architecture of the central Apennines: Interpretation of the CROP 11 seismic profile from the Adriatic coast to the orographic divide. Tectonics, 27: TC3006, doi: 10.1029/2005TC001917.
VECSEI A. (1991) – Aggradation und Progradation eines Karbonatplattform-Randes: Kreide bis Mittleres Tertiär der Montagna della Maiella, Abruzzen. Mitteilungen aus dem Geologischen Institut der Eidgenössischen Technischen Hochschule und der Universität Zürich, Neue Folge, nr. 294.

STRATIGRAPHIC REFERENCES

BLOW W. (1969) - Late-Middle Eocene to Recent planktonic foraminiferal biostratigraphy In BRONNIMANN P. & RENZ M.M. (Eds.) "Proceedings of the First International Conference on Planktonic Microfossils" (Geneve 1967), Leiden, E.J. Broll, 1, pp. 199-421.
BERGGREN W.A. & MILLER K.G. (1988) - Paleogene tropical planktonic foraminiferal biostratigraphy and magnetobiochronology. Micropaleontology, 34, pp. 362-380.
BOLLI H.M. & SAUNDERS J.B. (1985) - Oligocene to Holocene low latitude planktic foraminifera. In: BOLLI H.M., SAUNDERS J.B. & PERCH NIELSEN K. (Eds.), Plankton Stratigraphy, vol.1. Cambridge Earth Science Series, Cambridge Univ. Press, pp. 155-263.
CAHUZAC B. & POIGNANT A. (1997) - Essai de biozonation de l'Oligo-Miocène dans les bassins européens à l'aide des grands foraminifères néritiques. Bull. Soc. géol. France, 168 (2), pp. 155-169.
CHIOCCHINI M, CHIOCCHINI R.A., DIDASKALOU P.& POTETTI M. (2008) - Ricerche micropaleontologiche e biostratigrafiche sul Mesozoico della piattaforma carbonatica laziale-abruzzese (Italia centrale). Mem. Descr. Carta Geol. d'It., LXXXIV (2008), pp. 5-170.
COSENTINO D., BUCHWALDT R., SAMPALMIERI G., IADANZA A., CIPOLLARI P., SCHILDGEN T.F., HINNOV L.A., RAMEZANI J. & BOWRING S.A. (2013) - Refining the Mediterranean ‘‘Messinian gap’’ with high-precision U-Pb zircon geochronology, Central and Northern Italy, Geology, 41, pp. 323–326.
IACCARINO S.M., PREMOLI SILVA I., BIOLZI M., FORESI L.M., LIRER F., TURCO E. & PETRIZZO M.R. (2007) - Practical Manual of Neogene Planktonic Foraminifera. International School on Planktonic Foraminifera. (Neogene Planktonic Foraminifera) - Perugia 19-23 February 2007. pp. 1-180.
OGG J.G., OGG G.M. & GRADSTEIN F.M. (2016) - A Concise Geologic Time Scale: 2016. Elsevier, Cambridge 240 pp.
ROBASZYNSKI F. (1998) - Planktonic foraminifera. Columns for Jurassic chart of Mesozoic and Cenozoic sequence chronostratigraphic framework of European basins, by Hardenbol J., Thierry J., Farley M.B., Jacquin Th., de Graciansky P.-C. & Vail P.R. (coordinators). In: DE GRACIANSKY P.C., HARDENBOL J., JACQUIN Th. & VAIL P.R. (Eds.), Mesozoic-Cenozoic Sequence Stratigraphy of European Basins. SEPM Special Publication, 60, pp. 763-781.
SERRA-KIEL J., HOTTINGER L., CAUS E., DROBNE K., FERRÀNDEZ C., JAUHRI A.K., LESS G., PAVLOVEC R., PIGNATTI J., SAMSÓ J.M., SCHAUB H., SIREL E., STROUGO A., TAMBAREAU Y., TOSQUELLA J. & ZAKREVSKAYA E. (1998) - Larger foraminiferal biostratigraphy of the Tethyan Paleocene and Eocene. Bull. Soc. Géol. France, 169(2), pp. 281-299.
SLITER W.V. (1989) - Biostratigraphic zonation for Cretaceous planktonic foraminifers examined in thin section. Jour. Foram. Res., 19 (1), pp. 1-19.
TOURMAKINE M. & LUTERBACHER H.P. (1985) - Paleocene and Eocene planktic foraminifera. In: BOLLI H.M., SAUNDERS J.B. & PERCH NIELSEN K. (Eds.), Plankton Stratigraphy, vol.1. Cambridge Earth Science Series, Cambridge Univ. Press, pp. 87-154.