Northeastern Calabria Research Articles

Terrace Morpho-Sedimentary Sequences on the Sibari Plain (Calabria, Southern Italy): Implication for Sea Level and Tectonic Controls

The Sibari Plain (northeastern Calabria) shows a well-developed stair of late Quaternary marine/coastal terraces resulting from the interaction between sea level fluctuations and tectonic uplift. This paper (i) provides a stratigraphic description of terraced deposits between the Raganello and Coscile rivers, (ii) assesses the relative controls of eustacy and uplift on the staircase formation, and (iii) unravels the Quaternary morphosedimentary evolution of the study area. A geomorphological approach was coupled with stratigraphic field surveys. Photo interpretation, topographic map analyses, and field surveys allowed us to map ten orders of terraces forming telescopically incised valley-fills. Based on the uppermost position of foreshore deposits on inner margins and an average uplift rate of ~1 mm/y, inferred from the Marine Isotope Stage (MIS) 5.5, terraces were correlated with highstands. Sedimentological and stratigraphic analyses allowed us to recognize four assemblages of genetically associated sedimentary facies related to superimposed and juxtaposed coastal and alluvial systems, showing a seaward-stepping architecture. Based on stratal geometry and facies association, we argue that alluvial/fluvial sediments and coastal depositional systems formed contemporaneously along the same terrace. Terrace arrangement resulted from repeated cycles of valley incision (sea level fall) and aggradational to progradational stacking pattern (sea level rise and highstands) in a framework of sustained uplift.

I Florensi nelle strutture politiche, religiose e socio-economiche della Calabria (XII–XIII sec.)

Abstract A specific area of north-eastern Calabria, between the Sila and the Ionian Sea, profoundly Greek and with a degree of stability from the Byzantine to the Norman era and even beyond, represents an ideal local area in which to document the development of the Florensian monastic organization, with its political, social and religious peculiarities. The interaction of Joachim of Fiore and his monks with the political and ecclesiastical authorities did not differ from those of other monastic institutions in the area. As regards the latter, the Cistercians in particular, despite the criticisms levelled by the abbot of Fiore, exhibited similar practical behaviour, both religious and economic, especially in the struggle for the demanium, and this sometimes led to conflict. Both „new“ orders, however, participated in the transition of the area towards the Latin reform.

Evidence for extended Hercynian basement and a preserved Jurassic basin-margin tract in Northern Calabria (Southern Italy): The Longobucco Basin

In the Longobucco Basin (northeastern Calabria, Southern Italy) a Mesozoic succession covers the Hercynian basement, documenting the evolution of a continental margin during the Early Jurassic extensional tectonic phase correlated with the Western Tethys rift. The basin evolved from continental red beds around the Rhaetian/Hettangian boundary to shallow marine and eventually deep-sea siliciclastic turbidites in the late Pliensbachian/Toarcian, to dominantly pelagic deposits (Middle Jurassic onwards). Around the Sinemurian/Pliensbachian boundary, following a prominent phase of normal faulting, sedimentation took different paths in either hangingwall-block or footwall-block settings. This study, based on geological mapping, focuses on the southwestern boundary of the Longobucco Basin and in particular on the mutual relationships existing between the deeper-water basin-fill units (Fiume Trionto and Fosso Petrone Formations), the basement, and the shallow-water limestone of the Caloveto Formation which forms a narrow strip running parallel to the rift shoulder. The contacts among the above-mentioned units are generally all stratigraphic (unconformities of various types: onlap, downlap, nonconformity). These characteristics separate the study area from the depocentral parts of the basin in terms of vertical stratigraphy, nature of contacts among stratigraphic units (unconformable vs conformable), and impact of synsedimentary tectonics. The signature of Early Jurassic extension occurs in the form of (1) laterally continuous clastic bodies interpreted as products of catastrophic basin margin collapse and avalanching, (2) exhumation of the pre-rift units, which are otherwise deeply buried, and (3) neptunian dykes of at least two generations.Our new data provide evidence for the presence of a 20 km long, NW-SE trending preserved paleoescarpment, where the basinal units onlap either the basement or the Caloveto Formation which forms a fringing carbonate body with intriguing facies and bio-sedimentological features. The paleoescarpment was the submarine morphological expression of a Sinemurian/Pliensbachian fault, as testified by the age of the clastic body that seals it. Another pulse of synsedimentary extension took place in the latest Pliensbachian/Toarcian, overprinting the existing rift architecture and reviving the production of megaclastic deposits.

Stratigraphy, composition and provenance of argillaceous marls from the Calcare di Base Formation, Rossano Basin (northeastern Calabria)

AbstractThe Calcare di Base Formation is a part of the Rossano Basin characterizing the Foreland Basin System of northeastern Calabria. Messinian argillaceous marls from the Calcare di Base Formation have been studied to characterize the sedimentary evolution of this formation during the post-orogenic phases of the Calabria–Peloritani Arc. The mineralogical assemblage of the argillaceous marls is dominated by phyllosilicates (illite, chlorite, illite/smectite mixed layers and traces of kaolinite), carbonate minerals (calcite, aragonite and dolomite), quartz and traces of feldspars (both K-feldspars and plagioclase), gypsum and celestine. The palaeoweathering index records changes at the source, reflecting variations in the tectonic regime as shown in the A–CN–K plot, where the studied samples describe a trend typical of a source area in which active tectonism allows erosion of all zones within weathering profiles developed on source rocks. The studied samples are derived from an environment in which non-steady-state weathering conditions prevailed. This trend could record deformational events that affected the Mediterranean area during the Miocene. The Th/Sc versus Zr/Sc ratios and Al–Zr–Ti plot suggest that the samples likely record a recycling effect from their basement rocks. The geochemical proxies of these samples suggest a provenance from a mainly felsic source. The Messinian argillaceous marls record that deposition probably occurred in a semi-closed marine environment mainly subject to hypersalinity with local episodes of meteoric water influx, during a period characterized by persistent dry and warm/arid conditions alternating with relatively wet conditions.

Landslide inventory map of north-eastern Calabria (South Italy)

Landslides are one of the most widespread natural hazards in many areas of Calabria region (Southern Italy), due to the combination of its peculiar geological, morphological, and climatic characteristics and very often to unsustainable land management. This study reports the reconnaissance and the characterization of landslides of north-eastern Calabria (south Italy). The landslide inventory map was obtained by combining field surveys with the analysis of topographic maps and multi-temporal air photos, taken in the period ranging from 1954 to 2006. This analysis has provided the spatial and temporal evolution of mass movements. The integration and elaboration of the data obtained in a GIS environment provided the inventory map of landslides on a scale 1:50,000. Landslides are widespread in the study area and play an important role in the present-day landscape evolution. A total of 1003 landslides were recognized, occupying a surface of 230.4 km2, about 30.5% of the whole study area. The landslides were mapped on the basis of the movement type, as follows: slides, flows, falls and complex landslides. Slide and complex type mass-movements are very common, and represent more than 87% of the landslides mapped. The pelitic lithologies show the highest density of landslides, mainly complex type. Multi-temporal air photo interpretation and field surveys provided data for distinguishing the state of activity of the landslides; therefore, 29% of the landslides mapped has been assessed active while the remaining 71% has been considered inactive. This kind of map is an useful tool for land planning policy. As all the data are digitized and stored in GIS database, this will provide the basic input needed to generate the landslide susceptibility assessments besides evaluate the landslide hazard and risk.

Arc‐parallel strain in a short rollback‐subduction system: The structural evolution of the Crotone basin (northeastern Calabria, southern Italy)

Calabria, located in southern Italy, is the exposed part of the forearc in the Ionian/Tyrrhenian subduction‐rollback boundary. We present a tectonic model for the evolution of Calabria during the last 12 Ma that incorporates the structure and stratigraphy of the Crotone basin. At the re‐initiation of rollback, we document listric normal faults that accommodated a deep‐rooted extensional regime. Extension ceased in the Tortonian and did not continue throughout rollback. The middle Tortonian to early Messinian is characterized by distal sedimentation despite rapid rollback. Westward verging thrusts in Tortonian sediments and olistrostrome deposits within the Messinian section can be explained by instabilities in the accretionary wedge during the Messinian salinity crisis. Tectonic quiescence returned to the basin after the crisis and continued until a north‐south shortening event in the middle Pliocene. Our kinematic data and new evidence of two basin inversions suggest arc‐parallel shortening of the forearc. We propose that this shortening correlates with the passage of the forearc through the Apulia‐Nubia narrow. This data also dispute previous interpretations of the Crotone basin as a pull‐apart or transtensional basin. The identification of the main structures in the Crotone basin suggest a shift from quiescence to upheaval, beginning with Pliocene arc‐parallel shortening associated with the passage of the forearc through the Apulia‐Nubia narrow and continuing until today.

“Punishment for the Sinner”: Holocene episodic subsidence and steady tectonic motion at ancient Sybaris (Calabria, southern Italy)

Although the Calabria region in southern Italy experienced Quaternary uplift, intense Holocene subsidence is documented at ancient Sybaris, one of the most powerful among the Greek colonies collectively known as Magna Greacia. Sybaris flourished along the Ionian Sea coast of north-eastern Calabria since 2.7 ka BP and until the end of the Roman empire, when it went progressively concealed below the ground. Study of the Latest Pleistocene–Holocene evolution of this area involved analysis of the relative sea-level history for individual borehole logs, based on re-calibration of published ages and stipulation of nominal sea-level positions related to each marker. For investigation of the short-term evolution, a novel compilation of geological and archaeological sea-level markers was supported by new radiometric ages. Appraisal of the position of dated markers, when compared to a sea-level curve built on purpose for this coast using an updated glacio-hydro-isostatic model, indicates a locally intense difference in vertical motion between boreholes located away from, or close to, the ancient town. Specifically, whereas data from the basement of the archaeological layers document large subsidence, more distant sites behaved differently. A site ∼2 km to the NW of the settlement was apparently stable throughout the Holocene, and a site ∼6 km to the SE experienced uplift at ∼1.5 mm/y since 0.6 ka BP. In addition, analysis reveals temporal changes in subsidence pattern in the archaeological area. Large (5–6 mm/y) Early Holocene subsidence at Sybaris slowed to ∼1.5 mm/y during the middle part of the Holocene. The slowing-down trend continued during and after historical occupation at ∼0.8 mm/y, a value similar to the long-term (35–40 ka BP) rate established from the deepest borehole samples. These data are interpreted as suggesting that sediment compaction affected the basement of Sybaris during the Early Holocene, and progressively ceased during historical times, when a tectonic signal prevailed. During historical time, the spatial difference in vertical motion is chiefly attributed to differential growth of nearby folds documented by morpho-tectonic studies on-land and seismic profiles analysis in the offshore of Sybaris. Whereas location above a syncline caused tectonic subsidence at Sybaris, the regions to the north and south record stability or uplift that reflects transition to growing anticlines. In the short term (1–10 ka scale), these local tectonic processes prevail over the regional uplift pattern, which is expressed at the 100 ka scale or over.

Geomorphological Map of the Ionian Area between the Trionto and Colognati River Catchments (Calabria, Italy)

Please click here to download the map associated with this article. This paper describes a geomorphological map representing a sector of the Ionian coastal belt, located in north-eastern Calabria, between the catchments of the Trionto and Colognati Rivers. The landforms have been distinguished according to their origin into: a) structural and tectonic-controlled landforms; b) gravity-induced landforms; c) landforms formed by running water; d) coastal and transitional landforms; e) anthropic landforms, using as support a simplified topographic map on scale 1:20,000. The geomorphological map provides information about the long-term evolution of the landscape and identifies the geomorphic processes presently active. Therefore, the map could be used in developing land management and planning guidelines.

Clay Mineral Assemblages and Sandstone Compositions of the Mesozoic Longobucco Group, Northeastern Calabria: Implications for Burial History and Diagenetic Evolution

Mesozoic mudrocks and sandstones from the Longobucco Group (Sila Unit, North Calabria) were mineralogically, chemically, and petrographically analyzed for their burial, diagenesis, and sourcearea weathering histories. These sediments mark an important phase of the regional geological evolution along internal domains of the circum-Mediterranean chains from the Gibraltar Arc (Spain and Morocco) to the Calabria-Peloritani orogen (Italy). The effects of diagenesis on quartzose sandstone-mudstone lithotypes in the Mesozoic Longobucco Group succession are quantified. The basal Longobucco Group consists of continental clastic redbeds deposited in a rapidly subsiding rift-valley basin, overlain by shallow-marine to deep-marine carbonate and clastic strata. These sediments were analyzed using thin-section petrography, SEM/EDS, X-ray diffraction (XRD), and fluorescence. Quartzarenites display heterogeneous distributions of authigenic quartz, kaolin, illite, feldspar, and minor carbonate cementation. Authigenic zoned syntaxial overgrowths on detrital quartz represent the principal cement, and interstitial clay is an important component of these lithotypes. The mineralogical assemblage of mudrocks is dominated by illite and illite/smectite mixed layers. This observation, coupled with the CIA index and the A-CN-K plot, suggests post-depositional K-enrichment. Paleoweathering indices (CIW and PIA ratios) suggest that the source experienced intense weathering and that mudrocks likely record recycling from metasedimentary basement rocks. Clay-mineral distributions of sandstone/mudstone lithotypes indicate that mixed-layer illite/smectite with ordered interstratification (from R = 1 to R = 3) dominates mudstone mineralogy. Authigenic clays in sandstone are kaolinite, illite, chlorite, and kaolinite illitization as pore filling and lining. These authigenic clays show a distinct distribution, reflecting differences in burial/temperature history. The illite crystallinity index, the illitization of kaolinite, and the occurrence of high-illite I/S mixed-layer clay minerals suggest burial depths of at least 4-6 km and a temperature typical of the boundary between late diagenesis to low anchizone.

Raised coastal terraces along the Ionian Sea coast of northern Calabria, Italy, suggest space and time variability of tectonic uplift rates

A detailed study of uplifted Middle–Late Pleistocene marine terraces on the eastern side of northern Calabria, southern Italy, provides insights into the temporal and spatial scale variability of vertical displacement rates over a time span of ∼400 ka. Calabria is located in the frontal orogen of southern Italy above the westerly-plunging Ionian slab, and a combination of lithospheric, crustal, and surface processes concurred to rapid Late Quaternary uplift. Eleven terrace orders and a raised Holocene beach were mapped up to ∼480 m a.s.l., and were correlated between the coastal slopes of Pollino and Sila mountain ranges across the Sibari Plain, facing the Ionian Sea side of northeastern Calabria. Precise corrections were applied to the measured shoreline angles in order to account for uncertainty in measurement, erosion of marine deposits, recent debris shedding, and bathymetric range of markers. Radiometric (ESR and 14C) dating of shells provides a crono-stratigraphic scheme, although many samples were found to be resedimented in younger terraces. Terrace T4, whose inner margin stands at elevations of 94–130 m, is assigned to MIS 5.5 (∼124 ka), based on new ESR dating and previous amino acid racemization estimations. The underlying terraces T3, T2 and T1 are attributed to MIS 5.3 (∼100 ka), 5.1 (∼80 ka) and 3 (∼60 ka), as inferred from their relative position supplemented by ESR and 14C age determinations. The age of higher terraces is poorly constrained, but conceivably is tracked back to MIS 11 (∼400 ka). The reconstructed depositional sequence of terraces attributed to MIS 5.5 and 7 reveals two regressive marine cycles separated by an alluvial fanglomerate, which, given the steady uplift regime, points to minor sub-orbital sea-level changes during interstadial highstands. Based on the terrace chronology, uplift in the last ∼400 ka occurred at an average rate of 1 mm/a, but was characterized by the alternation of more rapid (up to ∼3.5 mm/a) and slower (down to ∼0.5 mm/a) periods of displacement. Spatial variability in uplift rates is recorded by the deformation profile of terraces parallel to the coast, which document the growth of local fold structures.

Detrital Modes in a Late Miocene Wedge-Top Basin, Northeastern Calabria, Italy: Compositional Record of Wedge-Top Partitioning

Abstract The composition and stratigraphic relations of sandstones and associated conglomerates derived from erosion of the northern Calabrian terranes provide important constraints for paleotectonic and paleogeographic models of the Neogene wedge-top depozone evolution of the southern Italy foreland basin system. After onset of continental collision in the southern Italy orogenic belt during late Oligocene to early Miocene, the Calabrian Arc drifted northeastward, accreting over the Adria lithosphere during mid to late Miocene time. Since the Tortonian, the northern Calabrian terranes represented an uplifted thrust belt in which along its leading edge tectonic subsidence was responsible for accumulation of a thick Tortonian to Quaternary succession, dominantly siliciclastic (up to 3300 meters thick), deposited in the wedge-top depozones (Rossano and Crotone basins). Sandstone assemblages have a homogeneous quartzofeldspathic composition in the Rossano and Crotone basins, characterized by a compositional trend, through time in response to regional tectonics. Evolution of the basins fill occurred during (1) Serravallian?–Tortonian, (2) late Tortonian to early Messinian, and (3) late Messinian. Detritus shed into those basins was derived mainly from terranes within the strongly deformed Sila Mountains allochthon, which was one of the principal structural elements of the nearby northern Calabrian terranes, consisting of Hercynian plutons intruding Paleozoic (Cambrian to Carboniferous) metasedimentary host rocks, and locally having a sedimentary cover of Mesozoic (Longobucco Group) or early Miocene (Paludi unit) clastics. Low- to medium-grade metamorphic and minor plutonic grain types (metamorphiclastic petrofacies) represent the main detritus in the earliest (Serravallian?–Tortonian) sedimentation that accompanied progressive flexural bending of the western margin of the foreland-basin system. Tortonian to early Messinian time was characterized by isolation of the Mediterranean region from the global marine realm, leading to evaporite sedimentation in the foreland in addition to intense regional and local tectonics. Compositional response to those events was a marked increase in sedimentary detritus (sedimenticlastic petrofacies) related to cannibalization of early Messinian evaporite successions; after the evaporitic events within the basins and the gradual re-establishment to the normal marine conditions, sandstone detrital modes are characterized mainly by a return of the Serravallian?–Tortonian compositional modes (i.e., metamorphic–plutoniclastic petrofacies). The post-evaporitic sedimentation corresponds to a major tectonic rearrangement on both Rossano and Crotone basins related to extrusion and inversion of the basal portion of the Serravallian?–Tortonian sequences in the intermediate zone to form an intervening Ciro structural high. In the Crotone Basin during late Messinian, deposition of the Carvane Conglomerate records an abrupt sudden arrival of distinctive sedimentary containing clasts of detritus of reddish limestone, marl, quartz arenite, siltstone and chert derived from Mesozoic to Tertiary basinal sequences of the southern Apennines domains (i.e., Sicilide Complex terranes). Detrital-mode evolution of the inner portions of the late Miocene southern Italy foreland-basin system was in response to abrupt tectonic partitioning due to continuation of accretionary processes, rapid uplift of mid-crustal blocks, and the superposition of wrench tectonics.

DINOFLAGELLATE CYSTS AND CALCAREOUS NANNOFOSSILS FROM THE UPPER CRETACEOUS SARACENO FORMATION (CALABRIA, ITALY): IMPLICATIONS ABOUT THE HISTORY OF THE LIGURIDE COMPLEX

Organic-walled dinoflagellate cysts and calcareous nannofossils recovered from the turbidites of the Saraceno Formation outcropping in the type area (north-eastern Calabria, Italy) are presented. They provide new information about the age of the Saraceno Formation, hence a constraint to reconstruct the timing of deformations that affected the Liguride Complex. The distribution of dinoflagellate cysts and calcareous nannofossils in the succession studied is compared with biostratigraphies available for the Upper Cretaceous. Accordingly, the age of the lowermost part of the Fiumara Saraceno section is latest Albian to Turonian, whereas the upper part of the section is dated as late Campanian-?earliest Maastrichtian. A hiatus spanning che Coniacian, che Santonian and most of che Campanian is inferred between these two successions, which are also distinguished by the presence and absence of flint respectively. Consistencies and discrepancies of che present data with biostratigraphical information previously published for che Saraceno Formation, are discussed.