An example of a three-type interference pattern in the Tuscan Nappe, South-western sector of Apuan Alps (Northern Apennines, Italy)

The study area is located in the Northern Apennines, which is composed of oceanic and continental- derived tectonic units, stacked toward NE during Apennine subduction (Oligocene to present). The continental-derived units, representative of the Adria paleomargin involved into the collisional phases of the Alpine orogeny, are, from the lower to the upper structural levels: the Apuan Alps Unit, the Massa Unit and the Tuscan Nappe. The Apuan Alps Unit consists of pre-Mesozoic metamorphic basement and metasedimentary cover rocks, ranging from Triassic to Oligocene, deformed and metamorphosed under greenschists facies conditions. The Massa Unit, is also characterized by pre-Mesozoic metamorphic basement unconformably covered by Middle to Upper Triassic metasedimentary rocks. It recorded higher metamorphic conditions respect to underlying Unit. The Tuscan Nappe, instead, is detached from its basement and it is composed by Late Triassic to Early Miocene nonmetamorphic sedimentary rocks. This Unit was deformed at shallow structural levels. In the southeastern sector of the Apuan Alps, sedimentary rocks of the Tuscan nappe crop out. Particularly, in the study area, this unit includes only LateTriassic - Early Cretaceous rocks (Carosi et al., 2005). Field observations and structural data allowed us to elaborate a 1:5.000 scale structural map. Structural analyses highlighted a comlplex deformation history, composed by five deformation events (from D1 to D5), documented a different scale. The D1 event is testified by S1 foliation classifiable as slaty cleavage. In thin section, S1 is emphasised by preferential orientation of phyllosilicates and lenticular domains composed of quartz, calcite, detrital micas, albite and oxides. Open to isoclinal similar folds (F2) with NW-SE trending axes are associated to the D2 event. F2 folds are associated to a well developed S2 axial plane classifiable as crenulation cleavage without significant re-crystallisation. The D3 event is not well developed in this area and it is locally recorded in the fine-grained rocks where it produced isoclinal folds with scattered axes and axial planes oriented N-S. The previous architecture is reworked by folds with chévron geometry and sub-horizontal axial plane associated to the D4 event. Finally, D5 event is characterized by open folds with sub-vertical axial plane and three systems of normal to transtensive faults. These brittle structures, could be interpreted as conjugate faults of the Monte Croce-Pescaglia faults system. In conclusion, field observations and structural analysis conducted both at the micro and at the mesoscopic scale, indicate that Tuscan Nappe exposed in the study area was affected by a kmscale three-type interference pattern (Ramsay, 1967). Furthermore, our studies suggest that the faults played a role of great importance in the present architecture of this sector of the belt

The coupling of high-pressure oceanic and continental units in Alpine Corsica: Evidence for syn-exhumation tectonic erosion at the roof of the plate interface

The subduction of continental crust is now a matter of fact but which are the mechanisms and the factors control- ling the exhumation of continental units and their coupling with oceanic units are still a matter of debate. We herein present the tectono-metamorphic study of selected continental units belonging to the Alpine Corsica (Corte area, Central Corsica, France). The tectonic pile in the study area features thin slices of oceanic units (i.e. Schistes Lustrés Complex) tectonically stacked between the continental units (i.e. the Lower Units), which record a pressure–temperature-deformation (P-T-d) evolution related to their burial, down to P-T-peak conditions in the blueschist facies and subsequent exhumation during the Late Cretaceous – Early Oligocene time span. The metamorphic conditions were calculated crossing the results of three different thermobarometers based on the HP-LT metapelites. The continental units only recorded the P-peak conditions of 1.2 GPa-250 °C, up to the T-peak conditions of 0.8 GPa-400 °C, and the retrograde path up to LP-LT conditions. The metamorphic record of the oceanic units includes part of the prograde path occurring before the peak conditions reached at 1.0 GPa-250 °C followed by the last metamorphic event related to LP-LT conditions. The results indicate that each unit experienced a multistage independent pressure–temperature-deformation (P-T-d) evolution and sug- gest that the oceanic and continental units were coupled during the rising of the last ones at about 10 km of depth, where the oceanic units were stored at the base of the wedge. Subsequently they were deformed together by the last ductile deformation event during exhumation. We propose a mechanism of tectonic erosion at the base of the wedge, by which slices of Schistes Lustrés Complex were removed at the roof of the plate interface during the exhumation of the Lower Units

Trace Elements in Soil and Urban Groundwater in an Area Impacted by Metallurgical Activity: Health Risk Assessment in the Historical Barga Municipality (Tuscany, Italy)

Trace elements were measured in soil and groundwater collected within the Fornaci di Barga urban area (Serchio River Valley, Tuscany, Italy), a territory that integrates natural assets with touristic vocation, impacted by long-lasting metallurgical activity. Epidemiological studies highlighted that the area surrounding the industrial plants is characterized by a persistent excess of diseases, attributed to heavy metal pollution. Soils were taken in school gardens, public parks, sport grounds and roadsides. The results indicate that Cu, Zn and Cd represent the main contaminants in surface soil, likely originated by deposition of airborne particulate matter from metallurgical activity. Risk assessment considering soil ingestion and dermal contact exposure routes revealed that the cadmium Hazard Quotient approaches unity for children, and the cadmium risk-based concentration obtained by combining exposure information with toxicity data is only slightly lower compared with the cadmium maximum concentration actually measured in soil. Groundwater does not show evidence of trace metal contamination, suggesting that the migration of contaminants from soil to subsurface is a slow process. However, assessment of the possible interconnections between shallow and deep-seated aquifers requires monitoring to be continued. The obtained results highlight the possible link between space clusters of diseases and metal concentration in soil

The Cotoncello Shear Zone (Elba Island, Italy): The deep root of a fossil oceanic detachment fault in the Ligurian ophiolites

The ophiolite sequences in the western Elba Island are classically interpreted as a well-exposed ocean-floor section emplaced during the Apennines orogeny at the top of the tectonic nappe-stack. Stratigraphic, petrological and geochemical features indicate that these ophiolite sequences are remnants of slow-ultraslow spreading oceanic lithosphere analogous to the present-day Mid-Atlantic Ridge and Southwest Indian Ridge. Within the oceanward section of Tethyan lithosphere exposed in the Elba Island,we investigated for the first time a 10s of meters-thick structure, the Cotoncello Shear Zone (CSZ), that records high-temperature ductile deformation. We used a multidisciplinary approach to document the tectono-metamorphic evolution of the shear zone and its role during spreading of the western Tethys. In addition, we used zircon U–Pb ages to date formation of the gabbroic lower crust in this sector of the Apennines. Our results indicate that the CSZ rooted below the brittle–ductile transition at temperature above 800 °C. A high-temperature ductile fabric was overprinted by fabrics recorded during progressive exhumation up to shallower levers under temperature b500 °C.Wesuggest that the CSZ may represent the deep root of a detachment fault that accomplished exhumation of an ancient oceanic core complex (OCC) in between two stages of magmatic accretion.We suggest that the CSZ represents an excellent on-land example enabling to assess relationships between magmatism and deformation when extensional oceanic detachments are at work

The Intra-Pontide ophiolites in Northern Turkey revisited: From birth to death of a Neotethyan oceanic domain

The Anatolian peninsula is a key location to study the central portion of the Neotethys Ocean(s) and to understand how its western and eastern branches were connected. One of the lesser known branches of the Mesozoic ocean(s) is preserved in the northern ophiolite suture zone exposed in Turkey, namely, the Intra-Pontide suture zone. It is located between the Sakarya terrane and the Eurasian margin (i.e., Istanbul-Zonguldak terrane) and consists of several metamorphic and non-metamorphic units containing ophiolites produced in supra-subduction settings from the Late Triassic to the Early Cretaceous. Ophiolites preserved in the metamorphic units recorded pervasive deformations and peak metamorphic conditions ranging from blueschist to eclogite facies. In the non-metamorphic units, the complete oceanic crust sequence is preserved in tectonic units or as olistoliths in sedimentary mélanges. Geochemical, structural, metamorphic and geochronological investigations performed on ophiolite-bearing units allowed the formulation of a new geodynamic model of the entire "life" of the Intra-Pontide oceanic basin(s). The reconstruction starts with the opening of the Intra-Pontide oceanic basins during the Late Triassic between the Sakarya and Istanbul-Zonguldak continental microplates and ends with its closure caused by two different subductions events that occurred during the upper Early Jurassic and Middle Jurassic. The continental collision between the Sakarya continental microplate and the Eurasian margin developed from the upper Early Cretaceous to the Palaeocene. The presented reconstruction is an alternative model to explain the complex and articulate geodynamic evolution that characterizes the southern margin of Eurasia during the Mesozoic era. Keywords: Intra-Pontide suture zone, Central Pontides, Northern Turkey, Ophiolites, Neotethys Ocean, Geodynamic

the intra pontide suture zone in the tosya kastamonu area northern turkey

ABSTRACTWe present the first detailed geological map of the tectonic units documented in the easternmost branch of the Intra-Pontide suture (IPS) zone in the Tosya-Kastamonu area (Northern Turkey). The Main Map is at 1:50,000 scale and covers an area of about 350 km2. It derived from 1:25,000 scale classic field mapping and represents a detailed overview of the complexities documented in the IPS zone, a tectonic nappe stack originating from the closure of the Intra-Pontide Oceanic basin and the subsequent collision between the Istanbul-Zonguldak terrane and the Sakarya composite terrane. The map shows the orientations of superposed foliations, fold axes and mineral lineations on the basis of geometric cross-cutting relationships documented within the five tectonic units of the IPS zone and provides information on its present-day architecture resulting from activity of the North Anatolian Fault

Pulmonary arterial hypertension and interstitial lung fibrosis in systemic sclerosis: One-stop shop assessment with cardiac and chest ultrasound

Background: Interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH) are common complications of systemic sclerosis (SSc). Echocardiography evaluates PAH, and chest sonography detects even mild ILC as ultrasound lung comets (ULC), i.e. multiple comet-tails fanning out from the lung surface and originating from subpleural interlobular septa thickened by fibrosis. Aim: to assess ILD and PAH by integrated cardiac and chest ultrasound in SSc. Materials and methods: We enrolled 30 consecutive SSc patients (age=54?13 years, 23 females) in the Rheumatology Clinic of Pisa University. In all, we assessed Systolic Pulmonary Arterial Pressure (SPAP), from maximal velocity of tricuspid regurgitation flow, and ULC score with chest sonography (summing the number of ULC from each scanning space of anterior and posterior right and left chest, from second to fifth intercostal space). All patients underwent plasma assay for anti-topoisomerase antibodies (anti-Scl70), associated with development of pulmonary fibrosis. Twenty-eight patients also underwent High Resolution Computed Tomography, HRCT (from 0=no fibrosis to 3=honey combing). Results: ULC number - but not SPAP - was correlated to HRCT fibrosis and presence SSc-70 antibodies (see figure). ULC number was similar in localized or diffuse forms (16?20 vs. 21?19, p=ns) and was unrelated to SPAP (r=0.216, p=ns). Conclusions: Cardiac and chest sonography assessment of SPAP and ULC allow a complete, simple, radiation-free characterization of vascular and interstitial lung involvement in SSc - all in one setting and with the same instrument, same transducer and the same sonographer. In particular, ULC number, but not SPAP, is associated with HRCT evidence of lung fibrosis and presence of Scl-70 antibodies

Ultrasound lung comets in systemic sclerosis: a chest sonography hallmark of pulmonary interstitial fibrosis

Objective. To assess the correlation between ultrasound lung comets (ULCs, a recently described echographic sign of interstitial lung fibrosis) and the current undisputed gold-standard high-resolution CT (HRCT) to detect pulmonary fibrosis in patients with SSc. Methods. We enrolled 33 consecutive SSc patients (mean age 5413 years, 30 females) in the Rheumatology Clinic of the University of Pisa. We assessed ULCs and chest HRCT within 1 week independently in all the patients. ULC score was obtained by summing the number of lung comets on the anterior and posterior chest. Pulmonary fibrosis was quantified by HRCT with a previously described 30-point Warrick score. Results. Presence of ULCs (defined as a total number more than 10) was observed in 17 (51%) SSc patients. Mean ULC score was 3750, higher in the diffuse than in the limited form (7366 vs 2135; P<0.05). A significant positive linear correlation was found between ULCs and Warrick scores (r?0.72; P<0.001). Conclusions. ULCs are often found in SSc, are more frequent in the diffuse than the limited form and are reasonably well correlated with HRCT-derived assessment of lung fibrosis. They represent a simple, bedside, radiation-free hallmark of pulmonary fibrosis of potential diagnostic and prognostic value