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Gypsum beds host the majority of the caves in the north-eastern flank of the Apennines, in the Emilia Romagna region (Italy). More than six hundred of these caves have been surveyed, including the longest known epigenic gypsum cave systems in the world (Spipola-Acquafredda, ~11km). Although this area has been intensively studied from a geological point of view, the age of the caves has never been investigated in detail. The rapid dissolution of gypsum and uplift history of the area have led to the long-held view that speleogenesis commenced only during the last 130 000years. Epigenic caves only form when the surface drainage system efficiently conveys water into the underground. In the study area, this was achieved after the dismantling of most of the impervious sediments covering the gypsum and the development of protovalleys and sinkholes. The time necessary for these processes can by constrained by understanding when caves were first formed. The minimum age of karst voids can be indirectly estimated by dating the infilling sediments. U-Th dating of carbonate speleothems growing in gypsum caves has been applied to 20 samples from 14 different caves from the Spipola-Acquafredda, Monte Tondo-Re Tiberio, Stella-Rio Basino, Monte Mauro, and Castelnuovo systems. The results show that: (i) caves have been forming since at least ~600 kyr ago; (ii) the peak of speleogenesis was reached during relatively cold climate stages, when rivers formed terraces at the surface and aggradation caused paragenesis in the stable cave levels; (iii) ~200 000years were necessary for the dismantling of most of the sediments covering the karstifiable gypsum and the development of a surface mature drainage network. Besides providing a significant contribution to the understanding of evaporite karst evolution in the Apennines, this study refines our knowledge on the timescale of geomorphological processes in a region affected by rapid uplifting.

The Mediterranean area is a densely populated region characterised by an extremely complex atmospheric circulation, which is particularly sensitive to any modification of air mass dynamics. Thus, the understanding of past climate fluctuations in this area is of great importance to gain insight in the pattern of regional climate variability in response to global climate changes. The central Mediterranean area displayed contrasting climatic responses to atmospheric circulation re-organization following the last glacial period: drier/wetter conditions lasted until about 4.5 ka in the northern/southern regions, followed by an opposite trend. To better understand Holocene climate dynamics in the Balkans, a region where only few palaeoclimate reconstructions are available, five stalagmites were collected from two Bosnian caves. Rainfall and cave monitoring was set up in order to understand present day cave hydrology and better interpret the climate and/or environmental signal transfer to the karst. All stalagmites were dated using the U-Th method. Stable carbon and isotope ratios were analysed along the growth axis. Indeed, these values can provide information about temperature, precipitation regime and vegetation cover if calcite is deposited close to isotopic equilibrium conditions. Unfortunately, stable isotope profiles were noisy and not interpretable straightforwardly. Therefore, a multi proxy approach was adopted, coupling stable isotope and trace element profiles with detailed petrographic observations. This allowed for the interpretation of geochemical proxies and petrography variations in relation to hydrological changes. In particular, a trend towards relatively drier conditions appears since about 4 kyr, suggesting a local response to climate change similar to the one of the southern Mediterranean sites. A marginal part of this project involved the examination of a dark lamina deposited around 1.2 ka in the 4 samples from Mračna Pećina cave. This layer, appearing fluorescent under the fluorescence optic microscope, was identified with SEM observation, which demonstrated its soot nature.

International audience; In questa breve nota vengono illustrati i processi e meccanismi che hanno portato alla formazione dei sistemi carsici nelle aree gessose di Brisighella e Rontana. La morfologia delle grotte indica una loro forte influenza strutturale ed una loro formazione abbastanza recente, almeno rispetto ad altre zone della Vena del Gesso, avvenuta probabilmente nell'arco degli ultimi 20.000 anni. Le da-tazioni U/Th di alcune colate carbonatiche in alcune di queste grotte sembrano avvalorare questa ipotesi. Resti e frammenti di antiche grotte e colate (100 ka) sono state trovate nella parte alta dei rilievi e future datazioni potranno fornire ulteriori elementi. Parole chiave: Gessi, speleogenesi, datazioni U/Th, geomorfologia. Abstract In this short note, the processes and mechanisms of formation of the gypsum karst systems in the areas of Brisighella and Rontana (Messinian Gypsum outcrop of the Vena del Gesso romagnola, Northern Italy) are outlined. The general shape of the caves shows them to be deeply influenced by the structural context, and indicates them to have formed rather recently, respect to other areas in the Vena del Gesso, probably in the last 20,000 years. The U/Th dating of some carbonate speleothems in different caves seems to support this hypothesis. Fragments of old flowstones (100 ky) and cave conduits have been found in the higher parts of the gypsum ridge, and future U/Th dating might shed more light on the timing of speleogenesis.

In Emilia-Romagna la stragrande maggioranza delle grotte si sviluppa nei gessi, sia triassici che messiniani. Tali rocce evaporitiche, pur rappresentando solo l’1% delle superfici affioranti, ospitano oltre 600 grotte, tra cui la grotta epigenica nei gessi più lunga del mondo (il Sistema Spipola-Acquafredda nei gessi Bolognesi con oltre 11 km di passaggi rilevati) e quella più profonda (il Sistema del Monte Caldina, profondo 265 metri). A causa della rapida dissoluzione del gesso queste grotte sono sempre state considerate di genesi relativamente recente (ultimi 20000 anni o poco più). In presenza di importanti concentrazioni di CO2, dalle acque sature in calcio e solfati presenti in queste cavità naturali, precipita calcite portando alla formazione di concrezioni carbonatiche. Tali concrezioni, diffuse in molte grotte emiliano-romagnole, possono essere datate con il metodo dell’U/Th, fornendo delle età minime di formazione dei condotti in cui si sono depositate. Nell’ambito di due tesi di dottorato sono state campionate e datate concrezioni di calcite in una decina di grotte e località esterne della Vena del Gesso e dei Gessi Bolognesi. Tali analisi hanno identificato colate con età fino a 316 mila anni, testimoniando che le grotte esistevano già da allora. Il sistema carsico più antico ancora attivo oggi è quello del Re Tiberio, nella Vena del Gesso, che ha iniziato a formarsi almeno 130 mila anni fa

International audience; The Mediterranean area is a hotspot for present day and future climate change. The understanding of past climate dynamics in this area is of great importance to gain insight in the pattern of regional climate variability in response to hemispheric and global climate changes. In the central Mediterranean, contrasting climate responses have been observed during the last 12 ka with drier/wetter conditions in the northern/southern regions lasting until about 6-5 ka, followed by a trend toward the opposite conditions. Carbonate mineral stalagmites are continental archives able to provide simultaneous information about past climate and environmental changes. With the aim to get a deeper understanding of Holocene climate dynamics in the Balkan Peninsula, five stalagmites were collected from two Bosnian caves (Govještica and Mračna Pećina; Prača Valley) in the frame of a PhD project involving the Universities of Bologna (Italy) and Savoie Mont Blanc (France) with the collaboration of the University of Melbourne (Australia). Here we present the multiproxy methodological approach adopted for the study of these samples and some anticipations of the major findings.

International audience

Poster; International audience

International audience; Carbonate speleothems record a series of environmental and climatic information (McDermott, 2004). Their mere presence in a cave signifies that water was present in the karst system and conditions were adequate to stimulate supersaturation with respect CaCO3. The most exploited geochemical proxies are oxygen (δ18O) and carbon (δ13C) stable isotopes. Furthermore, speleothems are precisely datable. This permits to accurately constrain the time period(s) during which the cave system was capable of producing speleothems and to insert the proxies data into a rigid timeframe. Although speleothems have occupied a key role in “palaeo” science over the last twenty years (Henderson, 2006), there is a striking gap in the literature. All previous studies have been based on carbonate speleothems coming from limestone/dolostone karst. The potential of speleothems sampled in non-calcareous caves for palaeoclimate and palaeoenvironmental research is essentially unexplored. In this work we present several applications of the study of speleothems sampled in gypsum caves (Northern Apennines). The U-Th dating of five speleothems grew in the Monte Tondo karst system allowed to evaluate the climate- driven incision/aggradation of the Senio valley at intra-Milankovitch timescale. This study suggests that speleogenetic processes were active during relative cold stages, when the local base level stabilized a new altitudinal position and the scarcity of vegetation on the valley slopes favored the flux of sediments forming the river terraces. On the contrary, speleothems grew during periods of relative warm and wet conditions over the last 125,000 years, and their dating gives the minimal age of the cave where they were found. Furthermore, speleothems were sampled in five karst system nearby Monte Tondo; twenty more samples were dated with the U-Th method (~100 ages produced) and analyzed for δ18O and δ13C. Our results show that 1) the production of speleothems from gypsum caves responds to strict climatic and environmental parameters; 2) the stable isotopic composition is influenced by the amount of rainfall reaching the cave- site at the time of the formation of the speleothems. Interestingly, some of the speleothems reported an unexpected old age. This permitted the chronological revision of the inception of the speleogenetic activity in the Northern Apennines that, until this date, was considered to be occurred during the last 130,000 years. Caves were instead forming at least 450 ka, ~350 kyrs after the regression of the Adriatic Sea. This lapse was necessary for the erosion of most of the sediments covering the gypsum beds and the maturation of the drainage network, which facilitated karst infiltration in trough sinkholes and blind valleys.

Poster; International audience

Poster; International audience

International audience; In the framework of a PhD thesis at the University of Bologna and the University of Savoie (France), and in collaboration with the University of Melbourne (Australia), an ambitious scientific project is being carried out with the aim of finding palaeoclimatic records in speleothems sampled in caves of Italy and the Dinaric Karst. In this first sampling phase, thanks to the collaboration with local cavers, already broken stalagmites and flowstones have been taken in caves of Apulia, Emilia-Romagna, Trieste, Slovenia, and Bosnia Erzegovina. The samples have been cut along their length and polished. The bottom and top of the most promising samples (with well visible growth layers, clean primary calcite, without evident signs of recrystallization) has been dated to get their age of growth. The following microdrill sampling has allowed to take powders to be analysed at Mass Spectrometer for the stable isotopes of oxygen and carbon. These studies will allow to reconstruct the climate of the past in the areas of these caves, delivering a valid contribution to the palaeoclimate studies in the Central Mediterranean.

International audience; A public water supply well field, composed by 8 wells attaining a depth between 32 and 62 m b.g.s. and pumping out more than 400 L/s to about 300.000 inhabitants (Pescara province, Abruzzo region, Central Italy), has been involved for more than 20 years, from the opening in 1984 to the decomissioning in 2007, by a contamination of chlorinated aliphatics (PCE, TCE, TCM, CT). The well field is located in the narrow and long alluvial valley of the Pescara river surrounded by important limestone aquifers of Central Apennines. About 2 km upstream, at the confluence of the Tirino river with the Pescara river, is located one of the oldest chemical and petrochemical plant (Bussi sul Tirino plant) in Italy. It dates back to the end of the nineteenth century and with a production of chloromethanes active from the 60's to 2007. On 2005, a huge illegal dump of industrial wastes (more than 3 hectares in size) was discovered in the alluvial valley floor of the Pescara river during an investigation of the public prosecutor of the Pescara court. The valley of the Pescara river is filled with a complex assemblage of porous (alluvial gravels and sands, debris) and fractured (travertines) high permeability aquifers intermingled with silts and clays of lacustrine or alluvial origin. The lateral recharge from the Pescara river and/or surrounding limestones is such to induce a high dilution effect to the dissolved contaminants originated at the source. In order to apportion the source of contamination, in terms of location and of process of wastes generation, in range of the action at the Court of Assizes of Chieti, an hydrogeological investigation has been performed, supported by the Italian Attorney General. CSIA (Carbon Stable Isotope Analysis) of chlorinated compounds, integrated by chlorine fingerprinting on PCE, was adopted as a main tool of source apportionment of chlorinated pitches production process. In order to enhance the mass recovery of chlorinated compounds by low flow sampling on 25 boreholes between the source and the receptor, a preliminary flowmeter survey was performed. This allowed to identify the proper sampling location along the screen of the boreholes. The isotopic affinity of the compounds, detected at the well field, with the production process of chlorinated pitches has been clearly put in evidence as a consequence of the strong deplenishment of delta13C values. Borehole flowmetering and isotopic fingerprinting support source apportionment of a public water supply well field contaminated by chlorinated pitches (Bussi sul Tirino site, Abruzzo Region, Italy) | Request PDF. Available from: https://www.researchgate.net/publication/282314549_Borehole_flowmetering_and_isotopic_fingerprinting_support_source_apportionment_of_a_public_water_supply_well_field_contaminated_by_chlorinated_pitches_Bussi_sul_Tirino_site_Abruzzo_Region_Italy [accessed Oct 15 2018].

A public water supply well field, composed by 8 wells attaining a depth between 32 and 62 m b.g.s. and pumping out more than 400 L/s to about 300.000 inhabitants (Pescara province, Abruzzo region, Central Italy), has been involved for more than 20 years, from the opening in 1984 to the decomissioning in 2007, by a contamination of chlorinated aliphatics (PCE, TCE, TCM, CT). The well field is located in the narrow and long alluvial valley of the Pescara river surrounded by important limestone aquifers of Central Apennines. About 2 km upstream, at the confluence of the Tirino river with the Pescara river, is located one of the oldest chemical and petrochemical plant (Bussi sul Tirino plant) in Italy. It dates back to the end of the nineteenth century and with a production of chloromethanes active from the 60's to 2007. On 2005, a huge illegal dump of industrial wastes (more than 3 hectares in size) was discovered in the alluvial valley floor of the Pescara river during an investigation of the public prosecutor of the Pescara court. The valley of the Pescara river is filled with a complex assemblage of porous (alluvial gravels and sands, debris) and fractured (travertines) high permeability aquifers intermingled with silts and clays of lacustrine or alluvial origin. The lateral recharge from the Pescara river and/or surrounding limestones is such to induce a high dilution effect to the dissolved contaminants originated at the source. In order to apportion the source of contamination, in terms of location and of process of wastes generation, in range of the action at the Court of Assizes of Chieti, an hydrogeological investigation has been performed, supported by the Italian Attorney General. CSIA (Carbon Stable Isotope Analysis) of chlorinated compounds, integrated by chlorine fingerprinting on PCE, was adopted as a main tool of source apportionment of chlorinated pitches production process. In order to enhance the mass recovery of chlorinated compounds by low flow sampling on 25 boreholes between the source and the receptor, a preliminary flowmeter survey was performed. This allowed to identify the proper sampling location along the screen of the boreholes. The isotopic affinity of the compounds, detected at the well field, with the production process of chlorinated pitches has been clearly put in evidence as a consequence of the strong deplenishment of delta13C values.

Poster; International audience

Similarly to the effects of current climate change, the last deglaciation (Termination I) rapidly altered northern latitude temperatures and ice-sheet extent, as well as the Atlantic Meridional Overturning Circulation. However, it is still unclear how these changes propagated and impacted the central Mediterranean continental rainfall variability. This prevents a full understanding on how global warming will affect Mediterranean areas in the future. Here, we present a high-resolution reconstruction of rainfall changes in the central Mediterranean across Termination I, based on a novel δ18O time series from a southern Italian stalagmite. Across Termination I the availability of Atlantic moisture varied in response to northern latitude temperature increases (decreases) and ice-sheet decreases (increases), promoting a higher (lower) intensity of the Atlantic Meridional Overturning Circulation, and resulting in a relatively wetter (drier) climate in the Mediterranean. In the light of future warming, this study emphasises the role of high-latitude climate changes in causing rainfall variation in highly populated Mediterranean areas.

Roman-period extractive sites in gypsum outcrops are very rare, and most have become very degraded by later weathering or quarrying activities. This paper describes, using laser scanning, photogrammetry and survey using a UAV-based survey, the uniquely well-preserved Roman-period gypsum quarry of Ca’ Castellina (Northern Apennines, Italy). This site was excavated only in the last few years and the excavations have brought to light some gypsum blocks and the ancient quarry benches showing excavation marks, the remains of a rectangular building and a great number of artefacts that range between the Protohistoric Period and the modern times. The size of the extracted blocks, the extraction methodologies and the age of a charcoal fragment (361 – 178B CE) found immediately at the contact between the gypsum quarry floor and the infilling sediments date the quarry back to the Roman age. Archaeological evidences demonstrate the building to have been used for a short period of time during the XVI-XVII century. Immediately after its abandonment most of the quarry floor has been covered with a thick detrital layer, protecting it from dissolution (fossilizing this floor and leaving it as if it was abandoned very recently), whereas the naked or poorly covered floor of this quarry has been subjected to dissolution phenomena of the exposed gypsum rocks, with a lowering of the surface, the smoothening of the corners and the formation of a set of deeply carved karren features. A 3D survey using both a laser scanning instrument and a drone-mounted photo camera have allowed to get precise measures on the size of the blocks that were extracted in this quarry, the traces of pick axe marks, and on the dissolution morphologies that have developed on the bare gypsum rock. These typical gypsum landforms show how fast these solution forms can develop where concentrated runoff flows on bare gypsum. To prevent this exceptional archaeological extractive site of being further dissolved, it will be important to plan some measures to be put in place in order to protect this delicate historical landmark.

International audience; Tetrachloroethene and trichloroethene are typical by-products of the industrial production of chloromethanes. These by-products are known as "chlorinated pitches" and were often dumped in un-contained waste disposal sites causing groundwater contaminations. Previous research showed that a strongly depleted stable carbon isotope signature characterizes chlorinated compounds associated with chlorinated pitches whereas manufactured commercial compounds have more enriched carbon isotope ratios. The findings were restricted to a single case study and one element (i.e. carbon). This paper presents a multi-element Compound-Specific Stable Isotope Analysis (CSIA, including carbon, chlorine and hydrogen) of chlorinated aliphatic contaminants originated from chlorinated pitches at two sites with different hydrogeology and different producers of chloromethanes. The results show strongly depleted carbon signatures at both sites whereas the chlorine and the hydrogen signatures are comparable to those presented in the literature for manufactured commercial compounds. Multi-element CSIA allowed the identification of sources and site-specific processes affecting chloroethene transformation in groundwater as a result of emergency remediation measures. CSIA turned out to be an effective forensic tool to address the liability for the contamination, leading to a conviction for the crimes of unintentional aggravated public water supply poisoning and environmental disaster.

none 16 si Although outcropping rarely in Italy, evaporite (gypsum and anhydrite) karst has been described in detail since the early 20th century. Gypsum caves are now known from almost all Italian regions, but are mainly localised along the northern border of the Apennine chain (Emilia Romagna and Marche), Calabria, and Sicily, where the major outcrops occur. Recently, important caves have also been discovered in the underground gypsum mines in Piedmont. During the late 80s and 90s several multidisciplinary studies were carried out in many gypsum areas, resulting in a comprehensive overview, promoting further research in these special karst regions. More recent and detailed studies focused on the gypsum areas of Emilia-Romagna and Sicily. Sinkholes related to Permian-Triassic gypsum have been studied in Friuli Venezia Giulia. This article reviews the state of the art regarding different aspects of evaporite karst in Italy focusing on the main new results. open De Waele, J.; Piccini, L.; Columbu, A.; Madonia, G.; Vattano, M.; Calligaris, C.; D’Angeli, I.M.; Parise, M.; Chiesi, M.; Sivelli, M.; Vigna, B.; Zini, L.; Chiarini, V.; Sauro, F.; Drysdale, R.; Forti, P. De Waele, J.; Piccini, L.; Columbu, A.; Madonia, G.; Vattano, M.; Calligaris, C.; D’Angeli, I.M.; Parise, M.; Chiesi, M.; Sivelli, M.; Vigna, B.; Zini, L.; Chiarini, V.; Sauro, F.; Drysdale, R.; Forti, P.