2024, Articolo in rivista, ENG
Shehaj X.[1,2], Caporali S.[3], Palomba E.[2], Pratesi G.[1,4]
Vesicles are characteristic structures within the outer layer of many stony meteorites' fusion crusts. Although these features are well-developed in hydrated carbonaceous chondrites and some micrometeorites, their formation mechanism remains poorly understood. This study provides new insights into the understanding of physical vesiculation processes by presenting the results of vesicle size distribution (VSD)--i.e., a quantitative method for vesicle analysis--applied to the study of the Tagish Lake (C2-ung) meteorite fusion crust. Tagish Lake was chosen because it shows a scoriaceous texture and a significant number of vesicles (about 24,000 vesicles/mm2), thus allowing statistical analysis. Vesicles range from being spherical to irregular-shaped and from a few µm to ~70 µm (equivalent diameter) in size. Vesicle size distribution and cumulative number density analyses show a high nucleation event and a fractal distribution of the vesicle population, respectively. We suggest these features are due to disequilibrium degassing processes, which simultaneously produce continuous/accelerating vesicle nucleation and growth. Finally, possible analogies between the scoriaceous Tagish Lake fusion crust and the space-weathered "frothy layer" on the surface of Ryugu's grains could be found in terms of vesicularity.
DOI: 10.3390/min14010099
2024, Contributo in volume, ENG
Melaine Le Roy1,2, Susan Ivy-Ochs3,4, Kurt Nicolussi5, Giovanni Monegato6, Ju¨ rgen M. Reitner7, Renato R. Colucci8, Adriano Ribolini9, Matteo Spagnolo10 and Markus Stoffel1,11,12
The Alps have perhaps the most comprehensive chronology of Holocene glacier variations in the world. Cosmogenic nuclide data have shown that in the first centuries of the Holocene, glacier frontal positions were significantly larger than Late Holocene extents. The continued cold climate from the end of the Younger Dryas on into the Early Holocene promoted periglacial activity. Rock glaciers rapidly moved into the newly ice-free terrain and exhibited sporadic activity throughout the Holocene, with rejuvenation during the neoglacial (the last ~4.2 ka). The lack of preserved moraines between ~10.2 and 5.2 ka provides evidence of a long-lasting glacier retreat period punctuated by a number of minor advances that probably did not exceed mid-20th century ice levels. As large glaciers did not approach nor exceed their Late Holocene frontal extents during the Mid-Holocene, precise insight into the timing of these advances is only possible from the subfossil wood record. Based on the radiocarbon- and tree-ring-dated wood material, several Holocene Thermal Maximum Phases (~10.2-4.2 ka) characterised by glacier minima with smaller-than-present (CE 2000-2020) glacier extent have been recognised. From ~4.2 ka--and especially from 3.6 ka--the frequency and magnitude of glacier advances increased markedly. Notable maxima occurred at 3.5, 2.8-2.6, 2.1, 1.4 and 1.15 ka. The 'Little Ice Age' (LIA), 0.74-0.14 ka (CE 1260-1860)--characterised by several maxima with similar extent--is exceptionally well understood in the Alps. Prominent lateral moraines, which are a widespread feature of the high Alpine landscape and are often referred to as 'LIA moraines', were actually incrementally built during the neoglacial. Strong paraglacial activity linked with ongoing glacier wastage as a result of climate warming currently endangers the preservation of some of these Late Holocene landforms and the information they contain.
2024, Articolo in rivista, ENG
Lukas Rettig a,*, Sarah Kamleitner b, Paolo Mozzi a, Adriano Ribolini c, Susan Ivy-Ochs b, Brice R. Rea d, Giovanni Monegato e, Marcus Christl b, Matteo Spagnolo d
We present new chronological data and Equilibrium Line Altitude (ELA) information for palaeoglaciers in the Maritime Alps during the Last Glacial Maximum (LGM) and the early deglaciation. Three relatively small catchments were investigated to test if the response of small (1-10 km2) glaciers to LGM climatic forcing was distinguishable from that of larger glacial systems. Palaeoglacier geometries and ELAs were reconstructed using geomorphological evidence and toolboxes in a geographic information system. Chronological control was provided through 10Be surface exposure dating of erratic boulders located on frontal and lateral moraine ridges. Our data indicate two phases of glacier advance or stabilisation in the Maritime Alps, the first occurring at ca. 25 to 24 ka and the second at ca. 20.5 to 19 ka. This is consistent with ages that have been reported from larger outlet lobes along the south-western Alpine fringe, where the second LGM advance is usually preserved in the form of a recessional moraine. Within the uncertainty of the dating technique, there are no distinguishable differences between the responses of small and large Alpine glaciers to the LGM climate. The reconstructed ELAs for palaeoglaciers in the Maritime Alps indicate a considerable variability, which appears to be linked to differences in received solar radiation, from ca. 1600 m a.s.l. for north-facing cirque glaciers to almost 2000 m a.s.l. for glaciers with a southerly aspect. We argue that such influence of solar radiation needs to be considered when using ELAs for palaeoclimatic inferences at regional scales. The calculated ELAs are up to 450 m higher than those in the northern Apennines or the Corsican mountains, indicating a relatively dry LGM climate on the Italian side of the Maritime Alps.
2024, Articolo in rivista, ENG
Cinzia Scaggion 1,2*, Maurizio Marinato 3 , Gregorio Dal Sasso 4 , Luca Nodari 5 , Tina Saupe 6 , Serena Aneli 7,8 , Luca Pagani 6,7 , Christiana L. Scheib 6 , Manuel Rigo 1,4 & Gilberto Artioli 1,2
Following the development of modern genome sequencing technologies, the investigation of museum osteological finds is increasingly informative and popular. Viable protocols to help preserve these collections from exceedingly invasive analyses, would allow greater access to the specimens for scientific research. The main aim of this work is to survey skeletal tissues, specifically petrous bones and roots of teeth, using infrared spectroscopy as a prescreening method to assess the bone quality for molecular analyses. This approach could overcome the major problem of identifying useful genetic material in archaeological bone collections without resorting to demanding, time consuming and expensive laboratory studies. A minimally invasive sampling of archaeological bones was developed and bone structural and compositional changes were examined, linking isotopic and genetic data to infrared spectra. The predictive model based on Infrared parameters is effective in determining the occurrence of ancient DNA (aDNA); however, the quality/quantity of aDNA cannot be determined because of the influence of environmental and local factors experienced by the examined bones during the burial period
2024, Articolo in rivista, ENG
Sanità E.[1], Di Rosa M.[1], Marroni M.[1,2], Meneghini F.[1,2], Pandolfi L.[1]
In the Northern Apennines, the Internal Ligurian Units are considered deformed and metamorphosed fragments of the Ligure-Piemontese oceanic basin. In this paper, we report on the temperature and pressure conditions of the metamorphic peak for four Internal Ligurian Units, estimated using different geothermometers and geobarometers based on the white mica and chlorite compositions. These minerals were formed during the D1 deformation phase in the pre-Oligocene. The results indicate that the Portello and Gottero units are both characterized by metamorphic conditions pertaining to low blueschists facies, while the Colli-Tavarone and Bracco-Val Graveglia Units show a lower metamorphic imprint that produces assemblages of prehnite-pumpellyite facies. The estimated geothermal gradient for the metamorphic peak achieved by the analyzed Internal Ligurian Units during the D1 phase is 7-15 oC/Km, which is indicative of deformation in a subduction setting. Under these conditions, the D1 phase developed in these units as a result of underplating at the base of the accretionary wedge during the closure of the Ligure-Piemontese basin. These data indicate a close geodynamic correlation among the Internal Ligurian Units and the ophiolite-bearing units of the Alps.
DOI: 10.3390/min14010064
2024, Articolo in rivista, ENG
Mu K.[1,2,3], Tang C.[1,2], Tosi L.[4], Li Y.[1,2], Zheng X.[1,2], Donnici S.[4], Sun J.[1,2,3], Liu J.[5], Gao X.[1,2]
Monitoring shoreline movements is essential for understanding the impact of anthropogenic activities and climate change on the coastal zone dynamics. The use of remote sensing allows for largescale spatial and temporal studies to better comprehend current trends. This study used Landsat 5 (TM), Landsat 8 (OLI), and Sentinel-2 (MSI) remote sensing images, together with the Otsu algorithm, marching squares algorithm, and tidal correction algorithm, to extract and correct the coastline positions of the east coast of Laizhou Bay in China from 1984 to 2022. The results indicate that 89.63% of the extracted shoreline segments have an error less than 30 m compared to the manually drawn coastline. The total length of the coastline increased from 166.90 km to 364.20 km, throughout the observation period, with a length change intensity (LCI) of 3.11% due to the development of coastal protection and engineering structures for human activities. The anthropization led to a decrease in the natural coastline from 83.33% to 13.89% and a continuous increase in the diversity and human use of the coastline. In particular, the index of coastline diversity (ICTD) and the index of coastline utilization degree (ICUD) increased from 0.39 to 0.79, and from 153.30 to 390.37, respectively. Over 70% of the sandy beaches experienced erosional processes. The shoreline erosion calculated using the end point rate (EPR) and the linear regression rate (LRR) is 79.54% and 85.58%, respectively. The fractal dimension of the coastline shows an increasing trend and is positively correlated with human activities. Coastline changes are primarily attributed to interventions such as land reclamation, aquaculture development, and port construction resulting in the creation of 10,000.20 hectares of new coastal areas. Finally, the use of Kalman filtering for the first time made it possible to predict that approximately 84.58% of the sandy coastline will be eroded to varying degrees by 2032. The research results can provide valuable reference for the scientific planning and rational utilization of resources on the eastern coast of Laizhou Bay.
DOI: 10.3390/rs16010185
2024, Articolo in rivista, ENG
Coletti G.[1], Bosio G.[1], Collareta A.[2], Bialik O.M.[3,4], Regattieri E.[5], Cornacchia I.[5], Insacco G.[6], Buckeridge J.[7]
Palaeoenvironmental data are fundamental in determining the manifold impacts of climate change. This paper argues that sessile barnacles are an excellent palaeoenvironmental proxy: they are present in nearly all nearshore environments, and their shell consists of diagenetically stable low-magnesium calcite and grows fast enough to record short-term variations. To demonstrate their utility, specimens from several Western Mediterranean Pliocene and Pleistocene barnacle-rich deposits are analysed herein, using for the first time a combination of sedimentology, taphonomy, stable isotope geochemistry and detailed comparisons with modern counterparts. Within shelf carbonate systems, barnacle diversity is highest in the shallow, nearshore waters and decreases moving offshore, thus providing a good proxy for the reconstruction of water depth and distance from the coastline. Barnacle taphonomy is also informative. Well-preserved complete specimens are characteristic of protected areas, whereas less well-preserved specimens occur in high-energy areas. The presence/absence of opercular plates is also particularly relevant for evaluating hydrodynamic conditions. As regards the C and O stable isotope ratios, due to the porous and coarse-grained nature of the deposits in which barnacle remains are usually found, the shells are often exposed to meteoric water percolation during diagenesis. Among the analysed specimens, only those collected from fine-grained deposits display no evidence of alteration and have isotopic ratios in line with those of their modern counterparts. These fossils display intra-shell variations that in modern barnacles have been related to short-term environmental changes (e.g., seasonal cycles). These results demonstrate that barnacles can always be useful for detailed palaeoenvironmental reconstructions based on skeletal assemblages. Furthermore, with further research aimed at gathering more data and assessing potentially interfering signals, they could become useful proxies for palaeoseasonality.
2024, Articolo in rivista, ENG
Bonazzi M.[1,2], Bonacina G.[2], Previde Massara E.[3], Piva A.[3], Scotti P.[3], Viaggi P.[3], Sanfilippo A.[1,2]
The redox sensitive elements (RSE) are indicators of organic matter (OM)-rich rocks and provide valuable information on paleoenvironmental parameters, including organic productivity, chemical evolution of water masses, ocean residence times and sea-bottom redox conditions. Yet, their potential to understand global environmental changes is hindered by the scarcity of continuous geological records, often highly fragmented in space and time. In this contribution, a large dataset from five closely spaced sedimentary sections in the Western African margin is used to reconstruct a 40 myr-long record of the redox conditions in a time spanning from the early Aptian to early-middle Campanian. Studied intervals were originally located in different positions of the embryonic Atlantic Ocean, and intercept four separated oceanic anoxic events (OAE1c, OAE1d, OAE2 and OAE3). The complete geochemical characterization revealed the changes of Mn, V, Ni, Cu, Zn, Mo, U and Se during the deposition of OM-rich sediments, as a function of their depositional environments, redox conditions, and time. It is shown that, although enrichments of RSE are triggered by increasingly reducing seafloor conditions, the extent to which these elements are retained within the sedimentary record depend on both local variations in detrital inputs and global perturbations of the marine RSE inventories. The analyses show that RSE are characteristically enriched with respect to global shale values, having geochemical characteristics (i.e., high Mo/TOC and high Mo/U) suggestive of suboxic to sulfidic conditions from the late Albian to Campanian.
2024, Articolo in rivista, ENG
Notini L.[1], Scambelluri M.[1], Tommasi A.[2], Zanetti A.[3], Ferri F.[4], Rodríguez-Vargas A.[5], Rampone E.[1]
In subduction zones, the mantle wedge is the domain where liquid phases released by the oceanic subducting plates cause mantle hydration, metasomatism, and partial melting, producting the arc crust. However, direct petrologic information on mantle wedges overlying active subduction zones remains scarce. Here we constrain key aspects of the petrological evolution of the supra-subduction mantle underneath the active volcanic district of Southern Colombia (Mercaderes) by studying a unique suite of peridotite and pyroxenite xenoliths hosted by andesites and lamprophyres. These garnet-bearing peridotite, websterite, clino- and orthopyroxenite xenoliths equilibrated between 2.5 and 4 GPa and 1100-1200 oC. The studied rocks display considerable heterogeneity in terms of lithotypes, textures, mineral abundance and extent of metasomatic overprint. Most samples display fine-grained mylonitic textures overprinting coarse-grained peridotite and garnet pyroxenite precursors; the EBSD study of undeformed garnet websterite samples suggests crystallization from melts and/or melt-rock reaction processes. Modal enrichment in clinopyroxene as well as in the alkalis and LREE contents in some garnet peridotite implies interaction with alkaline basaltic melts, whereas enrichment in silica, Pb and Sr in the garnetbearing orthopyroxenites records interaction with metasomatic, slab-derived liquids. Some garnet clinopyroxenite xenoliths display marked positive Sr anomalies and minor Eu anomalies, indicating derivation of these rocks from Mg-rich, plagioclase-bearing (and garnet-absent) low-pressure cumulates. Their equilibration in the garnet field implies that after crystallization these clinopyroxenites were transported to deeper levels in the mantle, as the result of foundering into the mantle of the dense arc roots, as already documented in Mercaderes and elsewhere in the Andes. In conclusion, the Mercaderes xenoliths probe a heterogeneous and chemically active domain of the Colombian mantle wedge, where deep sinking lower crustal rocks, melt metasomatism by distinct venues of chemically different melts, and deformation predate fast exhumation by volatile-rich melts.
2024, Articolo in rivista, ITA
Ferrando C.[1,2], Borghini G.[3], Sani C.[1], Genske F.[4], Ligi M.[5], Stracke A.[4], Sanfilippo A.[1,6]
Partial melting of mantle peridotite from which considerable amounts of melt have been extracted during prior melting episodes generates melts characterized by low incompatible element contents and very low ratios of highly to moderately incompatible elements, so-called 'ultra-depleted' melts. Reaction of peridotite with percolating ultra-depleted melts has been inferred from petrological-geochemical studies of abyssal peridotites and ophiolites. But so far, direct evidence for the existence of ultra-depleted melts, only comes from rare melt inclusions. Here, we show that a pyroxenite layer within abyssal peridotite from the Mid Atlantic Ridge (8°N, Doldrums Fracture Zone) formed by crystallization of a segregated melt that is highly depleted in incompatible elements, at >27 km-depth beneath the ridge axis (at T circa 1250 °C), and with little or no modification by interaction with the host harzburgite. During exhumation, the pyroxenite experienced decompression and partial re-equilibration under plagioclase-facies conditions (circa1060 °C and circa 15 km depth). The high Hf isotope ratio (epsilonHf = 40.3) of the pyroxenite clinopyroxene is inherited from a melt sourced from an ultra-depleted peridotite that evolved with high Lu/Hf. The associated MORB-like Nd isotope ratios (epsilonNd = 10.6), however, imply a long-term evolution of the source peridotite with composition moderately depleted in incompatible elements (rather low Sm/Nd). These compositions are different from the host harzburgite, but typical for peridotites that have melted and partially reacted with migrating melts in ancient times. Hence, the pyroxenite investigated here is a partial melt from an ultra-depleted peridotite that has become re-enriched in incompatible elements and clinopyroxene. This melt crystallized in the oceanic lithosphere, and partially re-equilibrated at low pressure during exhumation. Overall, our results show that renewed melting of ultra-depleted peridotites with a complex history of prior melting and melt-rock reaction occurs, and that such melts migrate through the sub-ridge mantle, and can thus contribute to mid ocean ridge magmatism, although to a still unknown extent.
2024, Articolo in rivista, ENG
Benetti B.[1,2], da Costa Campos Neto M.[2], Carosi R.[1], Luvizotto G.[3], Iaccarino S.[1], Montomoli C.[1,4]
The metamorphic and kinematic evolution of medium-high grade rocks of the Andrelândia Nappe System (ANS), the orogenic wedge of the Southern Brasilia Orogen (SBO), was investigated in this work. Field and microstructural observations were combined with metamorphic petrology (i.e., iterative thermodynamic modeling) and monazite petrochronology to reconstruct the tectono-metamorphic history of the ANS rocks. The Liberdade Nappe experienced prograde metamorphism at ca. 610 Ma, achieving peak metamorphic conditions of ca. 650 oC and 9.5-10 kbar. This stage was followed by isothermal decompression linked to tectonic transport toward SE, at ca. 570 Ma. On the contrary, the Andrelândia Nappe experienced prograde metamorphism later, at ca. 580 Ma, reaching peak metamorphic conditions of ca. 680 oC and 11-12 kbar. The obtained results indicate that each nappe of the Andrelândia System records a single metamorphic cycle of burial and decompression, although it took place at different ages over a period of ca. 60 myr, from 630 to 570 Ma. The nappes experienced prograde and retrograde metamorphism whose ages progressively decreased toward the bottom of the nappe stack. We attribute this pattern to propagation of older buried material from the orogenic wedge (i.e., Liberdade Nappe), via thrust-and-fold, upon recently accreted rocks (i.e., Andrelândia Nappe), conducting a younger metamorphism event on the footwall of the ductile thrusted nappes. This mechanism is consistent with the ANS in-sequence foldand-thrust architecture.
2024, Articolo in rivista, ITA
Balestrieri M.L.[1], Olivetti V.[2], Chew D.[3], Zurli L.[4], Zattin M.[2], Drakou F.[3], Cornamusini G.[4], Perotti M.[4]
We present a multidisciplinary provenance study on legacy cores drilled in the 1970s during DSDP Leg 28 at sites 271 and 272, in the central Ross Sea, Antarctica. The two sites combined provide a discontinuous glaciomarine sedimentary record covering 18 myr, from the Middle Miocene to the present day.The two boreholes are located on the continental shelf and near the edge of the Ross Ice Shelf, in the middle of the Ross Sea, at a key site close at 180° longitude that is considered to represent the present confluence between ice flows fed by West Antarctica and East Antarctica. The study employs Usingle bondPb dating of detrital zircons and apatites, coupled with apatite fission-track dating and trace element and REE compositions. Based on the sedimentary provenance, our data show a recurrent E-W oscillation of the confluence of the West Antarctica and East Antarctica ice flows, allowing phases of advance and retreat of the West Antarctic Ice Sheet to be inferred.
2024, Articolo in rivista, ENG
Ricci A.[1], Fiebig J.[2], Tassi F.[3,4], Hofmann S.[2], Capecchiacci F.[3,4,5], Vaselli O.[3,4]
Active volcanoes often discharge hot (T >> 100 °C) magmatic gases whose original composition has been modified through partial interaction with an externally fed hydrothermal system. The study of methane (CH4) in these volcanic discharges may provide useful information on the interplay between deep magmatic gases and shallow circulation of hydrothermal fluids. However, the origin of CH4 in high-temperature volcanic gases and the factors exerting control on its abundance and stable isotope composition are still largely unknown. Here, we present the abundances and stable isotopic composition of CH4 in hot (99-387 °C) volcanic gases from the La Fossa volcanic crater of Vulcano Island (Southern Italy). Our investigation revealed low (<1.5 micromol/mol) CH4 concentrations and an extraordinarily large variability in CH4 stable isotopic composition, with delta13C and delta2H values being positively correlated and varying from -35 to -9.2 %o and -670 to -102 %o, respectively. Notably, CH4 isotopes measured at Vulcano almost encompasses the global-scale variability observed in natural fluids, with delta2H values <= -500 %o being the first ever reported in nature. Gases showing extremely negative delta13C-CH4 and delta2H-CH4 values systematically display higher CH4 abundances. We propose two possible scenarios in order to explain the observed huge variation in delta13C and delta2H: (1) mixing of 13C- and 2H-depleted CH4 with 13C- and 2H-enriched CH4 of thermogenic origin formed under hydrothermal conditions; (2) post-genetic removal and isotopic alteration of 13C- and 2H-depleted CH4 occurring during the ascent of volcanic gases. Comparing our dataset with available isotopic data from naturally occurring and artificially produced CH4, a thermogenic origin for the isotopically light CH4 seems unlikely. We postulate that the 13C- and 2H-depleted CH4 may have formed via kinetically-controlled abiotic synthesis through CO (or CO2) hydrogenation reactions in the hot ascending gas phase, possibly at temperatures intermediate between those typical of magmatic and hydrothermal conditions.
2024, Articolo in rivista, ENG
Alessia Guerrieri, Isabel Cantera, Silvio Marta, Aurélie Bonin, Alexis Carteron, Roberto Ambrosini, Marco Caccianiga, Fabien Anthelme, Roberto Sergio Azzoni, Peter Almond, Pablo Alviz Gazitúa, Sophie Cauvy-Fraunié, Jorge Luis Ceballos Lievano, Pritam Chand, Milap Chand Sharma, John Clague, Justiniano Alejo Cochachín Rapre, Chiara Compostella, Rolando Cruz Encarnación, Olivier Dangles, Philip Deline, Andre Eger, Sergey Erokhin, Andrea Franzetti, Ludovic Gielly, Fabrizio Gili, Mauro Gobbi, Sigmund Hågvar, Norine Khedim, Rosa Isela Meneses, Gwendolyn Peyre, Francesca Pittino, Angela Proietto, Antoine Rabatel, Nurai Urseitova, Yan Yang, Vitalii Zaginaev, Andrea Zerboni, Anaïs Zimmer, Pierre Taberlet, Guglielmina Adele Diolaiuti, Jerome Poulenard, Diego Fontaneto, Wilfried Thuiller, Gentile Francesco Ficetola
The worldwide retreat of glaciers is causing a faster than ever increase in ice-free areas that are leading to the emergence of new ecosystems. Understanding the dynamics of these environments is critical to predicting the consequences of climate change on mountains and at high latitudes. Climatic differences between regions of the world could modulate the emergence of biodiversity and functionality after glacier retreat, yet global tests of this hypothesis are lacking. Nematodes are the most abundant soil animals, with keystone roles in ecosystem functioning, but the lack of global-scale studies limits our understanding of how the taxonomic and functional diversity of nematodes changes during the colonization of proglacial landscapes. We used environmental DNA metabarcoding to characterize nematode communities of 48 glacier forelands from five continents. We assessed how different facets of biodiversity change with the age of deglaciated terrains and tested the hypothesis that colonization patterns are different across forelands with different climatic conditions. Nematodes colonized ice-free areas almost immediately. Both taxonomic and functional richness quickly increased over time, but the increase in nematode diversity was modulated by climate, so that colonization started earlier in forelands with mild summer temperatures. Colder forelands initially hosted poor communities, but the colonization rate then accelerated, eventually leveling biodiversity differences between climatic regimes in the long term. Immediately after glacier retreat, communities were dominated by colonizer taxa with short generation time and r-ecological strategy but community composition shifted through time, with increased frequency of more persister taxa with K-ecological strategy. These changes mostly occurred through the addition of new traits instead of their replacement during succession. The effects of local climate on nematode colonization led to heterogeneous but predictable patterns around the world that likely affect soil communities and overall ecosystem development.
DOI: 10.1111/gcb.17057
2024, Articolo in rivista, ENG
Scaggion C.[1,2], Dal Sasso G.[3,4], Nodari L.[5], Pagani L.[6], Carrara N.[7], Zotti A.[8], Banzato T.[8], Usai D.[4], Pasqualetto L.[9]i , Gadioli G.[7], Artioli G.[1,2]
Bones and teeth from archaeological records are direct evidence of past individuals and they represent valuable archives for palaeo-anthropological and palaeoenvironmental studies. However, pristine information may be obliterated by the diagenetic alteration of bone specimens. Thus, defining in detail their preservation state is fundamental to assess the potential of extracting information about the past life of the individual, as well as to investigate the palaeo-environment at the burial site. For this reason, we have selected a set of archaeological samples (petrous bones and tooth roots) of different origin and chronology that have experienced diverse environmental and burial conditions, from arid and semi-arid to temperate regions in a time span from prehistoric to fresh bones. Thus, the selected samples underwent a variety of diagenetic processes, resulting in different types and extent of alteration patterns. Here we have applied a minimally-invasive sampling strategy and an analytical protocol based on Fourier transform infrared spectroscopy (FTIR) in order to ensure the investigation of a statistically significant set of samples. We provide a method to describe and quantify the changes in the physico-chemical properties of both the organic and inorganic constituents of bones, by establishing a set of parameters calculated from the FTIR spectra and evaluating their sensitivity in describing the alteration types and extent in bone specimens. Through FTIR spectral analysis, we have defined the most suitable parameters to effectively describe the alteration degree of bone specimens. Notably, the results have shown that, despite the complexity of multifactorial diagenetic processes, their measurable effects on differently altered bones can be described by a common mechanism. This indicates a progressive loss of collagen which is paralleled to the recrystallization of bioapatite and the loss of structural carbonate, regardless of the origin and chronology of the specimens. Thus, here we propose an FTIR-based model for bone diagenesis of general validity, highlighting that distinct diagenetic processes affecting the archaeological bones have acted according to common alteration mechanisms.
2023, Articolo in rivista, ENG
Baroni C.[1], Bondesan A.[2], Carturan L.[3], Chiarle M.[4], Scotti R.[5]
Baroni C., Bondesan A., Carturan L., Chiarle M., Scotti R., Annual glaciological survey of Italian glaciers (2022). (IT ISSN 0391-9838, 2023). Results of the annual glaciological survey (2022) conducted on Italian glaciers are here presented. About 250 volunteers operated last year in the three Alpine sectors (Piemonte - Valle d'Aosta, Lombardy and Triveneto) and in the Apennines (Calderone Glacier, Gran Sasso Group) observing two hundred and two glaciers. One hundred and eighteen glaciers were observed in the Piemonte - Valle d'Aosta sector while frontal variation was measured at the snout of sixty glaciers. Twenty-seven and fifty-seven glaciers were visited in the Lombardy Sector and in the Triveneto Sector, respectively (twenty-one and forty-three of which were measured, respectively). Mass balance measurements were conducted on nineteen Italian glaciers during the 2021-2022 hydrological year: four glaciers in the Western Alps (Piemonte - Valle d'Aosta sector), fourteen in the Eastern Alps (three in the Lombardy Sector, the other glaciers in the Triveneto Sector) and one in the Central Apennines.
2023, Articolo in rivista, ENG
Kustatscher E.[1,2,3], Nützel A.[2,3], Roghi G.[4], Gianolla P.[5]
Rinaldo Zardini (1902-1988) was an Italian palaeontologist and botanist born in Cortina d'Ampezzo. Having a background as a professional photographer, he was able to illustrate his collection of mostly tiny fossils in high definition. For his significant contributions to the field of palaeontology he received an honorary degree from the University of Modena. Here we highlight the extent of his scientific interest and his enduring scientific legacy in geology, palaeozoology and palaeobotany.
2023, Articolo in rivista, ENG
Di Rosa M.[1], Frassi C.[1], Marroni M.[1,2], Pandolfi L.[1], Malasoma A.[3], Meneghini F.[1,2]
The Lower Units of Alpine Corsica, France, are fragments of continental crust strongly deformed and metamorphosed under high-pressure metamorphic conditions. Three slices of Lower Units are well exposed in the area between the Asco and Tavignano valleys, Central Corsica. Despite their complex structural setting, they provide the opportunity for a reconstruction of the pristine stratigraphic setting of the Lower Units. In our reconstruction, these units consist of a Paleozoic basement topped by Triassic to Early Jurassic sedimentary rocks unconformably covered by Middle to Late Eocene foredeep deposits. However, the three units exposed in the study area display strong differences mainly in the thickness of the Mesozoic sequence. These differences are here interpreted as acquired during the first stage of the rifting process in a setting controlled by normal faults. During the collision-related tectonics and the accretion of the Lower Units to the Alpine orogenic wedge, these normal faults were probably reactivated with a reverse kinematics. The stratigraphic logs of the Lower Units strictly resemble those of the Pre-Piedmont Units from Western Alps. This similarity indicates a common origin of the Lower Units and the Pre-Piedmont Units from the same domain (i.e., the European distal continental margin).
2023, Articolo in rivista, ENG
Ciani F.[1], Fornasaro S.[2], Benesperi R.[3], Bianchi E.[3], Cabassi J.[4], Di Nuzzo L.[3], Grifoni L.[3], Venturi S.[1,4], Costagliola P.[1], Rimondi V.[1]
Biomonitoring studies are often employed to track airborne pollutants both in outdoor and indoor environments. In this study, the mercury (Hg) sorption by three biomonitors, i.e., Pinus nigra bark, Pseudovernia furfuracea lichen, and Hypnum cupressiforme moss, was investigated in controlled (indoor) conditions. In comparison to outdoor environments, controlled conditions ofer the opportunity to investigate more in detail the variables (humidity, temperature, pollutants speciation, etc.) that control Hg uptake. The biomonitors were exposed in two distinct periods of the year for 2 and 12 months respectively, in the halls of the Central Italian Herbarium (Natural History Museum of the University of Florence, Italy), which are polluted by Hg, due to past plant sample treatments. The Hg sorption trend was monitored every 3 weeks by recording: (i) the Hg content in the substrata, (ii) gaseous elemental mercury (GEM) concentrations in the exposition halls, (iii) temperature, (iv) humidity, and (v) particulate matter (PM) concentrations. At the end of the experiment, Hg concentrations in the biomonitors range from 1130±201 to 293±45 microg kg-1 (max-min) in barks, from 3470±571 to 648±40 microg kg-1 in lichens, and from 3052±483 to 750±127 microg kg-1 in mosses. All the biomonitors showed the highest Hg accumulation after the frst 3 weeks of exposure. Mercury concentrations increased over time showing a continuous accumulation during the experiments. The biomonitors demonstrated diferent Hg accumulation trends in response to GEM concentrations and to the diferent climatic conditions (temperature and humidity) of the Herbarium halls. Barks strictly refected the gaseous Hg pollution, while lichen and moss accumulation was also infuenced by the climatic conditions of the indoor environment. Mercury bound to PM seemed to provide a negligible contribution to the biomonitors fnal uptake.
2023, Articolo in rivista, ENG
Alessandrino L.[1], Gaiolini M.[2], Cellone F.A.[3,4], Colombani N.[2], Mastrocicco M.[1], Cosma M.[3], Da Lio C.[3], Donnici S.[3], Tosi L.[3]
Groundwater salinization can be natural and anthropogenic in origin, although it often results from a combination of both, especially in low-lying coastal regions that are hydraulically controlled. This study proposes a method to assess the origin of salinity using environmental tracers in porewater, like Cl- and Br- , combined with depositional facies associations detected in sediment cores. Such integrated approach was tested in a target area south of the Venice Lagoon (Italy), where groundwater salinization is triggered by multiple mechanisms due to the complexity of the hydro-geomorphological environment. Batch tests were performed on sediment core samples from boreholes to quantify major anions and total inorganic N. Cl- and Br- porewater concentrations coupled with sedimentary facies association provided insights into the origin of groundwater salinity from a variety of sources, including past and present seawater intrusion, agricultural leaching, and evaporites. The strengths and limitations of the integrated approach are discussed to provide a pathway for improving water resource management and planning measures to prevent groundwater salinization in coastal areas.