Nuova classificazione biostratigrafica e geocronologica delle unità formazionali oligoceniche e neogeniche della Sardegna. Correlazioni con le omologhe unità della Corsica

Recent revisions in classification and the new definitions in the literature of late Paleogenic and Neogenic formations outcropping in the northern, central and southern Sardinia provided by the authors have led to the preparation of a complete biostratigraphic and geochronological picture of the entire Sardinian Tertiary sedimentay basin. The lithostratigraphic units, of which the measured stratigraphic sections of reference will be given in another work, were placed in the most recent and up-to-date zonal classifications of Mediterranean planktonic Foraminifers associations and calcareous plankton. In this proposal for the reclassification of the stratigraphic successions of Sardinia’s Oligocene-Neogene, three main marine sedimentation cycles are recognized. These are silicoclastics and mixed silicoclastic-carbonatic sediments, sometimes richly fossiliferous, in which are inserted volcanic products going from acid to intermediate-basic and having a calcalkaline composition (the «Oligo-Miocene volcanic cycle») almost exclusively in the Aquitanian-Late Burdigalian interval. On the basis of a comparative analysis of autochthonous benthic associations, especially those with molluscs and of the textural characteristics of the sediments, the prevalent depositional environment is that of a platform and secondly of a slope, but in some cases fluvio-lacustrine and deltaic (preliminary data on the paleo-ecological aspects are being prepared for publication). Of the three main sedimentation cycles, the first evolved between the Chattian-Aquitanian limit and the Late Burdigalian (N6 Zone); the second cycle began in the Uppermost Burdigalian, in correspondence to the upper part of the Globigerinoides trilobus Zone (N7 Zone) and closes in the Late Serravallian (G. siakensis Zone, G. siakensis - G. obliqua obliqua Subzone); finally, the third cycle begins in the Uppermost Serravallian and finishes in the Early Messinian, in correspondence to the upper part of biostratigraphic N17a Zone. The successions examined are also considered with reference to the major tectonic and volcanic events which took place in Sardinia from the Oligocene to the Pliocene within the wider context of the geodynamic evolution of the western Mediterranean area. In particular, the first two sedimentary cycles which evolved from the end of the Oligocene and the Early-Middle Miocene would appear to be closely connected with the collision and postcollision phases respectively of the northern Apennines. The northern Apennines collision phase appears to have manifested itself in Sardinia with an important transcurrent tectonic with transpressive and transtensive structures and with the development of subsidence basins of the pull-apart type in correspondence to which the first Miocene sedimentary cycle and the associated calcalkaline volcanism developed. The creation in the Burdigalian of the wide N-S Sardinian rift, in which the second Miocene sedimentary cycle evolved, is to be attributed to the subsequent phase of postcollision distension. The third Miocene sedimentary cycle becomes manifest, following a regressive phase, limited to the most subsident areas of the Logudoro -Sassari, Capo Frasca - Sinis and Cagliari regions. The marine ingression of the Early Pliocene, located in central Sardinia (Cava Fuile and Nuraghe Baboe Cabitza B nn. Formations) and in the south of the island (in drilling) is to be placed in connection with the strong resumption of the southern Tyrrhenian distensive tectonics towards the end of the Messinian and Pliocene, as well as with widespread alkaline, prevalently basaltic, volcanic activity (the «Plio-Pleistocene volcanic cycle»). In the Late-Middle Pliocene, between the Gulf of Cagliari and the Gulf of Oristano, there was the development of the Campidano graben, filled with more than 500 m of continental deposits (the Samassi Formation). The four Corsican basins (Bonifacio, Saint Florent, Francardo, the eastern Plain), in which Miocene and/or Pliocene sediments outcrop, show, starting from the summital Burdigalian, an evolution that is fairly parallel to what has been recognized in the north of Sardinia. The formations of Aghione, Saint Florent, Cala di Labra and Bonifacio are in fact partly referable to the second Sardinian sedimentary cycle. The subsequent phases characterized in Corsica by emersion, marine sedimentation (the Vadina and Urbino units), fluvio-deltaic sedimentation (the Aleria Formation) and further marine sedimentation (the Urbino, Casabianda, Propiano and Aiaccio units), are in Sardinia respectively correlated with the hiatus and/or erosion or continental sedimentation in the Late Serravillian, with the Tortonian part of the third marine sedimentation cycle (the Monte San Michele Formation), with the Messinian part of the same cycle (the Capo San Marco, Sinis and Torre del Sevo Formations) and with the Nuraghe Baboe Cabitza B (Capo San Marco) Pliocene formation

Malacofaune spiaggiate della costa occidentale della Sardegna. Fisiografia e batimetria dei fondali marini di provenienza

Herein are presented the results of research of an autoecological nature concerning beached malacological fauna gathered along the west coast of Sardinia. The resulting data contribute to defining the composition and structure of thanatocoenosis gathered at 35 biosites and allow estimation of the «bathymetric maximum» (30-40 metres) equivalent to the greatest depth at which sediments and the remains of molluscs within them are mobilized. Homogeneous «timed» sampling led to useful statistical comparisons between the different malacological associations gathered and made it possible to recognize the stocks of benthic populations most involved in the transportation of material: AP, SFBC, HP. By means of the autoecological analysis of recognized species, especially using data on texture, way of life and biocoenotic significance, the paper discusses the physiography of the sea bottoms mobilized in front of the biosites sampled. A database on the systematic taxonomy and autoecology of the 223 species identified, which represents a point of reference also in palaeoecological research into Neogenic and Quaternary fossiliferous deposits of Sardinia, is presented

Autoecologia e ambiente dei molluschi marini alloctoni raccolti in spiagge delle coste meridionale e sud-orientale della Sardegna

The present work is devoted to thanatocoenosis of beached molluscs along the south and southeaster coasts of Sardinia. In sampling the 32 biosites a homogeneous «timed» method was adopted to allow a significant statistical comparison between the different associations. Overall, 188 species of molluscs were identified. Among these were found 74 bivalves, 111 gastropods, 2 scafopods and 1 polyplacophores. These species, together with their essential synonyms, were systematically classified. The autoecological analysis of the species supplied useful information on: texture, way of life, trophic level, biocoenotic significance and bathymetric category. In particular, the structure of the associations of organisms gathered was defined and the entity of the different biocoenotic stocks represented in them was estimated. By means of the statistical analysis the possible site of the ‘bathymetric maximum’ (some 30 metres) connected with the mobilization of sediments and the remains of the molluscs contained in them was deduced, as was the biocoenosis most involved: AP, SFBC, HP). Information on the way of life, the biocoenotic significance and texture of every single species led to the drawing up of a good approximation of the physiography of the sea bottoms in front of the beaches that were sampled

Stress-induced changes to the flora in a geothermal field in central Italy

The vegetation profile and the photosynthetic efficiency, oxidative damage, and stomatal conductance in the evergreen dwarf shrub Calluna vulgaris (L.). Hull was analyzed in a Mediterranean ecosystem characterized by intense geothermal activity. Among the higher plants present in the area, this species appears to be the sole to possess the ability to grow near the geothermal sources. The hot fluid springs strongly alter the environment in their proximity: the emitted water vapor, CO2, H2S, CH4, H3BO3, SO42-, and NH4+ partly condensate and precipitate to the soil, thus leading to its extreme acidification and nutrient depletion. Furthermore, the temperature starts to rise sharply just a few centimeters under the soil surface. Under this multiple stress, the individuals of C. vulgaris growing within a few meters from the springs showed lower photosystem II efficiency, higher oxidative damage to the biomembranes, and lower stomatal conductance than the individuals growing farther away. Drought and high air temperatures occurring in summer exacerbate these harsh conditions, but only the plants closer to the springs did undergo an acute, yet transient crisis, as shown by the analyzed parameters. These results suggest that the main factors of stress are related to the physical and chemical features of the soil, while the adverse climate conditions apparently are of secondary importance. The possible role of reduced stomatal conductivity in enhancing the resistance of C. vulgaris to this hostile environment is discussed

Ridefinizione biostratigrafica e geocronologica delle unità formazionali neogeniche della Sardegna centrale (Italia)

Recent, detailed geological and stratigraphic surveys of a large area of the Marmilla region (central Sardinia) have made it possible to reconsider the lithobiostratigraphic characteristics of the formal and informal units in the literature on the Cenozoic (Late Oligocene – Neogene) which have been in use up to now. Extension of the research to adjoining lands, including Alta Marmilla, Alto Oristanese, Sinis–Planargia, Barigadu, Baronie and Sarcidano, has also made it possible to perform an overall analysis of the entire Cenozoic basin of central Sardinia and, finally, to make significant comparisons with the coeval successions outcropping in southern and northern Sardinia. In this preliminary note we then report on new data concerning the biostratigraphic aspects of the successions considered, while eco-biostratigraphic data and the depositional and synthemic arrangement, now at an advanced stage of definition, will be discussed in a later, more complete work. Some units in the literature are once again proposed, albeit with amendments, as suggested by the new regulations governing the establishment of new formal depositional units and conservation of units in the literature, and with new geochronostratigraphic delimitations (e. g. the Gesturi Formation). Other units change their hierarchical rank (e. g. the Marmilla Group), while for others it was not deemed useful to keep them (e. g. Marne di Ales), since they might cause confusion. Most of the Formations, all of the Members and Groups are proposed in this work for the first time. The formation units outcropping in central Sardinia’s Cenozioc basin are represented for the most part by a sedimentary and volcano-sedimentary succession several hundreds of metres thick, the age of which is included within the Chattian-Aquitanian passage and the Plio-Quaternary. These are sediments from silicoclastics to mixed carbonatic-silicoclastics, in some cases richly fossiliferous, in which are inserted volcanic products from acid to intermediate-basic with a calcalkaline composition, the latter almost exclusively present starting from the Aquitanian up to the Late Burdigalian, with the strongest concentration in deposits of Burdigalian age. As is the case in northern and southern Sardinia, central Sardinia’s Miocene formations can be referred to three main sedimentary cycles recognized on the basis of heir litho-biostratigraphy and the analysis of associations of benthic macrofauna, which will be discussed in a specific article to be published shortly. The first Miocene sedimentary cycle evolved between the Chattian/Aquitanian limit and the Late Burdigalian (N6 Zone); the second cycle began in the Uppermost Burdigalian, in correspondence to the upper part of the Globigerinoides trilobus Zone (N7 Zone) and closes in the Late Serravallian (G. siakensis Zone, G. siakensis-G. obliqua obliqua Subzone); finally, after a clear regression phase, in the Tortonian (or perhaps already in the Uppermost Serravillian) the third cycle began and ended in the Early Messinian, in correspondence to the upper part of biostratigraphic N17a Zone. On the basis of a comparative analysis of autochthonous benthic associations, especially those with molluscs, and of the textural characteristics of the sediments, the prevalent depositional environment for the three cycles mentioned previously is that of a platform and secondly of a slope, but in some cases fluvio-lacustrine and deltaic. At the end of the third cycle there is a hiatus and/or erosion, or local continental sedimentation (Nuraghe Baboe Cabitza A n. Formation). A further marine sedimentary cycle locally (Sinis, Orosei) began and ends in the Lower Pliocene (Nuraghe Baboe Cabitza B n. Formation). In an overall biostratigraphic and geochronological frame, the comparison between the most important sedimentary, tectonic and volcanic occurrences in central Sardinia from the Oligocene to the Pliocene and those which occurred in the north and south of the island are pointed out. From the paleogeographic standpoint, the deposits of the first Miocene sedimentary cycle are part of the autochthonous cover of the southern European continental margin; those of the second and third cycles are instead connected with the aperture of the Balearic basin and the northern Tyrrhenian Sea; finally, the Early Pliocene marine succession is referred to the open of the southern Tyrrhenian basin, as well as the widespread volcanic activity of prevalently basaltic alkaline nature (the «Plio-Pleistocene volcanic cycle») towards the end of the Messinian and in the Pliocene

Brodifacoum Levels and Biomarkers in Coastal Fish Species following a Rodent Eradication in an Italian Marine Protected Area: Preliminary Results

Brodifacoum is the most common rodenticide used for the eradication of invasive rodents from islands. It blocks the vitamin K cycle, resulting in hemorrhages in target mammals. Non-target species may be incidentally exposed to brodifacoum, including marine species. A case study conducted on the Italian Marine Protected Area of Tavolara Island was reported after a rodent eradication using the aerial broadcast of a brodifacoum pellet. Brodifacoum presence and effects on non-target marine organisms were investigated. Different fish species were sampled, and a set of analyses was conducted to determine vitamin K and vitamin K epoxide reductase concentrations, prothrombin time, and erythrocytic nuclear abnormalities (ENA) assay. In all the examined organisms, brodifacoum was not detected. The results obtained showed differences in vitamin K and vitamin K epoxide concentrations among the samples studied, with a positive correlation for three species between vitamin K, vitamin K epoxide, and fish weight. The prothrombin time assay showed a good blood clotting capacity in the fish. Higher abnormality values were recorded for four species. The results of this study suggest that it is possible to hypothesize that the sampled fish were not likely to have been exposed to brodifacoum and that consequently there are no negative issues concerning human consumption

Inter-population variations in concentrations, determinants of and correlations between 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE): a cross-sectional study of 3161 men and women from Inuit and European populations.

The study is part of a collaborative project (Inuendo), aiming to assess the impact of dietary persistent organochlorine pollutants (POPs) on human fertility. The aims with the present study are to analyze inter-population variations in serum concentrations of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE), to assess inter-population variations in biomarker correlations, and to evaluate the relative impact of different determinants for the inter-individual variations in POP-biomarkers. CB-153 concentrations were much higher in Inuits and Swedish fishermen's populations than in the populations from Eastern Europe, whereas the pattern was different for p,p'-DDE showing highest concentrations in the Kharkiv population. The correlations between the POP-biomarkers varied considerably between the populations, underlining that exposure sources differ and that the choice of representative biomarkers of overall POP exposure has to be based on an analysis of the specific exposure situation for each population. Age and gender were consistent determinants of serum POPs; seafood was of importance only in the Inuit and Swedish populations

Fertility in four regions spanning large contrasts in serum levels of widespread persistent organochlorines: a cross-sectional study.

BACKGROUND: Persistent organochlorine pollutants (POPs) may interfere with reproductive function but direct evidence in humans is very limited. METHODS: Fertility was examined in four regions with contrasting blood levels of POPs. Pregnant women and their partners in Warsaw (Poland), Kharkiv (Ukraine) and Greenland were consecutively enrolled during antenatal visits. Swedish fishermen and their spouses were recruited separately and independently of current pregnancy. Lipid adjusted serum concentrations of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (DDE) were available for both partners. Time to pregnancy interviews were obtained among 2269 women and 798 men provided a semen sample. RESULTS: Inuits had high levels of both POP markers, Swedish fishermen were high in CB-153 but low in DDE, men from Kharkiv were high in DDE and low in CB-153 while men from Warsaw were low in CB-153 and had intermediate DDE levels. Compared to Warsaw couples, fecundability was reduced among couples from Kharkiv [adjusted fecundability ratio (FR) 0.64 (95% CI 0.5-0.8)] and elevated in Swedish fishermen families [FR 1.26 (95% CI 1.0-1.6)]. Adjusted geometric means of sperm counts and morphology did not differ between regions while sperm motility was higher in men living in Warsaw. CONCLUSION: We observed regional differences in time to pregnancy and sperm motility that may be related to regional differences in POP blood levels, but other interpretations are also plausible. In particular, differences in access to safe contraception and in the prevalence of contraceptive failures are most likely to bias comparisons of time to pregnancy

Fertility in four regions spanning large contrasts in serum levels of widespread persistent organochlorines: a cross-sectional study

BACKGROUND: Persistent organochlorine pollutants (POPs) may interfere with reproductive function but direct evidence in humans is very limited. METHODS: Fertility was examined in four regions with contrasting blood levels of POPs. Pregnant women and their partners in Warsaw (Poland), Kharkiv (Ukraine) and Greenland were consecutively enrolled during antenatal visits. Swedish fishermen and their spouses were recruited separately and independently of current pregnancy. Lipid adjusted serum concentrations of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (DDE) were available for both partners. Time to pregnancy interviews were obtained among 2269 women and 798 men provided a semen sample. RESULTS: Inuits had high levels of both POP markers, Swedish fishermen were high in CB-153 but low in DDE, men from Kharkiv were high in DDE and low in CB-153 while men from Warsaw were low in CB-153 and had intermediate DDE levels. Compared to Warsaw couples, fecundability was reduced among couples from Kharkiv [adjusted fecundability ratio (FR) 0.64 (95% CI 0.5-0.8)] and elevated in Swedish fishermen families [FR 1.26 (95% CI 1.0-1.6)]. Adjusted geometric means of sperm counts and morphology did not differ between regions while sperm motility was higher in men living in Warsaw. CONCLUSION: We observed regional differences in time to pregnancy and sperm motility that may be related to regional differences in POP blood levels, but other interpretations are also plausible. In particular, differences in access to safe contraception and in the prevalence of contraceptive failures are most likely to bias comparisons of time to pregnancy

Impact of PCB and p,p'-DDE contaminants on human sperm Y : X chromosome ratio: Studies in three European populations and the inuit population in Greenland

Recent studies indicate that persistent organohalogen pollutants (POPs) may contribute to sex ratio changes in offspring of exposed populations. Our aim in the present study was to investigate whether exposure to 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153) and dichlorodiphenyldichloroethene (pp'-DDE) affects sperm Y:X chromosome distribution. SUBJECTS AND METHODS: We obtained semen and blood for analysis of PCB-153 and pp'-DDE levels from 547 men from Sweden, Greenland, Poland (Warsaw), and Ukraine (Kharkiv), with regionally different levels of POP exposure. The proportion of Y- and X-chromosome-bearing sperm in the semen samples was determined by two-color fluorescence in situ hybridization analysis. RESULTS: Swedish and Greenlandic men had on average significantly higher proportions of Y sperm (in both cohorts, 51.2%) and correspondingly higher lipid-adjusted concentrations of PCB-153 (260 ng/g and 350 ng/g, respectively) compared with men from Warsaw (50.3% and 22 ng/g) and Kharkiv (50.7% and 54 ng/g). In the Swedish cohort, log-transformed PCB- 153 and log-transformed pp'-DDE variables were significantly positively associated with Y-chromosome fractions (p-values 0.04 and < 0.001, respectively). On the contrary, in the Polish cohort PCB-153 correlated negatively with the proportion of Y-bearing fraction of spermatozoa (p = 0.008). CONCLUSIONS: The present study indicates that POP exposure might be involved in changing the proportion of ejaculated Y-bearing spermatozoa in human populations. Intercountry differences, with different exposure situations and doses, may contribute to varying Y:X chromosome ratios