Chemical and physical dynamics of marine pockmarks with insights into the organic carbon cycling on the Malin Shelf and in Dunmanus Bay, Ireland.

Pockmarks are specific type of marine geological setting resembling craters or pits. They are considered surface expression of fluid flow in the marine subsurface. Pockmarks are widespread in the aquatic environment but the understanding of their formation mechanisms, relationship with marine macro- and micro-biota and their geochemistry remains limited. Despite numerous findings of these features in Irish waters they received little attention and remain poorly studied. In this work extensive geophysical data sets collected by the Irish National Seabed Survey and its successor the INFOMAR project as well in situ sediment samples were utilized to provide baseline information on the nature of some of these features, the processes they are fuelled by and their geochemical characteristics. Pockmarks from open shelf (Malin Shelf) and bay, fjord like environment (Dunmanus Bay) are compared and theories of their formation are formulated. Sediment from these features was extensively studied utilizing advanced geotechnical and geochemical tools to describe and quantify processes taking place in the subsurface. Organic matter was characterized on a molecular level by combined biomarker and advanced Nuclear Magnetic Resonance approach

EVOLUTION OF THE SUBCONTINENTAL LITHOSPHERE DURING MESOZOIC TETHYAN RIFTING: CONSTRAINTS FROM THE EXTERNAL LIGURIAN MANTLE SECTION (NORTHERN APENNINE, ITALY)

Our study is focussed on mantle bodies from the External Ligurian ophiolites, within the Monte Gavi and Monte Sant'Agostino areas. Here, two distinct pyroxenite-bearing mantle sections were recognized, mainly based on their plagioclase-facies evolution. The Monte Gavi mantle section is nearly undeformed and records reactive melt infiltration under plagioclase-facies conditions. This process involved both peridotites (clinopyroxene-poor lherzolites) and enclosed spinel pyroxenite layers, and occurred at 0.7–0.8 GPa. In the Monte Gavi peridotites and pyroxenites, the spinel-facies clinopyroxene was replaced by Ca-rich plagioclase and new orthopyroxene, typically associated with secondary clinopyroxene. The reactive melt migration caused increase of TiO2 contents in relict clinopyroxene and spinel, with the latter also recording a Cr2O3 increase. In the Monte Gavi peridotites and pyroxenites, geothermometers based on slowly diffusing elements (REE and Y) record high temperature conditions (1200-1250 °C) related to the melt infiltration event, followed by subsolidus cooling until ca. 900°C. The Monte Sant'Agostino mantle section is characterized by widespread ductile shearing with no evidence of melt infiltration. The deformation recorded by the Monte Sant'Agostino peridotites (clinopyroxene-rich lherzolites) occurred at 750–800 °C and 0.3–0.6 GPa, leading to protomylonitic to ultramylonitic textures with extreme grain size reduction (10–50 μm). Compared to the peridotites, the enclosed pyroxenite layers gave higher temperature-pressure estimates for the plagioclase-facies re-equilibration (870–930 °C and 0.8–0.9 GPa). We propose that the earlier plagioclase crystallization in the pyroxenites enhanced strain localization and formation of mylonite shear zones in the entire mantle section. We subdivide the subcontinental mantle section from the External Ligurian ophiolites into three distinct domains, developed in response to the rifting evolution that ultimately formed a Middle Jurassic ocean-continent transition: (1) a spinel tectonite domain, characterized by subsolidus static formation of plagioclase, i.e. the Suvero mantle section (Hidas et al., 2020), (2) a plagioclase mylonite domain experiencing melt-absent deformation and (3) a nearly undeformed domain that underwent reactive melt infiltration under plagioclase-facies conditions, exemplified by the the Monte Sant'Agostino and the Monte Gavi mantle sections, respectively. We relate mantle domains (1) and (2) to a rifting-driven uplift in the late Triassic accommodated by large-scale shear zones consisting of anhydrous plagioclase mylonites. Hidas K., Borghini G., Tommasi A., Zanetti A. & Rampone E. 2021. Interplay between melt infiltration and deformation in the deep lithospheric mantle (External Liguride ophiolite, North Italy). Lithos 380-381, 105855

Impact of geogenic degassing on C-isotopic composition of dissolved carbon in karst systems of Greece

The Earth C-cycle is complex, where endogenic and exogenic sources are interconnected, operating in a multiple spatial and temporal scale (Lee et al., 2019). Non-volcanic CO2 degassing from active tectonic structures is one of the less defined components of this cycle (Frondini et al., 2019). Carbon mass-balance (Chiodini et al., 2000) is a useful tool to quantify the geogenic carbon output from regional karst hydrosystems. This approach has been demonstrated for central Italy and may be valid also for Greece, due to the similar geodynamic settings. Deep degassing in Greece has been ascertained mainly at hydrothermal and volcanic areas, but the impact of geogenic CO2 released by active tectonic areas has not yet been quantified. The main aim of this research is to investigate the possible deep degassing through the big karst aquifers of Greece. Since 2016, 156 karst springs were sampled along most of the Greek territory. To discriminate the sources of carbon, the analysis of the isotopic composition of carbon was carried out. δ13CTDIC values vary from -16.61 to -0.91‰ and can be subdivided into two groups characterized by (a) low δ13CTDIC, and (b) intermediate to high δ13CTDIC with a threshold value of -6.55‰. The composition of the first group can be related to the mixing of organic-derived CO2 and the dissolution of marine carbonates. Springs of the second group, mostly located close to Quaternary volcanic areas, are linked to possible carbon input from deep sources

Impact of Etna’s volcanic emission on major ions and trace elements composition of the atmospheric deposition

Mt. Etna, on the eastern coast of Sicily (Italy), is one of the most active volcanoes on the planet and it is widely recognized as a big source of volcanic gases (e.g., CO2 and SO2), halogens, and a lot of trace elements, to the atmosphere in the Mediterranean region. Especially during eruptive periods, Etna’s emissions can be dispersed over long distances and cover wide areas. A group of trace elements has been recently brought to attention for their possible environmental and human health impacts, the Technology-critical elements. The current knowledge about their geochemical cycles is still scarce, nevertheless, recent studies (Brugnone et al., 2020) evidenced a contribution from the volcanic activity for some of them (Te, Tl, and REE). In 2021, in the framework of the research project “Pianeta Dinamico”, by INGV, a network of 10 bulk collectors was implemented to collect, monthly, atmospheric deposition samples. Four of these collectors are located on the flanks of Mt. Etna, other two are in the urban area of Catania and three are in the industrial area of Priolo, all most of the time downwind of the main craters. The last one, close to Cesarò (Nebrodi Regional Park), represents the regional background. The research aims to produce a database on major ions and trace element compositions of the bulk deposition and here we report the values of the main physical-chemical parameters and the deposition fluxes of major ions and trace elements from the first year of research. The pH ranged from 3.1 to 7.7, with a mean value of 5.6, in samples from the Etna area, while it ranged between 5.2 and 7.6, with a mean value of 6.4, in samples from the other study areas. The EC showed values ranging from 5 to 1032 μS cm-1, with a mean value of 65 μS cm-1. The most abundant ions were Cl- and SO42- for anions, Na+ and Ca+ for cations, whose mean deposition fluxes, considering all sampling sites, were 16.6, 6.8, 8.4, and 6.0 mg m-2 d, respectively. The highest deposition fluxes of volcanic refractory elements, such as Al, Fe, and Ti, were measured in the Etna’s sites, with mean values of 948, 464, and 34.3 μg m-2 d-1, respectively, higher than those detected in the other sampling sites, further away from the volcanic source (26.2, 12.4, 0.5 μg m-2 d-1, respectively). The same trend was also observed for volatile elements of prevailing volcanic origin, such as Tl (0.49 μg m-2 d-1), Te (0.07 μg m-2 d-1), As (0.95 μg m-2 d-1), Se (1.92 μg m-2 d-1), and Cd (0.39 μg m-2 d-1). Our preliminary results show that, close to a volcanic area, volcanic emissions must be considered among the major contributors of ions and trace elements to the atmosphere. Their deposition may significantly impact the pedosphere, hydrosphere, and biosphere and directly or indirectly human health

The Geology of Kuwait

This open access book contains a set of chapters covering all aspects of geosciences related to Kuwait and adjacent regions, including Iran, Saudi Arabia and the Arab Gulf states. It covers basic information about the geology including a wide range of geoscientific disciplines such as marine geology, structural geology, hydrogeology and geophysics related to the region. This book is aimed at researchers and students, as well as professionals in the field of hazard mitigation and petroleum exploration

Understanding the marine environment : seabed habitat investigations of the Dogger Bank offshore draft SAC

This report details work carried out by the Centre for Environment, Fisheries and Aquaculture Science (Cefas), British Geological Surveys (BGS) and Envision Ltd. for the Joint Nature Conservation Committee (JNCC). It has been produced to provide the JNCC with evidence on the distribution and extent of Annex I habitat (including variations of these features) on the Dogger Bank in advance of its possible designation as a Special Area of Conservation (SAC). The report contains information required under Regulation 7 of the Conservation (Natural Habitats, &c.) Regulations 2007 and will enable the JNCC to advise the Department for Environment, Food and Rural Affairs (Defra) as to whether the site is deemed eligible as a SAC. The report provides detailed information about the Dogger Bank and evaluates its features of interest according to the Habitats Directive selection criteria and guiding principles. This assessment has been made following a thorough analysis of existing information combined with newly acquired field survey data collected using ‘state of the art’ equipment. In support of this process acoustic (sidescan sonar and multibeam echosounder) and groundtruthing data (Hamon grabs, trawls and underwater video) were collected during a 19-day cruise on RV Cefas Endeavour, which took place between 2-20 April 2008. Existing information and newly acquired data were combined to investigate the sub-surface geology, surface sediments and bedforms, epifaunal and infaunal communities of the Dogger Bank. Results were integrated into a habitat map employing the EUNIS classification. Key results are as follows: • The upper Pleistocene Dogger Bank Formation dictates the shape of the Dogger Bank. • The Dogger Bank is morphologically distinguishable from the surrounding seafloor following the application of a technique, which differentiates the degree of slope. • A sheet of Holocene sediments of variable thickness overlies the Dogger Bank Formation. At the seabed surface, these Holocene sediments can be broadly delineated into fine sands and coarse sediments. • Epifaunal and infaunal communities were distinguished based on multivariate analysis of data derived from video and stills analysis and Hamon grab samples. Sediment properties and depth were the main factors controlling the distribution of infauna and epifauna across the Bank. • Epifaunal and infaunal community links were explored. Most stations could be categorised according to one of four combined infaunal/epifaunal community types (i.e. sandy sediment bank community, shallow sandy sediment bank community, coarse sediment bank community or deep community north of the bank). • Biological zones were identified using modelling techniques based on light climate and wave base data. Three biological zones, namely infralittoral, circalittoral and deep circalittoral are present in the study site. • EUNIS level 4 habitats were mapped by integrating acoustic, biological, physical and optical data. Eight different habitats are present on the Dogger Bank. This report also provides some of the necessary information and data to help the JNCC ultimately reach a judgement as to whether the Dogger Bank is suitable as an SAC. In support of this process the encountered habitats and the ecology of the Dogger Bank are compared with other SACs known to contain sandbank habitats in UK waters. The functional and ecological importance of the Dogger Bank as well as potential anthropogenic impacts is discussed. A scientific justification underlying the proposed Dogger Bank dSAC boundary is also given (Appendix 1). This is followed by a discussion of the suitability and cost-effectiveness of techniques utilised for seabed investigations of the Dogger Bank. Finally, recommendations for strategies and techniques employed for investigation of Annex I sandbanks are provided

Biodiversity Databases

Computing and database management has shifted from cottage industry-style methods — the small independent researcher keeping records for a particular project — to state-of-the-art file storage systems, presentation, and distribution over the Internet. New and emerging techniques for recognition, compilation, and data management have made managing data a discipline in its own right. Covering all aspects of this data management, Biodiversity Databases: Techniques, Politics, and Applications brings together input from social scientists, programmers, database designers, and information specialists to delineate the political setting and give institutions platforms for the dissemination of taxonomic information. A practical and logical guide to complex issues, the book explores the changes and challenges of the information age. It discusses projects developed to provide better access to all available biodiversity information. The chapters make the case for the need for representation of concepts in taxonomic databases. They explore issues involved in connecting databases with different user interfaces, the technical demands of linking databases that are not entirely uniform in structure, and the problems of user access and the control of data quality. The book highlights different approaches to addressing concerns associated with the taxonomic impediment and the low reproducibility of taxonomic data. It provides an in-depth examination of the challenge of making taxonomic information more widely available to users in the wider scientific community, in government, and the general population