Search results for "Sediment"
showing 10 items of 1648 documents
Carbon-isotope record and palaeoenvironmental changes during the early Toarcian oceanic anoxic event in shallow-marine carbonates of the Adriatic Car…
2013
AbstractGeochemical (δ13C, δ18O and Mn) compositions of Lower Jurassic shallow-water carbonates cropping out in Croatia were analyzed to elucidate the impact of the early Toarcian oceanic anoxic event (T-OAE) on the Adriatic Carbonate Platform (AdCP). The bulk-rock carbon-isotope records through the studied sections (Velebit-A, Velebit-B and Gornje Jelenje) are characterized by two significant excursions: (i) an initial positive trend interrupted by a pronounced negative shift (c. 2.5‰) that is followed by (ii) an increasing trend of positive values (up to 4.5‰). A comparison with δ13C trends obtained from well-calibrated sections from other localities in Europe shows that the overall chara…
Seismic expression of the shallow structure of The Neapolitan Yellow Tuff (NYT) caldera offshore the Campi Flegrei
2014
In this study we integrate high-resolution swath bathymetry, single-channel reflection seismic data and gravity core data, to provide new insights into the shallow structure and latest Quaternary to Holocene evolution of the submerged sector of the Neapolitan Yellow Tuff (NYT) caldera (Campi Flegrei) in the Pozzuoli Bay. The new data allow for a reconstruction of the offshore geometry of the NYT caldera collapse – ring fault system, along with the style and timing of deformation of the inner caldera resurgence. Our interpretation shows that the NYT eruption (~15 ka BP) was associated with a caldera collapse bounded by an inward-dipping ring fault system. The ring fault system consists in a …
The Neapolitan Yellow Tuff caldera offshore the Campi Flegrei: Stratal architecture and kinematic reconstruction during the last 15 ky
2014
In this study we integrate high-resolution swath bathymetry, single channel reflection seismic data and gravity core data, to provide new insights into the shallow structure and latest Quaternary to Holocene evolution of the submerged sector of the Neapolitan Yellow Tuff (NYT) caldera (Campi Flegrei) in the Pozzuoli Bay. The new data allow for a reconstruction of the offshore geometry of the NYT caldera collapse-ring fault system, along with the style and timing of deformation of the inner caldera resurgence.Our interpretation shows that the NYT eruption (~. 15. ka BP) was associated with a caldera collapse bounded by an inward-dipping ring fault system. The ring fault system consists in a …
Eksperimentāla modeļa izstrāde neisseria gonorrhoeae antibakteriālas rezistences noteikšnai
2019
Neisseria gonorrhoeae infekcija mūsdienās ir globāla problēma. Latvijā tā ir otrā visbiežāk izplatītā bakteriālā seksuāli transmisīvā slimība. Mūsdienās satraucošā N. gonorrhoeae rezistence pret antibiotikām tiek atzīmēta visā pasaulē, tā ir padarījusi ārstēšanu nekomplicētai gonokoku infekcijai vēl sarežģītāku, ar mazāk ārstēšanas iespējām nekā agrāk. Visu laiku ārstiem pastāv jautājums, kā efektīvāk un ar maksimālu precizitāti noteikt antibakteriālo rezistenci. Tehnoloģijas nepārtraukti attīstās, tāpēc, teorētiski, pētījumi ar silīcija dioksīda mirkodaļiņām un to mijiedarbību ar mikroorganismiem varētu būt nozīmīgi antibakteriālās rezistences noteikšanai. Darba mērķis: Eksperimentāli note…
Submarine canyon morphologies in the Gulf of Palermo (Southern Tyrrhenian Sea) and possible implications for geo-hazard
2011
12 pages, 12 figures, 1 table.
Submarine Mass Movements Along a Sediment Starved Margin: The Menorca Channel (Balearic Islands - Western Mediterranean)
2014
6th International Symposium on Submarine Mass Movements and Their Consequences (ISSMMTC), 23-25 September 2013, Kiel, Germany.-- 10 pages, 5 figures
Submarine canyons of north-western Sicily (Southern Tyrrhenian Sea): Variability in morphology, sedimentary processes and evolution on a tectonically…
2014
Special issue Submarine Canyons: Complex Deep-Sea Environments Unravelled by Multidisciplinary Research.-- 13 pages, 11 figures, 2 tables
Potential Cyclic Steps in a Gully System of the Gulf of Palermo (Southern Tyrrhenian Sea)
2016
Multibeam bathymetric data revealed the occurrence of atrain of bedforms along a gully system in the Gulf of Palermo, Southern Tyrrhenian Sea. The observed gullies, located in the westernmost sector of the Gulf of Palermo, incise the outer shelf at a depth of 120 m and converge at the Zafferano Canyon, connecting to the Palermo Basin at a the depth of 1300 m. Bedforms develop along these gullies and along the thalweg of the canyon, displaying an average wavelength of 200 m, with maximum values of 340 m. Their gully floor location combined with their wave length, upslope asymmetry and crescent shape point to a possible cyclic steporigin of these bedforms. Preliminary numerical modeling sugge…
Oxygen isotopes in single micrometer-sized quartz grains: tracing the source of Saharan dust over long-distance atmospheric transport
2002
Abstract Oxygen isotope compositions were measured by ion microprobe in individual micrometer-sized quartz grains extracted from one aerosol sample collected on the Cape Verde Islands and from four surface samples (three soils and one sediment) representing potential source regions of aerosols in Western and Central Africa (Morocco, Algeria, Niger, and Chad). A large range of δ18O values, from +6.2‰ to +39.3‰ is present within the aerosol quartz grains. The different size fractions of the quartz grains from the surface samples overlap nearly entirely this range but show significant differences in their δ18O distributions for the different size fractions of the grains (i.e., different modes,…
Microtomographic Quantification of Hydraulic Clay Mineral Displacement Effects During a CO2 Sequestration Experiment with Saline Aquifer Sandstone
2013
We combined a noninvasive tomographic imaging technique with an invasive open-system core-flooding experiment and compared the results of the pre- and postflooded states of an experimental sandstone core sample from an ongoing field trial for carbon dioxide geosequestration. For the experiment, a rock core sample of 80 mL volume was taken from the 629 m Stuttgart Formation storage domain of a saline sandstone aquifer at the CCS research pilot plant Ketzin, Germany. Supercritical carbon dioxide and synthetical brine were injected under in situ reservoir p/T-conditions at an average flow rate of 0.1 mL/min for 256 h. X-ray computed microtomographic imaging was carried out before and after the…