The influence of weathering process on geotechnical and mineralogical properties of fine grained lithological flysch components along the northern Adriatic coast of Croatia

2019 ◽  
Author(s):  
Martina Vivoda Prodan
Keyword(s):  
Northern Adriatic ◽  
Fine Grained ◽  
Mineralogical Properties ◽  
Adriatic Coast ◽  
Weathering Process

Climatology and process-oriented analysis of the Adriatic sea-level extremes

2021 ◽  
Author(s):  
Jadranka Sepic ◽  
Mira Pasaric ◽  
Iva Medugorac ◽  
Ivica Vilibic ◽  
Maja Karlovic ◽  
...  
Keyword(s):  
Time Series ◽  
Sea Level ◽  
Adriatic Sea ◽  
The South ◽  
Northern Adriatic ◽  
Atmospheric Waves ◽  
Tidal Forcing ◽  
Atmospheric Processes ◽  
South Eastern ◽  
Adriatic Coast

<p>The northern and the eastern coast of the Adriatic Sea are occasionally affected by extreme sea-levels known to cause substantial material damage. These extremes appear due to the superposition of several ocean processes that occur at different periods, have different spatial extents, and are caused by distinct forcing mechanisms.</p><p>To better understand the extremes, hourly sea-level time series from six tide-gauge stations located along the northern and the eastern Adriatic coast (Venice, Trieste, Rovinj, Bakar, Split, Dubrovnik) were collected for the period of 1956 to 2015 (1984 to 2015 for Venice) and analysed. The time series have been checked for spurious data, and then decomposed using tidal analysis and filtering procedures. The following time series were thus obtained for each station: (1) trend; (2) seasonal signal; (3) tides; (4-7) sea-level oscillations at periods: (4) longer than 100 days, (5) from 10 to 100 days, (6) from 6 hours to 10 days, and (7) shorter than 6 hours. These bands correspond, respectively, to sea-level fluctuations dominantly forced by (but not restricted to): (1) climate change and land uplift and sinking; (2) seasonal changes; (3) tidal forcing; (4); quasi-stationary atmospheric and ocean circulation and climate variability patterns; (5) planetary atmospheric waves; (6) synoptic atmospheric processes; and (7) mesoscale atmospheric processes.</p><p>Positive sea-level extremes surpassing 99.95 and 99.99 percentile values, and negative sea-level extremes lower than 0.05 and 0.01 percentile values were extracted from the original time series for each station. It was shown that positive (negative) extremes are up to 50-100% higher (lower) in the northern than in the south-eastern Adriatic. Then, station-based distributions, return periods, seasonal distributions, event durations, and trends were estimated and assessed. It was shown that the northern Adriatic positive sea-level extremes are dominantly caused by synoptic atmospheric processes superimposed to positive tide (contributing jointly to ~70% of total extreme height), whereas more to the south-east, positive extremes are caused by planetary atmospheric waves, synoptic atmospheric processes, and tides (each contributing with an average of ~25%). As for the negative sea-level extremes, these are due to a combination of planetary atmospheric waves and tides: in the northern Adriatic tide provides the largest contribution (~60%) while in the south-eastern Adriatic the two processes are of similar impact (each contributing with an average of ~30%). The simultaneity of the events along the entire northern and eastern Adriatic coast was studied as well, revealing that positive extremes are strongly regional dependant, i.e. that they usually appear simultaneously only along one part of the coast, whereas negative extremes are more likely to appear along the entire coast at the same time.</p><p>Finally, it is suggested that the distribution of sea-level extremes along the south-eastern Adriatic coast can be explained as a superposition of tidal forcing and prevailing atmospheric processes, whereas for the northern Adriatic, strong topographic enhancement of sea-level extremes is also important.</p>

Geochemical and mineralogical properties of sulfide-bearing fine-grained sediments in Finland

1998 ◽  
Vol 36 (1-2) ◽  
pp. 37-44 ◽  
Author(s):  
H. Deng ◽  
M. Åström ◽  
A. Björklund
Keyword(s):  
Fine Grained ◽  
Mineralogical Properties

scholarly journals RIGED-RA project - Restoration and management of Coastal Dunes in the Northern Adriatic Coast, Ravenna Area - Italy

2016 ◽  
Vol 44 ◽  
pp. 052038 ◽  
Author(s):  
Beatrice M.S. Giambastiani ◽  
Nicolas Greggio ◽  
Flavia Sistilli ◽  
Stefano Fabbri ◽  
Frederico Scarelli ◽  
...  
Keyword(s):  
Coastal Dunes ◽  
Northern Adriatic ◽  
Adriatic Coast

scholarly journals Paesaggi sommersi in Alto Adriatico Dalla pianura glaciale al futuro innalzamento marino

2021 ◽  
Author(s):  
Alessandro Fontana ◽  
Livio Ronchi
Keyword(s):  
Sea Level ◽  
Late Quaternary ◽  
Significant Risk ◽  
Anthropogenic Activity ◽  
Northern Adriatic Sea ◽  
Northern Adriatic ◽  
Large Sector ◽  
Adriatic Coast ◽  
The Last Glacial Maximum ◽  
North Western

The Northern Adriatic Sea is characterized by a gentle marine shelf that led this area and the surroundings coastal plains to be very sensitive even to limited variations of sea level during the Late Quaternary. These changes affected directly and indirectly the ancient human communities. In particular, around 19 ka cal BP, the end of the Last Glacial Maximum (LGM) triggered a rapid marine transgression which drowned a large sector of the alluvial plain formerly existing on the present seabed. This dramatic transformation was accompanied by significant changes in the hydrographic network and in the channel morphology of the major rivers. Around 5500 BC the Adriatic coast was already rather comparable to the present one and the rate of sea-level rise considerably lowered. Since that time the paleogeographic changes occurred along the coast were mainly constrained by the complex interplay between eustatic variations, fluvial inputs and subsidence. In the last centuries the anthropogenic activity has strongly increased its influence on the coastal dynamics and the effects of the ongoing global warming are exposing to significant risk of submersion the low-lying coasts of north-western Adriatic.

scholarly journals Multianalysis Characterization of Mineralogical Properties of Copper-Lead-Zinc Mixed Ores and Implications for Comprehensive Recovery

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Qian Zhang ◽  
Shuming Wen ◽  
Qicheng Feng ◽  
Song Zhang ◽  
Wenlin Nie
Keyword(s):  
Mineral Resources ◽  
Fine Grained ◽  
Integrated Technology ◽  
Oxidation Rates ◽  
Mineralogical Properties ◽  
Lead And Zinc ◽  
New Ideas ◽  
Lead Zinc ◽  
Comprehensive Recovery ◽  
Copper Lead

Copper-lead-zinc mixed ore in Tibet, China, is a complex and refractory polymetallic ore resource; thus, ascertaining its mineralogical properties is very important for comprehensive recovery of valuable elements. In this work, the mineralogical properties of this copper-lead-zinc mixed ore have been characterized in detail following a multidisciplinary approach, including chemical, phase, x-ray diffraction (XRD), electron microprobe, and mineral liberation analyses. The results show that the raw ore contained 0.53% Cu, 1.29% Pb, and 0.54% Zn; the oxidation rates of copper, lead, and zinc were 40.21%, 79.31%, and 84.83%, respectively. The Au and Ag contents in the raw ore were 0.28 g/t and 23.6 g/t, which can be comprehensively utilized along with the recovery of copper, lead, and zinc. The gangue mainly contained SiO2, CaO, and Al2O3. Copper in the raw ore mainly existed in bornite, duftite, chalcopyrite, and chrysocolla; lead mainly existed in cerussite, duftite, and galena; zinc mainly existed in willemite, hemimorphite, and sphalerite. The complexity in the embedding and wrapping relationships, fine-grained dissemination, high oxidation, and considerable differences in the floatability of various minerals result in difficulties in recovering the target minerals using a single method. Based on the systematic mineralogical properties obtained, an integrated technology of “bulk flotation-oxidation roasting-hydrometallurgy” has been proposed to enrich and separate copper, lead, and zinc in the ore, providing new ideas for the comprehensive and efficient utilization of polymetallic mineral resources in Tibet.

scholarly journals Freezing–Thawing Behavior of Lime Treated Fine–grained Soil

2018 ◽  
Vol 7 (4) ◽  
pp. 75
Author(s):  
Abdulrahman Aldaood ◽  
Amina Khalil ◽  
Marwen Bouasker ◽  
Muzahim Al-Mukhtar
Keyword(s):  
Compressive Strength ◽  
Water Content ◽  
Unconfined Compressive Strength ◽  
Soil Samples ◽  
Treated Soil ◽  
Freeze Thaw ◽  
Fine Grained ◽  
Mineralogical Properties ◽  
Fine Grained Soil ◽  
The Impact

This research study was carried out to investigate the impact of freeze-thaw cycles on the mechanical and the mineralogical properties of lime treated fine-grained soil. The unconfined compressive strength, wave velocity, volume change, water content, pH and electrical conductivity values were determined during freeze-thaw cycles. Furthermore, Mercury porosimetry and X-ray diffraction tests were carry out to determine changes at microscopic level. The soil used in this study was taken at a site near Jossigny region in eastern part of Paris–France. The soil samples were treated with optimum lime percent 3% depending on the pH method, then cured for 28 days at 20 °C. The soil samples were subjected to 12 cycles of freeze-thaw following ASTM procedure.    The result referred that, natural soil exhibit no strength resistance against freeze-thaw cycles and failed during the first hours of freeze-thaw cycles. Analyses indicated that freeze-thaw cycles reduce the unconfined compressive strength of all the tested samples. Moreover, water content during the applied cycles increases and induces significant volume changes. During freeze-thaw cycles, the cracks propagation which caused by the formation of ice lenses in the pores of lime treated soil samples were consider to have significant. The changes in the micro-structural and mineralogical properties reduce the durability  of the lime treated soil samples when subjected to freeze-thaw cycles.

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