Antonio Brambati

Mercury contamination of coastal sediments as the result of long-term cinnabar mining activity (Gulf of Trieste, northern Adriatic sea) ☆

Abstract The Isonzo river mouth has been the source of Hg in the Gulf of Trieste (northern Adriatic sea) since the sixteenth century, making this shallow basin one of the most contaminated marine areas in the length of time and amount of metal accumulated. The occurrence and behaviour of total Hg (range 0.064–30.38 μg g −1 ; average 5.04 μg g −1 ; median 3.10 μg g −1 , n =80) and related size fractions in sediments of this coastal area were investigated in detail. The relationship between total Hg and the fine silt-clay ( 210 Pb dated core, collected in the central part of the Gulf, was also compared to other heavy metals (Fe, Cr, Cu, Mn, Ni and Zn). A preliminary estimate of Hg enrichment shows that the first 50 cm of sediment in the central sector of the Gulf of Trieste are noticeably contaminated, reaching a maximum of up to 25-fold above the proposed natural regional background of 0.17 μg g −1 . The vertical trend is well correlated to historical data of Hg extraction activity at the Idrija mine.

Grain size, mineralogy and geochemistry in Late Quaternary sediments from the Western Ross Sea outer slope as proxies for climate changes.

Textural, mineralogical and geochemical investigations of three sedimentary sequences from the Ross Sea continental slope allow to give some important indications on climatic and environmental changes occurred during the Late Quaternary. The cores show cyclical changes in several proxies (grain size, mineralogical and geochemical parameters) which are in phase with glacial/interglacial changes (MIS 1–8). Such fluctuations are supposed to be driven by changes in transport mechanisms, reworking and provenance of the material, as well as by changes in direction and strength of marine currents induced by variations in the ice coverage.

Geomorphology map of the marine and transitional terraces and raised shorelines of the Península Juan Mazía, Tierra Del Fuego. Straits of Magellan – Chile

This manuscript presents a detailed map (1:50,000) of the geomorphology of the marine and transitional terraces and raised shorelines linked to Holocene-Pleistocene (?) glacio-eustatic variations in Península Juan Mazía situated on the Segunda Angostura in the western area of the Straits of Magellan. The Main Map, centered on approximately 52° 40’ and 52°60’, was compiled through geomorphological survey in the field integrated with interpretation of aerial photographs and remote-sensing imagery. The survey has allowed mapping of a regular sequence of terraces and raised shorelines represented mainly by marine, and partially by transitional terraced deposits, located in four orders at the respective elevations of 18÷25 m, 6÷11 m, 3÷5 m and 1÷2 m above mean sea level. The Main Map also provides other features such as landforms and deposits, due to littoral, running water, glacial and wind processes.

Palaeoproductivity in the Ross Sea, Antarctica, during the last 15 kyr BP and its link with ice-core temperature proxies

Abstract A detailed study of organic carbon content obtained from two sediment cores collected in the Joides basin, western Ross Sea, Antarctica, was carried out. The variations observed during the last deglaciation and the Holocene were compared to the high-resolution climatic records (EPICA DC and Taylor Dome) preserved in the ice. The importance of the carbon content as a proxy for palaeoclimatic and palaeoenvironmental changes was investigated. A dramatic decrease in the Ross Sea palaeoproductivity was observed during the Antarctic Cold Reversal (12.5–14 kyr BP). Another decrease in total organic carbon in the second half of the Holocene (after 5–6 kyr BP) confirms the climate worsening observed in previous studies.

Geomorphology of marine and transitional terraces and raised shorelines between Punta Paulo and Porvenir, Tierra del Fuego, Straits of Magellan – Chile

ABSTRACT This paper presents a coastal geomorphology map of some of the Chilean region of the Straits of Magellan, and is based on a combined geomorphological and sedimentological approach applicable to a larger section of the coast. The mapped area is located in Tierra del Fuego between the Segunda Angostura of the Straits of Magellan and Bahía Inútil. A detailed geomorphological map was compiled at a scale of 1:50,000, describing a sequence of 4 marine and transitional (glacio-lacustrine to marine) terrace orders and raised marine shorelines found between 0 and + 20 m. These features are mainly linked to glacio-eustasy and secondarily to Holocene neo-tectonics. This research derives from the interpretation of aerial photographs and remote sensing imagery along with geomorphological-stratigraphic field surveys and geochemical data. The Main Map illustrates an area with dominant palaeo-glacial and glacio-lacustrine morphology with extensive lacustrine deposits and well-developed lake systems characterising the Porvenir region.

Role of the River So~a in transfering mercury compounds into the gulf of Trieste

In presented work different mercury forms in inflow of River So~a at mixing zone between fresh and sea water have been investigated. Regarding to River So~a water regime three sampling periods have been proposed at nine sampling locations. Total Hg concentrations were between 4.5 and 174 ng/l with average value of 25.9 ng/ l. Most Hg (72%) was bounded to suspended matter. The highest values in water column were measured in May when the average total Hg concentration was 33.6 ng/l. Methylmercury (MeHg) concentrations were in wide range between 12.0 and 1350 pg/l (average 175 pg/l). Most MeHg was in dissolved form (85%). Dissolved Hg (DGM) concentration in water was between 0.03 to 2.6 ng/l. More than ten years after closure of the mercury mine in Idrija concentrations of different Hg species in River So~a remains very high. GEOLOGIJA 49/1, 113–121, Ljubljana 2006