Geological Survey of Sweden

About: Geological Survey of Sweden is a government organization based out in Uppsala, Sweden. It is known for research contribution in the topics: Metamorphism & Zircon. The organization has 316 authors who have published 671 publications receiving 18333 citations. The organization is also known as: Sveriges Geologiska Undersökning.

Marine conditions in central Sweden during the early Preboreal as inferred from a stable oxygen isotope gradient

Abstract: The marine benthic fauna and the δ 18 Oc of foraminifers and ostracods from six sites situated on a west-east transect through central Sweden have been analysed in order to estimate the palaeosalinity and palaeocirculation in this shallow-marine environment. The measurements have been undertaken on material from the early Preboreal, when the Baltic Basin was in contact with the North Sea through straits in central Sweden. The δ 18 Oc values have a more negative value towards the east, indicating decreasing salinity. This was the result of limited possibilities for marine water to penetrate into the Baltic Basin and the mixing with freshwater from the melting Fennoscandian ice-sheet. Four water masses existed in the area: a surface layer of freshwater, marine water from the North Sea, brackish-marine intermediate water on the Swedish west coast and brackish Yoldia Sea water in the Baltic Basin. The chronology is based on radiocarbon dates of marine fossils and, at one site, on the occurrence of the Vedde Ash (10 400-10 300 14 C yr BP). This is the first record from marine settings in Sweden. Copyright  2001 John Wiley & Sons, Ltd. Journal of Quaternary Science

Heavy metals in stockholm groundwater - concentrations and fluxes

Abstract: Sampling of groundwater in theQuaternary deposits was carried out at 70 sitesin Stockholm for, among other things, metalanalyses. The objectives were to get a notion of the metal content and to get a basis for anestimation of the order of magnitude of thegroundwater transported metal contribution to themain surface water bodies in comparison to otherroutes. Thus, in three watershed areaswithin the Stockholm Town, groundwater flow andmetal concentration propagation were simulatedand metal fluxes were calculated. Theconcentrations of heavy metals were in generalfound to be very high in comparison withgroundwater in forested areas. This was mostpronounced for mercury (Hg) and copper (Cu). Themost remarkable result was a Hg concentration of4.57 μg L-1 in the vicinity of a closed downhospital. The annual contribution of heavy metals(kg) by groundwater to the main surface waterbodies was estimated to: As (2.2), Cd (0.20), Co(4.9), Cr (3.1), Cu (34), Hg (0.06), Ni (28), Pb(2.2) Zn (118). These fluxes are much smallerthan those in forest ecosystems, due to lowergroundwater recharge in urban areas, where agreat part of the runoff is diverted bylandsealing, drainage, tunnels etc. The modelingresults emphasize the importance of the sorptionprocesses indicating that the modeled areas arein a non-steady state condition. It also showsthat the sources generating elevatedconcentrations of the high adsorptive metals Pband Hg are likely to be nearby.

Systematics of Hydrothermal Alteration at the Falun Base Metal Sulfide Deposit and Implications for Ore Genesis and Exploration, Bergslagen ore district, Fennoscandian Shield, Sweden

Abstract: The Paleoproterozoic Falun Zn-Pb-Cu-(Au-Ag) pyritic sulfide deposit in the Bergslagen ore district, Sweden, is enveloped by hydrothermally altered rocks metamorphosed to the lower amphibolite facie

Radon gas—A radiation hazard from radioactive bedrock and building materials

Abstract: Exposure to radioactive materials is not a problem solely connected with nuclear energy or nuclear weapons. The past year has witnessed real concern in Sweden regarding natural radiation hazards in the everyday environment, in particular exposure to high levels of radon gas and radon daughter products in dwellings. The source for the radon can be either building materials containing higher than normal amounts of radioactive elements, or bedrock and/or drift cover with relatively high concentraions of uranium.

Sparse 3D reflection seismic survey for deep-targeting iron oxide deposits and their host rocks, Ludvika Mines, Sweden

Abstract: . Many metallic mineral deposits have sufficient physical property contrasts, particularly density, to be detectable using seismic methods. These deposits are sometimes significant for our society and economic growth and can help to accelerate the energy transition towards decarbonization. However, their exploration at depth requires high-resolution and sensitive methods. Following a series of 2D seismic trials, a sparse, narrow source–receiver azimuth, 3D seismic survey was conducted in the Blotberget mine, in central Sweden, covering an area of approximately 6 km2 for deep-targeting iron oxide deposits and their host rock structures. The survey benefited from a collaborative work by putting together 1266 seismic recorders and a 32 t vibrator, generating 1056 shot points in a fixed geometry setup. Shots were fired at every 10 m where possible, and receivers were placed at every 10–20 m . Notable quality data were acquired despite the area being dominated by swampy places as well as by built-up roads and historical tailings. The data processing had to overcome these challenges for the static corrections and strong surface waves in particular. A tailored for hardrock setting and processing workflow was developed for handling such a dataset, where the use of mixed 2D and 3D refraction static corrections was relevant. The resulting seismic volume is rich in terms of reflectivity, with clear southeast-dipping reflections originating from the iron oxide deposits extending vertically and laterally at least 300 m beyond what was known from available boreholes. As a result, we estimate potential additional resources from the 3D reflection seismic experiment on the order of 10 Mt to be worth drilling for detailed assessments. The mineralization is crosscut by at least two major sets of northwest-dipping reflections interpreted to dominantly be normal faults and to be responsible for much of the lowland in the Blotberget area. Moreover, these post-mineralization faults likely control the current 3D geometry of the deposits. Curved and submerged reflections interpreted from folds or later intrusions are also observed, showing the geological complexity of the study area. The seismic survey also delineates the near-surface expression of a historical tailing as a by-product of refraction static corrections, demonstrating why 3D seismic data are so valuable for both mineral exploration and mine planning applications.