32 research outputs found

    Brittle basement deformation during the Caledonian Orogeny observed by K‐Ar geochronology of illite‐bearing fault gouge in west‐central Sweden

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    This study presents K-Ar ages of illite from fault gouges in crystalline basement in centralwestern Sweden. Samples were taken from two faults that localized brittle deformation marginal to and within mafic dikes that intruded Paleoproterozoic granitoids. K-Ar ages from ten separated grain fractions span from 823 to 392 Ma. Older ages obtained (823 to 477 Ma) were influenced by a mixture of illite and K-feldspar; the latter likely formed during a hydrothermal event prior to faulting. The remaining ages (442.1±9.7 to 391.7±6.1 Ma) were obtained from fractions from both faults hosting only authigenic illite, and show that illite crystallized during the Scandian Caledonian orogeny. These results indicate that previously presumed autochthonous Caledonian basement was involved in continental contraction and subsequent collapse of the Caledonian orogen, influencing both the mode and depth of penetration of deformation into Baltica

    KunskapslÀget pÄ kÀrnavfallsomrÄdet 2018

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    KĂ€rnavfallsrĂ„det (rĂ„det) ger Ă„rligen ut en kunskapslĂ€gesrapport. Åretsrapport Ă€r uppdelad i tvĂ„ delar: Del 1 handlar om beslut under osĂ€kerhet. Regeringen ska framöver fatta beslut om ett slutförvar för anvĂ€nt kĂ€rnbrĂ€nsle och det kommer att fattas under osĂ€kerhet. Det i sig Ă€r inget ovanligt för regeringen utan görs hela tiden pĂ„ olika omrĂ„den, men det Ă€r dĂ€remot ett ovanligt komplicerat projekt. (Se kort översikt nedan). RĂ„det ger utifrĂ„n sin tvĂ€rvetenskapliga sammansĂ€ttning nĂ„gra exempel pĂ„ olika omrĂ„den med osĂ€kerheter och resonerar kring hur det gĂ„r att hantera och förhĂ„lla sig till osĂ€kerheter i beslutsfattande, sĂ„vĂ€l i allmĂ€nhet som nĂ€r det gĂ€ller ett beslut om ett slutförvar för anvĂ€nt kĂ€rnbrĂ€nsle i synnerhet. Del 2 innehĂ„ller en rapportering om rĂ„dets arbete och en kort beskrivning om vad som hĂ€nt pĂ„ kĂ€rnavfallsomrĂ„det i Sverige under 2017. Mycket har hĂ€nt under Ă„ret, exempelvis nĂ€r det gĂ€ller tillstĂ„ndsprocessen för anvĂ€nt kĂ€rnbrĂ€nsle, tillstĂ„ndsprocessen om utbyggnad för Slutförvaret för kortlivat avfall (SFR) och nĂ€r det gĂ€ller finansieringsfrĂ„gor. HĂ€r finns Ă€ven en kort beskrivning av vad som hĂ€nder nu nĂ€r regeringen den 23 januari 2018 har fĂ„tt Ă€rendet om ett slutförvar för anvĂ€nt kĂ€rnbrĂ€nsle pĂ„ sitt bord. Bakgrund till slutförvar, ansökningar och KBS-3-metoden NĂ€r det gĂ€ller ett beslut om ett slutförvar för anvĂ€nt kĂ€rnbrĂ€nsle Ă€r det av flera anledningar ett komplext projekt. Det Ă€r tekniskt komplicerat eftersom förvaret ska vara sĂ€kert i minst 100 000 Ă„r, s.k. lĂ„ngsiktigt sĂ€kert. AnlĂ€ggningstiden för slutförvaret Ă€r ovanligt lĂ„ng, det planeras vara klart först om ca 70–80 Ă„r. Vi vet inte vad som hĂ€nder med tekniken, klimatet eller i samhĂ€llet under de lĂ„nga tidshorisonterna. Det finns inte heller nĂ„got fĂ€rdigbyggt förvar för anvĂ€nt kĂ€rnbrĂ€nsle som vi kan dra lĂ€rdom av. En kĂ€rnkraftsreaktor drivs av kĂ€rnbrĂ€nsle som efter ca 5 Ă„rs anvĂ€ndning blir s.k. anvĂ€nt kĂ€rnbrĂ€nsle. Det högaktiva anvĂ€nda kĂ€rnbrĂ€nslet betraktas inte som kĂ€rnavfall, enligt kĂ€rntekniklagen, innan det ligger placerat i ett slutförvar. Det Ă€r reaktorinnehavarnas ansvar att ta hand om sitt kĂ€rnavfall och anvĂ€nda kĂ€rnbrĂ€nsle. För att ta sitt ansvar har reaktorinnehavarna tillsammans bildat bolaget Svensk KĂ€rnbrĂ€nslehantering AB (SKB) som planerar, driver och uppför mellanlager och slutförvar. SKB ansöker nu om att fĂ„ uppföra och driva ett slutförvar för anvĂ€nt kĂ€rnbrĂ€nsle enligt KBS-3-metoden. Ansökningarna gĂ€ller ett system som bestĂ„r av tvĂ„ anlĂ€ggningar; en inkapslingsanlĂ€ggning i Oskarshamns kommun och en slutförvarsanlĂ€ggning i Forsmark, Östhammars kommun. KBS-3-metoden bygger pĂ„ tre sĂ€kerhetsbarriĂ€rer: kopparkapslarna, bentonitleran och berget. Det anvĂ€nda kĂ€rnbrĂ€nslet ska kapslas in i kopparkapslar som dĂ€refter placeras i ett tunnelsystem pĂ„ ca 500 meters djup nere i berget. Kapslarna omges dĂ€refter med bentonitlera som ska svĂ€lla och skydda kapslarna. Planen Ă€r att deponera ca 6 000 kapslar med vardera ca 2 ton anvĂ€nt kĂ€rnbrĂ€nsle, totalt ca 12 000 ton. I dag ligger det ca 7 000 ton under vatten i bassĂ€nger iOskarshamn (Clab). SKB lĂ€mnade in sina ansökningar om tillstĂ„nd att fĂ„ uppföra, inneha och driva ett slutförvar för anvĂ€nt kĂ€rnbrĂ€nsle i mars 2011. Det krĂ€vs tillstĂ„nd, och tillstĂ„ndsprövningen sker i tvĂ„ separata processer. Mark- och miljödomstolen vid Nacka tingsrĂ€tt har berett ansökan enligt Miljöbalken (1998:808) och StrĂ„lsĂ€kerhetsmyndigheten (SSM) har berett ansökningarna enligt Lagen (1984:3) om kĂ€rnteknisk verksamhet (kĂ€rntekniklagen). Den 23 januari 2018 lĂ€mnade mark- och miljödomstolen och SSM sina yttranden tillsammans med ansökningarna till regeringen. Det Ă€r regeringen som prövar ansökningarna och dĂ€refter fattar beslut om huruvida verksamheten kan tillĂ„tas enligt miljöbalken (s.k. tillĂ„tlighet) och om tillstĂ„nd enligt kĂ€rntekniklagen. En utmaning med att bedöma ansökningarna Ă€r att de bygger pĂ„ referensutformningar som ska bli alltmer detaljerade, eftersom det tar lĂ„ng tid att bygga och driva förvaret. Under driftstiden ska tunnlar grĂ€vas och byggas samtidigt som kapslarna med anvĂ€nt kĂ€rnbrĂ€nsle ska placeras med bentonitlera runtom (deponeras). Yttrandena frĂ„n mark- och miljödomstolen och SSM överlĂ€mnades till regeringen under absoluta slutskedet av arbetet med denna kunskapslĂ€gesrapport. RĂ„det har alltsĂ„ inte haft dessa som bakgrund under skrivprocessen utan reflekterar endast kort kring dem

    Att ge grönt ljus till tjejer : En metoddiskussion utifrÄn projektet Equalizer - för jÀmstÀllda och inkluderande aktivitetsplatser.

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    Artikeln diskuterar den metod med "normstörningar" i fokus som utarbetats i forskningsprojektet Equalizer. Artikeln problematiser ocksÄ pÄ vilket sÀtt vi skapar normer för platstagande pÄ offentliga platser, men ocksÄ nÀr det handlar om vem som fÄr ta plats och vem som ska flytta pÄ sig

    Equalizer: Breaking down the barriers at informal outdoor sport and recreational spaces

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    A popular strategy for activating the urban population physically is to provide informal outdoor sport and recreational spaces. However, building an infrastructure does not assure physical activity among the wider population. For instance, girls tend to be underrepresented at public sport places. To create more equal physical activity opportunities in public space, we need to uncover and interpret the barriers. Therefore, outdoor sport and recreational spaces are interesting to examine, as they provide a possibility to understand gender in relation to norms, activity, and public space. The project Equalizer – a tool for equal and inclusive activity places deals with the perspectives of gender, place, and physical activity to create changes in the use of public informal outdoor sport and recreational spaces. This paper aims to discuss the experience-based, participatory method of disturbances used in the Equalizer project and some of the central findings and solutions. The findings indicate that the barriers for engaging in physical activity at informal outdoor sport and recreational spaces are multi-faceted, as are the possible solutions to overcome the barriers and open up the places to more people. We identified four types of solutions based on the identified barriers: spatial/physical, organisational/support-related, activity-related, and norm/representation-related

    On the occurrence of gallium and germanium in the Bergslagen ore province, Sweden

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    The presence of the critical and sought-after (semi-)metals gallium (Ga) and germanium (Ge) has previously been reported from mineralisations in the Bergslagen ore province, south central Sweden. Some of these reports were however recently shown to be questionable or erroneous. Here we summarise early analytical work on these metals in mineral deposits of the Bergslagen province, as well as briefly report new analytical data for Ga and Ge from recent, in part on-going work on different mineralisation types. The new data show that the sampled sulphide and iron oxide mineralisations in the Bergslagen province are overall not particularly enriched in Ga, and even less so with regards to Ge. One major exception is the significant Ga enrichment observed in skarn-hosted Fe-REE(-polymetallic) deposits of Bastnas type. Notably, these mineralisations also host increased contents of Ge. Based on this broader suite of sampled deposits, the suggested correlation between Ga and Al contents in previously studied material with relatively increased Ga grades, is in part contradicted, indicating that Ga is only in part sequestered through straightforward Al-substitution into aluminium silicate and oxide minerals. The mineralisations that do exhibit significantly increased Ge contents, in addition to the Bastnas-type deposits, are represented by both sulphide-dominated ones and Fe (-Mn) oxide-rich systems

    Ductile shear zones related to crustal shortening and domain boundary evolution in the central Fennoscandian Shield

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    The Paleoproterozoic part of the Fennoscandian Shield is composed of crustal components formed in different tectonic settings and generally separated by well-defined shear zone systems. An anomalous transitional boundary has been investigated by integrating structural analysis and geochronology with published geophysical data. The nature of this boundary is interpreted to be a consequence of an apparent stacking in the lower and middle crust initiating 1.87-1.86 Ga dextral shear along the Gavle-Rattvik Zone (GRZ) and adjacent shear zones, resulting in an arcuate northern boundary of the Bergslagen province. This boundary coincides with geophysical anomalies and temporal and metamorphic breaks. Owing to continuous convergence the pure-shear overprint component increased on the GRZ and caused a shift of dextral shear to the Hagsta Gneiss Zone with recorded shear at 1809 +/- 2 Ma. Most likely, both these structures are related to coeval shear zones farther to the east as a part of an similar to 1500 km long crustal, or possibly terrane, boundary. Citation: Hogdahl, K., H. Sjostrom, and S. Bergman (2009), Ductile shear zones related to crustal shortening and domain boundary evolution in the central Fennoscandian Shield, Tectonics, 28, TC1003, doi:10.1029/2008TC002277

    Geological relations and U-Pb geochronology of Hyttsjo granites in the Langban-Nordmark area, western Bergslagen, Sweden

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    The Hyttsjo granites occur in the extensively mineralised Langban-Nordmark area in the westernmost part of the Bergslagen ore province. They have been classified as late Svecokarelian granites due to their homogeneous and generally isotropic appearance in addition to a WR Rb/Sr age. Moreover, they have been considered as possible candidates for supplying essential metals to epigenetic mineralisation in this classic ore district. Two Hyttsjo granites yield U-Pb zircon data ages of 1791 2 and 1793 3 Ma, respectively, which overlap with emplacement ages of the adjacent 1.80-1.78 Ga Filipstad suite belonging to the Transscandinavian Igneous Belt (TIB). Mafic rocks occur quite abundantly associated with the Filipstad-type granite (sensu lato) and various types of mafic enclaves as well as hybrid rocks are present, suggesting a co-magmatic origin. Such mafic intrusives are also exposed in the vicinity of most known Hyttsjo-type plutons. Not least our observations that the former exhibit back-veining by granitic melts suggest intimate causal and temporal relationships between granite formation and mafic TIB rocks. The Hyttsjo granites were probably produced through partial melting related to the intrusion of hot, mafic magmas in and along the border between the TIB and the Svecofennian supracrustal and subvolcanic rocks. Thus, all available observations and data suggest that the Hyttsjo granites are intimately related to and most probable a product of TIB magmatism. Also, they do not lend any support for the hypothesis that the formation of the Hyttsjo granites represent a temporally separate intrusive episode. The Hyttsjo granites are therefore unlikely to be discernibly responsible for specific mineralisation in this area

    Invigning av tvÄ ombyggda skolgÄrdar

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    Forskningsprojektet Equalizer 2.0 syftade till att förĂ€ndra skolgĂ„rdar utifrĂ„n ett inkluderande och normkritiskt perspektiv, detta för att skapa större möjlighet till fysisk aktivitet och rörlighet hos unga mĂ€nniskor. Dessa invigdes det angivna datumet pĂ„ FĂ€ladsgĂ„rdens skola och Östratornskolan i Lund
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