Petrography and geochemistry of the topaz-bearing granite stocks in Artjärvi and Sääskjärvi, western margin of the Wiborg rapakivi granite batholith

The Artjärvi and Sääskjärvi granite stocks at the western margin of the Wiborg rapakivi batholith are multiphase rapakivi granite intrusions in which the most evolved phase is topaz-bearing granite. The Artjärvi stock is composed of porphyritic and even-grained biotite granite and even-grained topaz granite, and the Sääskjärvi stock comprises even-grained biotite granite and porphyritic topazgranite. The granites are metaluminous to peraluminous A-type granites, showing within-plate (WPG) geochemical characteristics. The topaz granites from the Artjärvi and Sääskjärvi stocks are petrographically and geochemically similar to other topaz-bearing rapakivi granites in Finland. The anomalous geochemistry of the topaz granite is essentially magmatic; postmagmatic reactions have only slightly modified its composition. Greisen veins, some of which are mineralized, are widely found associated with the Artjärvi and Sääskjärvi stocks.The most characteristic feature of the Artjärvi granite stock is a stockscheider at the roof contact of the topaz granite. The stockscheider is composed of schlieren layering and pegmatite layers parallel to the contact. The most probable mechanism for the formation of the schlieren layering is velocity-gradient sorting parallel to the flow, which led to accumulation of mafic minerals along the upper contact of the topaz granite. Cooling and contraction of the topaz granite formed fractures parallel to the roof contact and the residual pegmatite magmas were injected along the fractures forming pegmatite layers. Textures like graphic intergrowths, aplitic groundmass and fan-shaped alkali feldspar crystals associated with the Artjärvi porphyritic biotite granite and pegmatite indicatecrystallization from undercooled magma. Miarolitic cavities found in the porphyritic biotite granite and topaz granite indicate at least local volatile saturation

Magmatic evolution of topaz-bearing granite stocks within the Wiborg rapakivi granite batholith

This study brings new insights into the magmatic evolution of natural F-enriched peraluminous granitic systems. The Artjärvi, Sääskjärvi and Kymi granite stocks within the 1.64 Ga Wiborg rapakivi granite batholith have been investigated by petrographic, geochemical, experimental and melt inclusion methods. These stocks represent late-stage leucocratic and weakly peraluminous intrusive phases typical of rapakivi granites worldwide. The Artjärvi and Sääskjärvi stocks are multiphase intrusions in which the most evolved phase is topaz granite. The Kymi stock contains topaz throughout and has a well-developed zoned structure, from the rim to the center: stockscheider pegmatite equigranular topaz granite porphyritic topaz granite. Geochemically the topaz granites are enriched in F, Li, Be, Ga, Rb, Sn and Nb and depleted in Mg, Fe, Ti, Ba, Sr, Zr and Eu. The anomalous geochemistry and mineralogy of the topaz granites are essentially magmatic in origin; postmagmatic reactions have only slightly modified the compositions. The Kymi equigranular topaz granite shows the most evolved character, and the topaz granites at Artjärvi and Sääskjärvi resemble the less evolved porphyritic topaz granite of the Kymi stock. Stockscheiders are found at the roof contacts of the Artjärvi and Kymi stocks. The stockscheider at Artjärvi is composed of biotite-rich schlieren and pegmatite layers parallel to the contact. The schlieren layering is considered to have formed by velocity-gradient sorting mechanism parallel to the flow, which led to the accumulation of mafic minerals along the upper contact of the topaz granite. Cooling and contraction of the topaz granite formed fractures parallel to the roof contact and residual pegmatite magmas were injected along the fractures and formed the pegmatite layers. The zoned structure of the Kymi stock is the result of intrusion of highly evolved residual melt from deeper parts of the magma chamber along the fractured contact between the porphyritic granite crystal mush and country rock. The equigranular topaz granite and marginal pegmatite (stockscheider) crystallized from this evolved melt. Phase relations of the Kymi equigranular topaz granite have been investigated utilizing crystallization experiments at 100 to 500 MPa as a function of water activity and F content. Fluorite and topaz can crystallize as liquidus phases in F-rich peraluminous systems, but the F content of the melt should exceed 2.5 - 3.0 wt % to facilitate crystallization of topaz. In peraluminous F-bearing melts containing more than 1 wt % F, topaz and muscovite are expected to be the first F-bearing phases to crystallize at high pressure, whereas fluorite and topaz should crystallize first at low pressure. Overall, the saturation of fluorite and topaz follows the reaction: CaAl2Si2O8 (plagioclase) + 2[AlF3]melt = CaF2 (fluorite) + 2Al2SiO4F2 (topaz). The obtained partition coefficient for F between biotite and glass D(F)Bt/glass is 1.89 to 0.80 (average 1.29) and can be used as an empirical fluormeter to determine the F content of coexisting melts. In order to study the magmatic evolution of the Kymi stock, crystallized melt inclusions in quartz and topaz grains in the porphyritic and the equigranular topaz granites and the marginal pegmatite were rehomogenized and analyzed. The homogenization conditions for the melt inclusions from the granites were 700 °C, 300 MPa, and 24 h, and for melt inclusions from the pegmatite, 700 °C, 100 MPa, and 24/96 h. The majority of the melt inclusions is chemically similar to the bulk rocks (excluding H2O content), but a few melt inclusions in the equigranular granite show clearly higher F and low K2O contents (on average 11.6 wt % F, 0.65 wt % K2O). The melt inclusion compositions indicate coexistence of two melt fractions, a prevailing peraluminous and a very volatile-rich, possibly peralkaline. Combined petrological, experimental and melt inclusion studies of the Kymi equigranular topaz granite indicate that plagioclase was the liquidus phase at nearly water-saturated (fluid-saturated) conditions and that the F content of the melt was at least 2 wt %. The early crystallization of biotite and the presence of muscovite in crystallization experiments at 200 MPa contrasts with the late-stage crystallization of biotite and the absence of muscovite in the equigranular granite, indicating that crystallization pressure may have been lower than 200 MPa for the granite.Tutkimuksessa selvitettiin fluoririkkaiden topaasipitoisten graniittien magmaattista evoluutiota petrografian, geokemian, sulasulkeuma ja kokeellisen petrologian tutkimuksien avulla. Tutkimuksen kohteena olivat Kaakkois-Suomen Viipurin rapakivikompleksissa esiintyvät Artjärven, Sääskjärven ja Kymin topaasipitoiset graniittistokit, jotka edustavat rapakivimagman viimeisimpiä ja kehittyneimpiä intruusiofaaseja. Tutkimukset osoittivat, että Artjärven ja Sääskjärven stokit ovat monifaasisia intruusioita, joissa kehittynein faasi on topaasigraniitti. Kymin stokin kaikki faasit ovat topaasipitoisia ja siinä on hyvin kehittynyt vyöhykerakenne: keskiosa on porfyyristä graniittia, sen ympärillä tasarakeista graniittia ja koko stokkia ympäröi reunapegmatiitti (stockscheider). Geokemiallisesti topaasigraniitit ovat rikastuneet F, Li, Be, Ga, Rb, Sn ja Nb alkuaineista sekä köyhtyneet Mg, Fe, Ti, Ba, Sr, Zr ja Eu alkuaineista. Topaasigraniittien geokemialliset ja mineralogiset erikoispiirteet (anomaalisuudet) ovat alkuperältään ensisijaisesti magmaattisia; myöhäismagmaattiset reaktiot ovat vain hieman muuttaneet topaasigraniittien koostumusta. Artjärven ja Kymin stokkien ulkoreunalla esiintyvät reunapegmatiittivyöhykkeet (stockscheider) kuvastavat mm. fluidifaasin erottumista graniittisulasta ja konsentroitumista magmasäiliön yläreunoille. Artjärven stocheider koostuu stokin yläkontaktin kanssa samansuuntaisista biotiitti-rikkaista kerroksista (schlieren) ja pegmatiittikerroksista. Kenttähavainnot, petrografiset ja geokemialliset tutkimukset viittaavat schlieren-kerrosten syntyneen magman virtausnopeuden muutoksen seurauksena ja pegmatiittikerrosten syntyneen jäännösmagmasta, joka tunkeutui topaasigraniitin jäähtyessä ja kutistuessa muodostuneisiin kontaktin suuntaisiin rakoihin. Kymin stokin vyöhykerakenne on syntynyt magmasäiliön syvemmistä osista nousseen jäännösmagman tunkeutuessa osittain sulan porfyyrisen topaasigraniitin ja stokkia ympäröivän rapakivigraniitin rakoilleeseen kontaktiin. Tasarakeinen topaasigraniitti ja reunapegmatiitti kiteytyivät tästä geokemiallisesti kehittyneemmästä magmasta. Kokeellisen petrologian laboratoriotutkimuksiin valittiin lähtömateriaaliksi Kymin tasarakeinen topaasigraniitti, joka on sulatettu ja jähmetetty lasiksi. Homogeeniselle lasille tehtiin kiteyttämiskokeita eri paine ja lämpötila olosuhteissa, sekä erilaisilla H2O-aktiivisuus arvoilla ja fluoripitoisuuksilla, jolloin saatiin selville graniitissa esiintyvien mineraalien (topaasi, fluoriitti, kvartsi, plagioklaasi, kalimaasälpä, kiille) stabiilisuuskentät. Kiteyttämiskokeet osoittivat, että topaasi ja fluoriitti kiteytyvät suoraan magmasta, mutta sulan fluoripitoisuuden on oltava yli 2.5 - 3.0 wt % ennen kuin topaasi kiteytyy. Kokeiden tuloksena määritettiin fluorin keskimääräiseksi jakautumiskertoimeksi biotiitin ja lasin välillä 1.29. Jakautumiskertoimen avulla voidaan laskea biotiitin fluoripitoisuuden perusteella biotiitin kanssa tasapainossa olleen alkuperäisen sulan fluoripitoisuus. Kiteytyneet sulasulkeumat Kymin topaasigraniittien topaasissa ja kvartsissa homogenisoitiin 3 kbar paineessa ja 700 °C lämpötilassa ja pegmatiitin sulasulkeumat 1 kbar paineessa ja 900 °C lämpötilassa. Lasiksi jähmettyneet sulasulkeumat analysoitiin elektronimikroanalysaattorilla. Kemiallisten analyysien perusteella saatiin selville alkuperäisen 1600 miljoonaa vuotta sitten sulana olleiden graniittisten ja pegmatiittisen magmojen koostumukset. Sulasulkeumien koostumukset osoittavat Kymin topaasigraniittien ja pegmatiitin kiteytyneen hyvin vesirikkaista magmoista. Sulasulkeumatutkimukset antoivat viitteitä myös erittäin fluoririkkaasta magmasta ja mahdollisesti kahden sulan olemassaolosta Kymin stokin kiteytyessä. Yhdistetyt petrologiset, kokeelliset ja sulasulkeumatutkimukset Kymin tasarakeisesta topaasigraniitista viittaavat siihen, että graniitin kiteytyminen alkoi plagioklaasin kiteytymisellä lähes vesikylläisissä olosuhteissa magman fluoripitoisuuden ollessa vähintään 2 wt % ja paineen ollessa alle 2 kbar

Volcanic ash as a resource for future research on Earth and the Moon

When a volcano erupts, it is often associated with destruction, particularly damage to infrastructure and loss of life. But these natural events also offer unexpected research opportunities, leading to serendipitous discoveries. This was the case for the volcanic events that made the headlines during 19 September to 25 December 2021, on the Canarian Island of La Palma. Rather than viewing the voluminous ash that erupted as a waste material needing to be removed as soon as possible, we saw the many possibilities that this remarkable material could offer science and engineering. Sustainability is a word that is commonly used in connection with geology these days. Here we present some possibilities of how the La Palma ash can be re‐purposed for use on this planet but also help us to develop new ideas for the future living on the Moon

Association between perinatal and childhood risk factors with mental disorders in adolescence

Abstract Many adult diseases have their origins in early life events. Much remains unrevealed in this field, especially concerning associations between perinatal complications and early manifestation of psychiatric disorders. The aim of this work is to assess the association of early adverse life events and later psychiatric disorders in adolescence. This study sample consists of 508 adolescent inpatients aged 13–17 years in need of acute psychiatric hospitalization in an adolescent psychiatric ward of Unit 70 in Oulu University Hospital between years 2001–2006. A diagnostic semi-structured interview, the Schedule for Affective Disorder and Schizophrenia for School-Age Children Present and Lifetime (K-SADS-PL), was carried out to assess psychiatric disorders according to DSM-IV criteria. The information on obstetric complications was obtained simultaneously. Birth measures data were derived from the Medical Birth Register. Diagnoses of epilepsy and other convulsions and child psychiatric diagnoses based on hospital treatment on the child psychiatric ward were obtained from the Finnish Care Register of Health Care. Delivery complications, especially section, increased the likelihood for conduct disorders among adolescent boys. The adolescent boys were shorter and had higher ponderal index at birth compared to healthy controls. In boys high ponderal index was associated with internalizing disorders in adolescence. Febrile and other convulsions and epilepsy in childhood associated with suicide attempts among adolescent boys. The likelihood for personality disorder was 14-fold among adolescents with febrile or other convulsions in childhood and three-fold among those with childhood epilepsy. Previous child psychiatric care associated with self-mutilative behaviour and child welfare placement in adolescence. Among boys, a history of child psychiatric care was related to anxiety and conduct disorders in adolescence, and among girls, mother’s unemployment, psychiatric problems and family malfunction quantified as a low GARF. These findings imply that especially boys with adverse biological perinatal and early childhood adversities are at risk for mental disorders in adolescence. Girls, on the other hand, in the light of this study, seem to be vulnerable especially to adverse environmental circumstances like family malfunction and maternal problems.Tiivistelmä Varhaiset terveydelle epäsuotuisat tekijät altistavat sairauksille aikuisena. Etenkin perinataalivaiheen ongelmien ja alaikäisenä puhjenneiden psykiatristen häiriöiden välisestä yhteydestä tiedetään kuitenkin vähän. Tämän työn tarkoitus on tutkia varhaisten epäsuotuisien tapahtumien yhteyttä nuoruusiässä puhjenneisiin psykiatrisiin häiriöihin. Tutkimusaineisto koostuu 508:sta, iältään 13–17-vuotiasta nuoresta, jotka on otettu Oulun yliopistollisen sairaalan nuorisopsykiatrian akuuttiosastolle (osasto 70) hoitoon vuosina 2001–2006. Osastojakson aikana nuoret tutkittiin käyttäen puolistrukturoitua K-SADS-PL-haastattelua, jolla arvioitiin psykiatrisia häiriöitä DSM-IV-tautiluokituksen mukaisesti. Samalla saatiin tieto nuoren syntymään liittyneistä obstetrisista komplikaatioista. Syntymämitat selvitettiin syntyneiden lasten rekisteristä ja tiedot lapsuusiän kuume- ja muista kouristuksista, lapsuusiän epilepsioista ja lastenpsykiatrisista hoitojaksoista poimittiin sairaaloiden hoitoilmoitusrekisteristä. Synnytyskomplikaatiot, etenkin sektio, lisäsivät poikien käytöshäiriöiden riskiä nuoruudessa. Tutkimusaineiston pojille oli tyypillisempää lyhyt syntymäpituus ja iso ponderaalimitta verrattuna samanikäisiin terveisiin kontrolleihin. Pojilla suuri ponderaalimitta lisäsi erityisesti internalisoivien häiriöiden riskiä nuoruudessa. Lapsuusiän kuume- ja muut kouristukset sekä epilepsia assosioituivat poikien itsemurhayrityksiin nuoruudessa. Kuume- ja muut kouristukset suurensivat persoonallisuushäiriön riskiä nuoruudessa 14-kertaisesti, epilepsia kolminkertaisesti. Aiempi lastenpsykiatrinen osastohoito oli yhteydessä nuorten itsensä vahingoittamiseen esimerkiksi viiltelemällä sekä sijoitukseen kodin ulkopuolelle. Lisäksi aiempi lastenpsykiatrinen hoito liittyi pojilla ahdistus- ja käytöshäiriöihin nuoruudessa ja tytöillä äidin työttömyyteen, äidin psykiatrisiin ongelmiin ja perheen huonoon toimintakykyyn GARF- mittarin perusteella arvioituna. Nämä tulokset viittaavat siihen, että etenkin pojat sairastuvat herkemmin psykiatriseen häiriöön nuoruudessa varhaisvaiheiden epäsuotuisien tekijöiden seurauksena. Toisaalta tämän tutkimuksen valossa tyttöjen psykiatriseen sairastumiseen jo lapsuudessa vaikuttivat erityisesti epäsuotuisat ympäristötekijät, jotka liittyvät etenkin perheeseen ja äitiin

Snow in mineral exploration:examples and practices in glaciated terrain

Abstract Although the origin of the snow is atmospheric, heat and gasses coming from underlying soil affect the concentration of hydrocarbons and elements in snow. For testing the use of snow in geochemical exploration, a test campaign was carried out in three different mineralization types in northern Finland: Au-Co, P-REE and Cu mineralizations. The snow samples were collected from the bottom of snow cover in two consecutive years. Two methods for analysing geochemical signatures of mineralized bedrock were applied to these snow samples: Spatiotemporal Geochemical Hydrocarbons (SGH) and ultra-trace elements determination by single collector high resolution inductively coupled plasma mass spectrometry (SC-HR-ICP-MS). The SGH method is based on detection of the hydrocarbons that are decomposition products of bacteria that use specific mineralization in their growth phase. In the case of the inductively coupled mass spectrometry, the content of a wide range of elements was determined. The results of both methods showed that the traces inherited from the tested mineralization can be observed in snow. The SGH signature located the Au-Co mineralization using an Au template and the Cu mineralization using a Cu template, although low signal repeatability may be the weakness. The response to the P-REE mineralization with a Polymetallic template was unclear. An improvement was achieved by reinterpreting the result with a customized template for REE. In addition, the repeatability with reinterpreted results showed similarities in the results between the sampling rounds. In the case of the SC-HR-ICP-MS method, results for several elements (e.g. As, Cu, Fe) showed a clear response over the mineralized zones for all three mineralization types. Mineral exploration would benefit using of snow as sampling material: this activity leaves virtually no footprint. Further studies are needed to improve the confidence and reliability in the use of snow as a sampling medium in mineral exploration

The Recycling of End-of-Life Lithium-Ion Batteries and the Phase Characterisation of Black Mass

Black mass is the industry term applied to end-of-life (EoL) lithium-ion batteries that have been mechanically processed for potential use as a recycled material to recover the valuable metals present, including cobalt, lithium, manganese, nickel and copper. A significant challenge to the effective processing of black mass is the complexity of the feed material. Two samples of black mass from a European source were analysed using a combination of methods including automated SEM-EDS (AMICS) to characterise and quantify the phases present and particle chemistry. Micro X-CT imaging, overlain onto automated mineralogy images, enabled the 3D morphology of the particles to be determined. Micro-XRF was used to map the copper, nickel, manganese and cobalt-bearing phases. Since Li cannot be detected using SEM-EDS, its abundance was semi-quantified using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The integration of these complimentary analytical methods allowed for detailed phase characterisation, which may guide the potential hydrometallurgical or pyrometallurgical recycling routes and chemical assaying

Morphology‐Dependent Magnetic Properties in Shallow‐Water Ferromanganese Concretions

Ferromanganese concretions commonly occur in shallow-water coastal regions worldwide. In the Baltic Sea, they can record information about past and present underwater environments and could be a potential source for critical raw materials. We report on their microstructural characteristics and magnetic properties and link them to their formation mechanisms and environmental significance. Microstructural investigations from nano- and micro-computed tomography, electron microscopy, and micro-X-ray fluorescence elemental mapping reveal diverse growth patterns within concretions of different morphologies. Alternating Fe- and Mn-rich growth bands indicate fluctuating redox conditions during formation. Bullet-shaped magnetofossils, produced by magnetotactic bacteria, are present, which suggests the influence of bacterial activity on concretion formation. Spheroidal concretions, which occur in deeper and more tranquil environments, have enhanced microbial biomineralization and magnetofossil preservation. Conversely, crusts and discoidal concretions from shallower and more energetic environments contain fewer magnetofossils and have a greater detrital content. Our results provide insights into concretion formation mechanisms and highlight the importance of diagenetic processes, oxygen availability, and bacterial activity in the Baltic Sea.peerReviewe