The Paleoproterozoic Kandalaksha-Kolvitsa gabbro-anorthosite complex (Fennoscandian Shield): new U-Pb, Sm-Nd and Nd-Sr (ID-TIMS) isotope data on the age of formation, metamorphism and geochemical features of zircon (LA-ICP-MS)

2020 ◽  
Author(s):  
Ekaterina Steshenko ◽  
Tamara Bayanova ◽  
Pavel Serov ◽  
Nadezhda Ekimova
Keyword(s):  
Early Stage ◽  
Crustal Contamination ◽  
Basic Research ◽  
Granulite Metamorphism ◽  
Icp Ms ◽  
Zircon Crystallization ◽  
Mantle Reservoir ◽  
Single Zircon ◽  
Research Contract ◽  
Anorthosite Complex

<p>The paper provides new U-Pb, Sm-Nd and Nd-Sr isotope-geochronological data on rocks of the Paleoproterozoic Kandalaksha-Kolvitsa gabbro-anorthosite complex. REE contents in zircons from basic rock varieties of the Kandalaksha-Kolvitsa area have been defined in situ using LA-ICP-MS. Plots of REE distribution have been constructed, confirming the magmatic origin of zircon. Temperatures of zircon crystallization have been estimated, using a Ti-in-zircon geochronometer. For the first time, the U-Pb method with <sup>205</sup>Pb artificial tracer has been applied to date single zircon grains (2448±5 Ma) from metagabbro of the Kolvitsa massif. The U-Pb analysis of zircon from anorthosites of the Kandalaksha massif has dated the early stage of the granulite metamorphism at 2230±10 Ma. The Sm-Nd isotope age has been estimated on metamorphic minerals (apatite, garnet, sulfides) and the rock at 1985±17 Ma (granulite metamorphism) for the Kolvitsa massif, 1887±37 Ma (high-temperature metasomatic transformations) and 1692±71 Ma (regional fluid reworking) for the Kandalaksha massif. The Sm-Nd model age of metagabbro is 3.3 Ga with negative value εNd=4.6, which corresponds either with processes of crustal contamination, or with primary enriched mantle reservoir of primary magmas.</p><p>This research was funded by the Scientific Research Contract of GI KSC RAS No. 0226-2019-0053, grants of the Russian Foundation for Basic Research NoNo. 18-05-70082 «Arctic Resources», 18-35-00246 mol_a, and the Presidium RAS Program No. 8.</p><p> </p>

scholarly journals The Paleoproterozoic Kandalaksha-Kolvitsa Gabbro-Anorthosite Complex (Fennoscandian Shield): New U–Pb, Sm–Nd, and Nd–Sr (ID-TIMS) Isotope Data on the Age of Formation, Metamorphism, and Geochemical Features of Zircon (LA-ICP-MS)

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 254 ◽  
Author(s):  
Ekaterina N. Steshenko ◽  
Tamara B. Bayanova ◽  
Pavel A. Serov
Keyword(s):  
Inductively Coupled Plasma ◽  
Early Stage ◽  
Crustal Contamination ◽  
Inductively Coupled ◽  
Granulite Metamorphism ◽  
Icp Ms ◽  
Zircon Crystallization ◽  
Mantle Reservoir ◽  
Single Zircon ◽  
Anorthosite Complex

The paper provides new U–Pb, Sm–Nd, and Nd–Sr isotope-geochronological data on rocks of the Paleoproterozoic Kandalaksha-Kolvitsa gabbro-anorthosite complex. Rare earth element (REE) contents in zircons from basic rock varieties of the Kandalaksha-Kolvitsa area were analyzed in situ using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Plots of REE distribution were constructed, confirming the magmatic origin of zircon. Temperatures of zircon crystallization were estimated using a Ti-in-zircon geochronometer. The U–Pb method with a 205Pb artificial tracer was first applied to date single zircon grains (2448 ± 5 Ma) from metagabbro of the Kolvitsa massif. The U–Pb analysis of zircon from anorthosites of the Kandalaksha massif dated the early stage of the granulite metamorphism at 2230 ± 10 Ma. The Sm–Nd isotope age was estimated on metamorphic minerals (apatite, garnet, sulfides) and whole rock at 1985 ± 17 Ma (granulite metamorphism) for the Kolvitsa massif and at 1887 ± 37 Ma (high-temperature metasomatic transformations) and 1692 ± 71 Ma (regional fluid reworking) for the Kandalaksha massif. The Sm–Nd model age of metagabbro was 3.3 Ga with a negative value of εNd = 4.6, which corresponds with either processes of crustal contamination or primary enriched mantle reservoir of primary magmas.

New Nd-Sr isotope-geochronological evidence of its affinity to the East-Scandinavian Large Igneous Province (The Kandalaksha-Kolvitsa gabbro-anorthosite complex, Russia)

2021 ◽  
Author(s):  
Ekaterina Steshenko ◽  
Pavel Serov ◽  
Evgeniy Kunakkuzin ◽  
Nadezhda Ekimova ◽  
Dmitriy Elizarov ◽  
...  
Keyword(s):  
Large Igneous Province ◽  
Layered Intrusions ◽  
Sr Isotope ◽  
Geochronological Data ◽  
Igneous Province ◽  
Rfbr Grant ◽  
Mantle Reservoir ◽  
The Baltic ◽  
Research Contract ◽  
Anorthosite Complex

<p>The article provides new Sm-Nd and Nd-Sr isotope-geochronological data on rocks of the Paleoproterozoic Kandalaksha-Kolvitsa gabbro-anorthosite complex.</p><p>The Sm-Nd and Rb-Sr studies have provided data on isotope compositions of neodymium and strontium in rocks of both massifs. The isotope compositions of neodymium (eNd) range from -0.02 in norites of the Kandalaksha massif to -5.53 in lens bodies of gneiss granites of the Kolvitsa massif</p><p>Weakly radiogenic values of eNd = -1.0 – -1.2 dominate, which complies with characteristic values of Paleoproterozoic layered intrusions in Fennoscandia. Isotope compositions of strontium ranging from 0.7013 to 0.7025 also reflect typical values of a Paleoproterozoic igneous province [.</p><p>New data suggest that the Kandalaksha-Kolvitsa gabbro-anorthosite complex is confined to the East-Scandinavian Large Igneous Province with a protracted evolution at the turn of 2.53-2.39 Ga. According to geochronological and isotope Nd-Sr data, rocks of the Kandalaksha-Kolvitsa complex seem to have the same anomalous mantle source with Paleoproterozoic layered intrusions in the Baltic Shield (Fig. 3). The latter include Cu-Ni-Co-Cr+PGE deposits in the Monchegorsk ore area and Pechenga, Cr ores in the Pados massif, Fe-Ti-V Kolvitsa deposit, PGE and Cu-Ni Fedorovo-Pana layered complex  and Burakovsky intrusion, Cu-Ni-Co+PGE deposits in Finland, i.e. Kemi, Penikat, Akanvaara, Kontelainen, Tornio and many other. These deposits formed at two episodes, 2.53-2.39 Ga and 2.0-1.8 Ga, that refer to the beginning of rifting and the late rifting stage of the Fennoscandian Shield evolution, respectively.</p><p>Rocks of these intrusions referred to the pyroxenite-gabbronorite-anorthosite formation have similar isotope-geochemical features:</p><p>1) according to U-Pb and Sm-Nd geochronological data, the formation time span is 2530 to 2380 Ma;</p><p>2) the mantle reservoir feeding magmas that formed the massifs is rich in lithophile elements;  I<sub>Sr</sub> values vary from 0.702 to 0.706, ε<sub>Nd</sub>(T) varies from +2 to -6;</p><p>3) the model Sm-Nd ages of T<sub>DM</sub> protoliths are 2.8-3.3 Ga.</p><p>The scientific research has been carried out in the framework of the State Research Contract of GI KSС RAS No. 0226-2019-0053, RFBR grant No. 18-05-70082 «Arctic’s Resources» and Presidium RAS Program No. 8.</p>

scholarly journals EU FP7 research funding for an orphan drug (Orfadin®) and vaccine (Hep C) development: a success and a failure?

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
L. Schmidt ◽  
O. Sehic ◽  
C. Wild
Keyword(s):  
Hepatitis C ◽  
Late Stage ◽  
Research Funding ◽  
Early Stage ◽  
Basic Research ◽  
Pharmaceutical Products ◽  
Clinical Development ◽  
Clinical Indication ◽  
Market Authorisation ◽  
Risk Capital

Abstract Background We considered the extent of the contribution of publicly funded research to the late-stage clinical development of pharmaceuticals and medicinal products, based on the European Commission (EC) FP7 research funding programme. Using two EC FP7-HEALTH case study examples—representing two types of outcomes—we then estimated wider public and charitable research funding contributions. Methods Using the publicly available database of FP7-HEALTH funded projects, we identified awards relating to late-stage clinical development according to the systematic application of inclusion and exclusion criteria, classified them according to product type and clinical indication, and calculated total EC funding amounts. We then identified two case studies representing extreme outcomes: failure to proceed with the product (hepatitis C vaccine) and successful market authorisation (Orfadin® for alkaptonuria). Total public and philanthropic research funding contributions to these products were then estimated using publicly available information on funding. Results 12.3% (120/977) of all EC FP7-HEALTH awards related to the funding of late-stage clinical research, totalling € 686,871,399. Pharmaceutical products and vaccines together accounted for 84% of these late-stage clinical development research awards and 70% of its funding. The hepatitis C vaccine received total European Community (FP7 and its predecessor, EC Framework VI) funding of €13,183,813; total public and charitable research funding for this product development was estimated at € 77,060,102. The industry sponsor does not consider further development of this product viable; this now represents public risk investment. FP7 funding for the late-stage development of Orfadin® for alkaptonuria was so important that the trials it funded formed the basis for market authorisation, but it is not clear whether the price of the treatment (over €20,000 per patient per year) adequately reflects the substantial public funding contribution. Conclusions Public and charitable research funding plays an essential role, not just in early stage basic research, but also in the late-stage clinical development of products prior to market authorisation. In addition, it provides risk capital for failed products. Within this context, we consider further discussions about a public return on investment and its reflection in pricing policies and decisions justified.

scholarly journals Toxicity Induced by Cytokines, Glucose, and Lipids Increase Apoptosis and Hamper Insulin Secretion in the 1.1E7 Beta Cell-Line

2021 ◽  
Vol 22 (5) ◽  
pp. 2559
Author(s):  
Antonia Diaz-Ganete ◽  
Aranzazu Quiroga-de-Castro ◽  
Rosa M. Mateos ◽  
Francisco Medina ◽  
Carmen Segundo ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Cell Line ◽  
High Glucose ◽  
Secretory Pathway ◽  
Early Stage ◽  
Hybrid Cell ◽  
Basic Research ◽  
Stress Markers ◽  
Beta Cell Line ◽  
Starting Point

Basic research on types 1 and 2 diabetes mellitus require early stage studies using beta cells or cell lines, ideally of human origin and with preserved insulin secretion in response to glucose. The 1.1E7 cells are a hybrid cell line resulting from the electrofusion of dispersed human islets and PANC-1 cells, capable of secreting insulin in response to glucose, but their survival and function under toxic conditions remains untested. This characterization is the purpose of the present study. We treated these cells with a cytokine mix, high glucose, palmitate, and the latter two combined. Under these conditions, we measured cell viability and apoptosis (MTT, Caspase Glo and TUNEL assays, as well as caspase-8 and -9 levels by Western blotting), endoplasmic reticulum stress markers (EIF2AK3, HSPA4, EIF2a, and HSPA5) by real-time PCR, and insulin secretion with a glucose challenge. All of these stimuli (i) induce apoptosis and ER stress markers expression, (ii) reduce mRNA amounts of 2–5 components of genes involved in the insulin secretory pathway, and (iii) abrogate the insulin release capability of 1.1E7 cells in response to glucose. The most pronounced effects were observed with cytokines and with palmitate and high glucose combined. This characterization may well serve as the starting point for those choosing this cell line for future basic research on certain aspects of diabetes.

scholarly journals Magmatic history of the Oldest Toba Tuff inferred from zircon U–Pb geochronology

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hisatoshi Ito
Keyword(s):  
Caldera Collapse ◽  
Zircon Dating ◽  
Icp Ms ◽  
Zircon Crystallization ◽  
History Of ◽  
Eruption Age ◽  
Magmatic History

Abstract The magmatic history of the Oldest Toba Tuff (OTT), the second largest in volume after the Youngest Toba Tuff (YTT), northern Sumatra, Indonesia, was investigated using U–Pb zircon dating by LA-ICP-MS. Zircon dates obtained from surface and interior sections yielded ages of 0.84 ± 0.03 Ma and 0.97 ± 0.03 Ma, respectively. The youngest OTT zircon ages were in accordance with the 40Ar/39Ar eruption age of ~ 0.8 Ma, whereas the oldest zircon dates were ~ 1.20 Ma. Therefore, the distribution of zircon U–Pb ages is interpreted to reflect protracted zircon crystallization, suggesting that the estimated 800–2,300 km3 of OTT magma accumulated and evolved for at least 400,000 years prior to eruption. This result is comparable to the volume and timescales of YTT magmatism. The similarities of both magmatic duration and geochemistry between OTT and YTT may indicate that they are similar in size and that the caldera collapse that generated OTT might be much larger previously interpreted.

How to disclose local equilibrium in subducted metapelites from the Cima Lunga Unit (Central Alps)

2020 ◽  
Author(s):  
Francesca Piccoli ◽  
Pierre Lanari ◽  
Jörg Hermann ◽  
Thomas Pettke
Keyword(s):  
High Pressure ◽  
Early Stage ◽  
Local Equilibrium ◽  
White Mica ◽  
Geochemical Data ◽  
Ultramafic Rocks ◽  
Central Alps ◽  
Large White ◽  
Icp Ms ◽  
Polyphase Inclusions

<p>Subducted metapelites are more prone to re-equilibrate during exhumation than mafic or ultramafic rocks to the point that recognizing high-pressure (HP) relicts is often very challenging. Geologic evidence from the Cima Lunga Unit (Central Alps) show this apparent discrepancy between high to ultra-high pressure metamorphism (28 kbar and 780 °C) recorded in mafic/ultramafic lenses, and Barrovian metamorphism (<10 kbar, 650°C) in the adjacent metapelitic rocks. We collected a white mica – garnet – biotite – plagioclase – kyanite (+ quartz, + zircon, + rutile) bearing metapelite adjacent to the garnet metaperidotite lens that displays an apparently well equilibrated Barrovian mineral assemblage (garnet + plagioclase + biotite), with no macroscopic or microtextural indication of a HP and/or HT metamorphic event (e.g. omphacite crystals; migmatitic texture; polyphase inclusions). Nevertheless, microstructures like atoll-like garnet or large white mica flakes surrounded by biotite and ilmenite replacing rutile suggest incomplete re-equilibration. We investigated garnet and phengite crystals by electron probe and laser ablation-ICP-MS mapping. Major and trace element mapping reveals very complex mineral zoning in both minerals. In particular, high Ti content in phengite and increasing P and Zr contents in pyrope-rich garnet indicate that the studied rock underwent a HP-HT event. This is also supported by Zr in rutile thermometry that indicates temperatures well above the Barrovian metamorphism (T > 700 °C). We combined detailed textural analysis with petrological-geochemical data and thermodynamic modelling to reconstruct the metamorphic evolution of the studied rock. We show that, thank to incomplete re-equilibration, the rock documents an evolution from prograde to UHP-HT peak (27 kbar and 800 °C) to retrograde (Barrovian) conditions (10 kbar and 620 °C). Noteworthy, peak metamorphic conditions of metapelite coincide with peak metamorphic conditions of the garnet metaperidotite. Lastly, geochemical evidence for minor wet melting of the studied metapelite at HP-HT conditions was recognized and is likely linked to the dehydration of chlorite to form garnet peridotite in the adjacent ultramafic body. We propose that metapelites and ultramafic rocks were coupled before subduction or at least in its early stage. This finding opens new scenarios for the geodynamic interpretation of the Cima Lunga unit. We propose that the ultramafic lenses at Cima di Gagnone were parts of the exhumed and serpentinised mantle emplaced at the hyper-extended European continental margin of the Piemont-Ligurian ocean. Slices of the margin were detached and tectonically mixed in the subduction channel. These new constraints call for re-evaluation of the paleogeographic position of the Adula-Cima Lunga nappe.</p>

scholarly journals Mineralogical and geochemical characterisation of the Kipawa syenite complex, Quebec: implications for rare-earth element deposits

2022 ◽  
Author(s):  
S Matte ◽  
M Constantin ◽  
R Stevenson
Keyword(s):  
Rare Earth ◽  
Rare Earth Element ◽  
Earth Element ◽  
Crustal Contamination ◽  
Hydrothermal Activity ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
Gneissic Granite ◽  
Icp Ms ◽  
Regional Tectonic

The Kipawa rare-earth element (REE) deposit is located in the Parautochton zone of the Grenville Province 55 km south of the boundary with the Superior Province. The deposit is part of the Kipawa syenite complex of peralkaline syenites, gneisses, and amphibolites that are intercalated with calc-silicate rocks and marbles overlain by a peralkaline gneissic granite. The REE deposit is principally composed of eudialyte, mosandrite and britholite, and less abundant minerals such as xenotime, monazite or euxenite. The Kipawa Complex outcrops as a series of thin, folded sheet imbricates located between regional metasediments, suggesting a regional tectonic control. Several hypotheses for the origin of the complex have been suggested: crustal contamination of mantle-derived magmas, crustal melting, fluid alteration, metamorphism, and hydrothermal activity. Our objective is to characterize the mineralogical, geochemical, and isotopic composition of the Kipawa complex in order to improve our understanding of the formation and the post-formation processes, and the age of the complex. The complex has been deformed and metamorphosed with evidence of melting-recrystallization textures among REE and Zr rich magmatic and post magmatic minerals. Major and trace element geochemistry obtained by ICP-MS suggest that syenites, granites and monzonite of the complex have within-plate A2 type anorogenic signatures, and our analyses indicate a strong crustal signature based on TIMS whole rock Nd isotopes. We have analyzed zircon grains by SEM, EPMA, ICP-MS and MC-ICP-MS coupled with laser ablation (Lu-Hf). Initial isotopic results also support a strong crustal signature. Taken together, these results suggest that alkaline magmas of the Kipawa complex/deposit could have formed by partial melting of the mantle followed by strong crustal contamination or by melting of metasomatized continental crust. These processes and origins strongly differ compare to most alkaline complexes in the world. Additional TIMS and LA-MC-ICP-MS analyses are planned to investigate whether all lithologies share the same strong crustal signature.

Isotope systematics (Pb-Nd-Sr) and LA-ICP-MS (REE, Os, PGE) data on time, duration and origin of Paleoproterozoic complex deposits in the N-E part of the Arctic region, Fennoscandian Shield

2021 ◽  
Author(s):  
Tamara Bayanova ◽  
Pavel Serov ◽  
Svetlana Drogobuzhskaya
Keyword(s):  
Arctic Region ◽  
Fennoscandian Shield ◽  
The Arctic ◽  
Layered Intrusions ◽  
Time Duration ◽  
Time Activity ◽  
Sulphide Minerals ◽  
Icp Ms ◽  
Mantle Reservoir ◽  
Isotope Systematics

<p>The isotope U-Pb system on zircon and baddeleyite reflects the precise age of the origin (2.5, 2.45 and 2.4 Ga) and duration (more than 100 Ma) for Cu-Ni and PGE complex deposits widespread in the N-E part of the Fennoscandian Shield. The Monchegorsk, Fedorovo-Pansky and Mt. Generalskaya layered intrusions and ore regions of the orthomagmatic Cu-Ni and PGE deposits with Pt-Pd reefs originated on the continental crust (3.7 Ga). Main phases of gabbronorites were formed mainly at 2.5 Ga and secondary anorthosites at 2.45 Ga, according to U-Pb data on zircon-baddeleyite geochronometries. The Imandra lopolith with Cr deposits was active from 2.45 Ga to 2.4 Ga due to dyke deformation complexes. Isotope Sm-Nd studies and investigations of rock-forming and sulphide minerals from the deposits indicated coeval ages and 3 magmatic time activity with positive epsilon Nd. Deformation or metamorphic events were dated using the Rb-Sr system on minerals and whole rocks from the deposits at 1.9-1.8 Ga.</p><p>The Pados Cr (2.08 Ga), Pechenga Cu-Ni (1.98 Ga) and Kolvitsa Ti-Mg (1.89 Ga) orthomagmatic deposits were dated, using the Pb-Nd-Sr isotope systematics. The mentioned deposits originated probably on the oceanic crust (2.7 Ga). According to new in situ LA-ICP-MS data on Os, PGE and REE concentration in zircon, baddeleyite and sulphide minerals from the complex deposits are characterized by subchondritic sources (Malitch et al., 2019). Paleoproterozoic layered intrusions (2.5-1.8 Ga) and deposits were formed from the plume enrichment mantle reservoir (EM-1), according to Nd-Sr data on whole rocks. Baddeleyite as a mantle mostly mineral (Zircon, 2003) reflects the continental break-up and is connected with the oldest supercontinental reconstruction (Ernst, 2016).</p><p>All studies have been supported by RFRB 18-05-70082, Scientific Research Contracts Nos 0226-2019-0032 and 0226-2019-0053.</p>

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