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- Mekhonoshin, A. S., et al.
(author)
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Relationship between platinum-bearing ultramafic-mafic intrusions and large igneous provinces (exemplified by the Siberian Craton)
- 2016
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In: Russian Geology and Geophysics. - : GeoScienceWorld. - 1068-7971. ; 57:5, s. 822-833
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Journal article (peer-reviewed)abstract
- This study aims at summarizing available geological and geochemical data on known Proterozoic platinum-bearing ultramafic-mafic massifs in the south of Siberia. Considering new data on geochemistry and geochronology of some intrusions, it was feasible to compare ore-bearing complexes of different time spans and areas and to follow their relationships with the recognized large igneous provinces. In the south of Siberia, the platinum-bearing massifs might be united into three age groups: Late Paleoproterozoic (e.g., Chiney complex, Malozadoisky massif), Late Mesoproterozoic (e.g., Srednecheremshansky massif), and Neoproterozoic (e.g., Kingash complex, Yoko-Dovyren massif, and massifs in the center of the East Sayan Mts.). In most massifs but Chiney the initial magmas are magnesium-rich. On paleogeodynamic reconstructions, the position of the studied massifs is the evidence that three most precisely dated events in North Canada continued into southern Siberia: In the period 1880-1865 Ma, it was the Ghost-Mara River-Morel LIP; at 1270-1260 Ma, the Mackenzie LIP; and at 725-720 Ma, Franklin LIP. In Siberia, the mostly productive massifs with respect to PGE-Ni-Cu mineralization are those linked with the Franklin LIP: Verkhny Kingash, Yoko-Dovyren, and central part of the Eastern Sayan Mountains, e.g., Tartay, Zhelos, and Tokty-Oy.
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| 2. |
- Podsiadlo, P., et al.
(author)
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Baseline trabecular bone and its relation to incident radiographic knee osteoarthritis and increase in joint space narrowing score : directional fractal signature analysis in the MOST study
- 2016
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In: Osteoarthritis and Cartilage. - : Elsevier BV. - 1063-4584. ; 24:10, s. 1736-1744
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Journal article (peer-reviewed)abstract
- Purpose To explore the association of baseline trabecular bone structure with incident tibiofemoral (TF) osteoarthritis (OA) and with increase in joint space narrowing (JSN) score. Methods The Multicenter Osteoarthritis Study (MOST) includes subjects with or at risk for knee OA. Knee radiographs were scored for Kellgren–Lawrence (KL) grade and JSN at baseline, 30, 60 and 84 months. Knees (KL ≤ 1) at baseline were assessed for incident OA (KL ≥ 2) and increases in JSN score. For each knee image at baseline, a variance orientation transform method (VOT) was applied to subchondral tibial bone regions of medial and lateral compartments. Seventeen fractal parameters were calculated per region. Associations of each parameter with OA incidence and with medial and lateral JSN increases were explored using logistic regression. Analyses were stratified by digitized film (DF) vs computer radiography (CR) and adjusted for confounders. Results Of 894 knees with CR and 1158 knees with DF, 195 (22%) and 303 (26%) developed incident OA. Higher medial bone roughness was associated with increased odds of OA incidence at 60 and 84 months and also, medial and lateral JSN increases (primarily vertical). Lower medial and lateral anisotropy was associated with increased odds of medial and lateral JSN increase. Compared to DF, CR had more associations and also, similar results at overlapping scales. Conclusion Baseline trabecular bone texture was associated with incident radiographic OA and increase of JSN scores independently of risk factors for knee OA. Higher roughness and lower anisotropy were associated with increased odds for radiographic OA change.
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