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Bauer, Tobias, Associate professorORCID iD iconorcid.org/0000-0003-1627-7058
Alternative names
Publications (10 of 47) Show all publications
Juanatey, M. A. G., Hübert, J., Tryggvason, A., Juhlin, C., Pedersen, L. B., Bauer, T. E. & Dehghannejad, M. (2019). 2D and 3D MT in the central Skellefte Ore District, northern Sweden. Tectonophysics, 764, 124-138
Open this publication in new window or tab >>2D and 3D MT in the central Skellefte Ore District, northern Sweden
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2019 (English)In: Tectonophysics, ISSN 0040-1951, E-ISSN 1879-3266, Vol. 764, p. 124-138Article in journal (Refereed) Published
Abstract [en]

New broadband magnetotelluric (MT) data have been acquired along two parallel profiles in the central part of the metallogenic Skellefte district in northern Sweden. The data were recorded as part of the Swedish 4D modelling of mineral belts project and cover an area with several economical and sub-economical deposits. The dimensionality and quality of the data were carefully analyzed and new error floors were systematically determined prior to inverse modelling in 2D and 3D. The algorithms used were EMILIA and WSINV3DMT. For the 2D inversion, only the determinant of the impedance tensor was used, while for the 3D inversion all elements were considered. The obtained models fit the inverted data, and image the main regional features. A detailed comparison reveals the superiority of the 3D model, both in model structures and data fit. After assessing the main features in the model, an interpretation is proposed and refined with the support of previous geophysical studies. The most interesting features are large and medium-sized conductors associated with crustal-scale shear zones and faults within the Skellefte Group rocks. These may be depicting a network of fossil pathways for hydrothermal fluid transport and as such, provide new insight into past processes in the area.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Magnetotellurics 3D inversion, Deep exploration, Brownfield, Shear zones, Mineral systems
National Category
Geology
Research subject
Ore Geology
Identifiers
urn:nbn:se:ltu:diva-73685 (URN)10.1016/j.tecto.2019.04.003 (DOI)000472697900008 ()2-s2.0-85066444822 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-06-27 (johcin)

Available from: 2019-04-17 Created: 2019-04-17 Last updated: 2019-08-15Bibliographically approved
Sarlus, Z., Martinsson, O., Bauer, T., Wanhainen, C., Andersson, J. & Nordin, R. (2019). Character and tectonic setting of plutonic rocks in the Gällivare area, northern Norrbotten, Sweden. GFF, 141(1), 1-20
Open this publication in new window or tab >>Character and tectonic setting of plutonic rocks in the Gällivare area, northern Norrbotten, Sweden
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2019 (English)In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 141, no 1, p. 1-20Article in journal (Refereed) Published
Abstract [en]

Petrographical and lithogeochemical investigations in combination with mapping in the Gällivare area, northern Norrbotten, Sweden, have led to the identification of several igneous intrusive rock types. These include: (1) ultramafic-mafic complexes, (2) mafic-intermediate rocks, (3) dolerites and (4) felsic plutons. The ultramafic-mafic rocks include the ca. 1.88 Ga Dundret complex and ca. 1.80 Ga Vassaravaara complex. The Dundret complex has tholeiitic to calc-alkaline affinity, shows a primitive mineral content and was formed in an extensional tectonic setting. The Vassaravaara complex has a similar chemical signature as the Dundret complex. The mafic-intermediate plutons vary in composition from gabbro to diorite. The chemical signature of the dioritic rocks indicate formation in a volcanic arc setting. Dolerites occur as solitary dikes and have calc-alkaline affinity. The felsic plutons include granite and syenite of ca. 1.88, 1.80 and 1.78 Ga age. The felsic plutons have calc-alkaline to shoshonitic affinity and mostly show a metaluminous I-type character. Results indicate subduction at 1.90 Ga resulting in a volcanic arc system, and including extensional events generating back-arc environments leading to mafic, intermediate and felsic magmatism in the Gällivare area. Subduction at 1.80 Ga is suggested to have caused a similar process generating mafic and felsic magmatic rocks in the same area. A subsequent collision event finally generated 1.78 Ga granitic rocks.

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
Gällivare area, mafic layered intrusions, petrography, lithogeochemistry, back-arc environment
National Category
Geology
Research subject
Ore Geology
Identifiers
urn:nbn:se:ltu:diva-69190 (URN)10.1080/11035897.2018.1526209 (DOI)000467182600001 ()
Note

Validerad;2019;Nivå 2;2019-06-18 (johcin)

Available from: 2018-06-08 Created: 2018-06-08 Last updated: 2019-06-18Bibliographically approved
Bauer, T., Andersson, J., Sarlus, Z., Lund, C. & Kearney, T. (2018). Structural controls on the setting, shape and hydrothermal alteration of the Malmberget IOA deposit, northern Sweden. Economic geology and the bulletin of the Society of Economic Geologists, 113(2), 377-395
Open this publication in new window or tab >>Structural controls on the setting, shape and hydrothermal alteration of the Malmberget IOA deposit, northern Sweden
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2018 (English)In: Economic geology and the bulletin of the Society of Economic Geologists, ISSN 0361-0128, E-ISSN 1554-0774, Vol. 113, no 2, p. 377-395Article in journal (Refereed) Published
Abstract [en]

The Malmberget iron oxide-apatite (IOA) deposit in northern Sweden is one of the largest underground iron ore mine operations in the world with estimated ore reserves in 2015 of 346 million metric tons (Mt) at 42.5% Fe. The underground operation is concentrated in 10 orebodies of 5 to 245 Mt each, which currently produce 17.4 Mt of apatite iron ore per year. Structural investigations were combined with data on hydrothermal mineral assemblages in order to reconstruct the relative timing of ore-forming, deformation, and overprinting hydrothermal events. The results improve the understanding of structural geometries, relationships, and control on orebody transposition in the deposit. A first compressional event (D1) around 1.88 Ga represents the main metamorphic event (M1) in the area and was responsible for a strong transposition of potential primary layering and the orebodies and led to the formation of a composite S0/1 fabric. A subsequent F2 folding event around 1.80 Ga resulted in the formation of an open, slightly asymmetric synform with a steeper southeast limb and a roughly SW-plunging fold axis. The result of structural modeling implies that the ore formed at two separate horizons. The folding was accompanied by stretching, resulting in boudinage of the iron orebodies. D2-related high-strain zones and syntectonic granites triggered the remobilization of amphibole, biotite, magnetite, and hematite and controlled the formation of iron oxide-copper-gold (IOCG)-type hydrothermal alteration, including an extensive K-feldspar alteration accompanied with sulfides, scapolite, and epidote. This shows a distinct time gap of at least 80 m.y. between the formation of iron oxides and sulfides. Brittle structures and the lack of an axial planar parallel fabric in conjunction with previous results suggest upper crustal, low-pressure, and high-temperature conditions during this D2 deformation phase, indicating a hydrothermal event rather than a purely regional metamorphic compression. It is proposed in the present study that the Malmberget IOA deposit was deformed and metamorphosed during a 1.88 Ga crustal shortening event. Moreover, the Malmberget IOA deposit was affected by a 1.8 Ga folding and hydrothermal event that is related to a regional IOCG overprint.

Place, publisher, year, edition, pages
Society of Economic Geologists, 2018
Keywords
Palaeoproterozoic, IOA, IOCG, deformation, 3D-modelling
National Category
Geology Metallurgy and Metallic Materials
Research subject
Ore Geology; Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-66455 (URN)10.5382/econgeo.2018.4554 (DOI)000429317200003 ()2-s2.0-85043379790 (Scopus ID)
Projects
Multi-scale 4-dimensional geological modeling of the Gällivare area
Note

Validerad;2018;Nivå 2;2018-03-19 (andbra)

Available from: 2017-11-08 Created: 2017-11-08 Last updated: 2018-11-19Bibliographically approved
Sarlus, Z., Andersson, U. B., Bauer, T. E., Wanhainen, C., Martinsson, O., Nordin, R. & Andersson, J. B. .. (2018). Timing of plutonism in the Gällivare area: mplications for Proterozoic crustal development in the northern Norrbotten ore district, Sweden. Geological Magazine, 155(6), 1351-1376
Open this publication in new window or tab >>Timing of plutonism in the Gällivare area: mplications for Proterozoic crustal development in the northern Norrbotten ore district, Sweden
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2018 (English)In: Geological Magazine, ISSN 0016-7568, E-ISSN 1469-5081, Vol. 155, no 6, p. 1351-1376Article in journal (Refereed) Published
Abstract [en]

Zircon ion probe (secondary-ion mass spectrometry or SIMS) data from a set of intrusive rocks emplaced in the vicinity of major ore bodies, as well as from large igneous intrusions in the Gällivare area, gave the following results: (1) the Dundret ultramafic–mafic layered complex (1883±5 Ma), the Aitik granite (1883±5 Ma), the Nautanen diorite (1870±12 Ma), the Vassaravaara ultramafic–mafic layered complex (1798±4 Ma), the Aitik dolerite (1813±9 Ma), the Bergmästergruvan and Sikträsk syenites (1795±4 Ma and 1801±3 Ma, respectively) and the Naalojärvi granite (1782±5 Ma). These data broadly fall within the ranges 1.89–1.87 Ga (early Svecofennian) and 1.80–1.78 Ga (late Svecofennian), but geochronologically allow further subdivision into pulses at 1885–1880, 1875–1870, 1800 and 1780 Ma. During these events, large layered ultramafic–mafic and felsic plutonic rocks were generated with distinct overlap in time suggesting coeval felsic–mafic magmatism. Results also indicate the presence of inherited c. 1.87 Ga zircon crystals in the plutonic rocks at 1.78 Ga, supporting reworking of the previous crust. These data indicate the importance of mantle-derived mafic underplating in the process of crustal magma generation in the region. The c. 1.88 Ga event that generated ultramafic–mafic layered complexes is tentatively suggested to have played an important role in the formation of the Aitik Cu–Au porphyry system. The later event at c. 1.80 Ga, generating voluminous mafic–felsic units, is suggested to be coupled to the regional iron-oxide-copper-gold (IOCG) overprint.

Place, publisher, year, edition, pages
Cambridge University Press, 2018
National Category
Geology
Research subject
Ore Geology
Identifiers
urn:nbn:se:ltu:diva-63390 (URN)10.1017/S0016756817000280 (DOI)000439690800008 ()2-s2.0-85018356169 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-07-26 (inah)

Available from: 2017-05-17 Created: 2017-05-17 Last updated: 2018-08-15Bibliographically approved
Zainy, M. T., Al-Ansari, N., Bauer, T. & Ask, M. (2017). The Tectonic and Structural Classifications of the Western Part of the Zagros Fold and Thrust Belt, North Iraq, Review and Discussion. Journal of Earth Sciences and Geotechnical Engineering, 7(2), 71-89
Open this publication in new window or tab >>The Tectonic and Structural Classifications of the Western Part of the Zagros Fold and Thrust Belt, North Iraq, Review and Discussion
2017 (English)In: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 7, no 2, p. 71-89Article in journal (Refereed) Published
Abstract [en]

The Zagros fold and thrust belt represents a tectonically significant area, and one of the richest areas in oil and gas reservoirs in the world. The Zagros fold and thrust belt is the deformational product of the Cretaceous-present day convergence of the Arabian and Iranian (Eurasian) plates (subduction and collision). The belt extends more than 2000 km from southern Turkey through the north and northeastern Iraq to the Strait of Hormuz in southwestern Iran. The Zagros fold and thrust belt is divided into two parts which are; Western part within Iraqi region and Eastern part within Iranian region. The western part of the Zagros fold and thrust belt has been traditionally subdivided into several structural zones that are generally striking parallel to the plate boundary. This is characterized by exposure of Late Ordovician to Pliocene - Pliestocene formations with different types of Quaternary Sediments. This research will concentrate on Western part of Zagros fold and thrust belt and the styles of structural classifications, which will aid to clarify and better understand the tectonic and structural history and evolution of the region. We have considered the last version of structural classification as the most relevant one to the reality, especially within outer platform (Unstable shelf). Where it divides the region into four structural zones, which are: Low Folded zone, High Folded Zone, Imbricate Zone, and Zagros Suture Zone and these zones were further divided to several subzones. This classification is based on the structural style and intensity of deformation, stratigraphy, mechanicalstratigraphy and tectono-stratigraphy of the deformed sequences, Age of deformation, surface physiography and morphology. The data used in the classification is more reliable, up to date and relevant.

Place, publisher, year, edition, pages
ScienPress Ltd, 2017
Keywords
Tectonic, Classification, Western Zagros Belt, North Iraq
National Category
Geology Geotechnical Engineering
Research subject
Applied Geology; Soil Mechanics
Identifiers
urn:nbn:se:ltu:diva-61884 (URN)
Note

Validerad; 2017; Nivå 1; 2017-02-15 (andbra)

Available from: 2017-02-09 Created: 2017-02-09 Last updated: 2018-11-15Bibliographically approved
Zainy, M., Al-Ansari, N., Bauer, T. & Ask, M. (2017). The Tectonic and Structural Classifications of the Western Part of the Zagros Fold and Thrust Belt, North Iraq, Review and Discussion. Journal of Earth Sciences and Geotechnical Engineering, 7(2), 71-89
Open this publication in new window or tab >>The Tectonic and Structural Classifications of the Western Part of the Zagros Fold and Thrust Belt, North Iraq, Review and Discussion
2017 (English)In: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, Vol. 7, no 2, p. 71-89Article in journal (Refereed) Published
Abstract [en]

The Zagros fold and thrust belt represents a tectonically significant area, and one

of the richest areas in oil and gas reservoirs in the world. The Zagros fold and

thrust belt is the deformational product of the Cretaceous-present day convergence

of the Arabian and Iranian (Eurasian) plates (subduction and collision). The belt

extends more than 2000 km from southern Turkey through the north and

northeastern Iraq to the Strait of Hormuz in southwestern Iran. The Zagros fold

and thrust belt is divided into two parts which are; Western part within Iraqi

region and Eastern part within Iranian region. The western part of the Zagros fold

and thrust belt has been traditionally subdivided into several structural zones that

are generally striking parallel to the plate boundary. This is characterized by

exposure of Late Ordovician to Pliocene - Pliestocene formations with different

types of Quaternary Sediments. This research will concentrate on Western part of

Zagros fold and thrust belt and the styles of structural classifications, which will

aid to clarify and better understand the tectonic and structural history and

evolution of the region. We have considered the last version of structural

classification as the most relevant one to the reality, especially within outer

platform (Unstable shelf). Where it divides the region into four structural zones,

which are: Low Folded zone, High Folded Zone, Imbricate Zone, and Zagros

Suture Zone and these zones were further divided to several subzones. This

classification is based on the structural style and intensity of deformation,

stratigraphy, mechanicalstratigraphy and tectono-stratigraphy of the deformed

sequences, Age of deformation, surface physiography and morphology. The data

used in the classification is more reliable, up to date and relevant.

Place, publisher, year, edition, pages
New Zealand: Scienpress Ltd, 2017
Keywords
Tectonic, Classification, Western Zagros Belt, North Iraq
National Category
Geology Geochemistry Geotechnical Engineering
Research subject
Applied Geology; Ore Geology; Soil Mechanics; Applied Geochemistry
Identifiers
urn:nbn:se:ltu:diva-75084 (URN)
Available from: 2019-06-27 Created: 2019-06-27 Last updated: 2019-07-08Bibliographically approved
Andersson, J. B. .., Bauer, T. E., Martinsson, O. & Wanhainen, C. (2017). The tectonic overprint on the Per Geijer apatite iron ores in Kiruna, northern Sweden. In: Mercier Langevin, P; Dube, B; Bardoux, M; Ross, PS; Dion, C (Ed.), Mineral Resources to Discover: . Paper presented at 14th SGA Biennial Meeting on Mineral Resources to Discover, Quebec City, Canada, AUG 20-23, 2017 (pp. 903-906). Society for Geology Applied to Mineral Deposits
Open this publication in new window or tab >>The tectonic overprint on the Per Geijer apatite iron ores in Kiruna, northern Sweden
2017 (English)In: Mineral Resources to Discover / [ed] Mercier Langevin, P; Dube, B; Bardoux, M; Ross, PS; Dion, C, Society for Geology Applied to Mineral Deposits , 2017, p. 903-906Conference paper, Published paper (Refereed)
Abstract [en]

This ongoing project focusses on the structural evolution of the Per Geijer apatite iron ores in Kiruna, northern Sweden. The Per Geijer iron ores are situated in a NNE-SSW trending shear zone. This study indicate that the shear zone was active during D2 E-W compression giving rise to dip-slip and oblique slip components. The ductile fabric is overprinted by brittle structures carrying Cu, possibly representing traces of a separate Iron Oxide Copper Gold event in northern Norrbotten.

Place, publisher, year, edition, pages
Society for Geology Applied to Mineral Deposits, 2017
National Category
Geology
Research subject
Ore Geology
Identifiers
urn:nbn:se:ltu:diva-70285 (URN)000439764100223 ()978-2-9816898-0-1 (ISBN)
Conference
14th SGA Biennial Meeting on Mineral Resources to Discover, Quebec City, Canada, AUG 20-23, 2017
Available from: 2018-08-09 Created: 2018-08-09 Last updated: 2019-08-15Bibliographically approved
Sarlus, Z., Martinsson, O., Bauer, T. E. & Wanhainen, C. (2017). Timing and tectonic setting of host rocks to the Malmberget AlO deposit, Sweden. In: Mercier Langevin, P; Dube, B; Bardoux, M; Ross, PS; Dion, C (Ed.), Mineral Resources to Discover: . Paper presented at 14th SGA Biennial Meeting on Mineral Resources to Discover, Quebec City, Canada, AUG 20-23, 2017 (pp. 959-962). Society for Geology Applied to Mineral Deposits
Open this publication in new window or tab >>Timing and tectonic setting of host rocks to the Malmberget AlO deposit, Sweden
2017 (English)In: Mineral Resources to Discover / [ed] Mercier Langevin, P; Dube, B; Bardoux, M; Ross, PS; Dion, C, Society for Geology Applied to Mineral Deposits , 2017, p. 959-962Conference paper, Published paper (Refereed)
Abstract [en]

Host felsic and intermediate meta-volcanic rocks to the Malmberget apatite iron ore (AlO) deposit have been investigated geochemically and geochronologically, the latter using the U-Pb method on a set of zircons. Results indicate emplacement age of 1.9 Ga for the felsic and intermediate volcanic rocks, potentially in an extensional environment. The zircon U-Pb radiometric ages are among the first conclusive ages with implicit constraint on the geological evolution of the northern Norrbotten ore district and Malmberget deposit.

Place, publisher, year, edition, pages
Society for Geology Applied to Mineral Deposits, 2017
National Category
Geology
Research subject
Ore Geology; Ore Geology
Identifiers
urn:nbn:se:ltu:diva-70281 (URN)000439764100237 ()978-2-9816898-0-1 (ISBN)
Conference
14th SGA Biennial Meeting on Mineral Resources to Discover, Quebec City, Canada, AUG 20-23, 2017
Available from: 2018-08-09 Created: 2018-08-09 Last updated: 2018-08-09Bibliographically approved
Tavakoli, S., Bauer, T., Rasmussen, T. M., Weihed, P. & Elming, S.-å. (2016). Deep massive sulphide exploration using 2D and 3D geoelectrical and induced polarization data in Skellefte mining district, northern Sweden (ed.). Geophysical Prospecting, 64(6), 1602-1619
Open this publication in new window or tab >>Deep massive sulphide exploration using 2D and 3D geoelectrical and induced polarization data in Skellefte mining district, northern Sweden
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2016 (English)In: Geophysical Prospecting, ISSN 0016-8025, E-ISSN 1365-2478, Vol. 64, no 6, p. 1602-1619Article in journal (Refereed) Published
Abstract [en]

Geoelectrical and induced polarization data from measurements along three profiles and from one 3D survey are acquired and processed in the central Skellefte District, northern Sweden. The data were collected during two field campaigns in 2009 and 2010 in order to delineate the structures related to volcanogenic massive sulphide deposits and to model lithological contacts down to a maximum depth of 1.5 km. The 2009 data were inverted previously, and their joint interpretation with potential field data indicated several anomalous zones. The 2010 data not only provide additional information from greater depths compared with the 2009 data but also cover a larger surface area. Several high-chargeability low-resistivity zones, interpreted as possible massive sulphide mineralization and associated hydrothermal alteration, are revealed. The 3D survey data provide a detailed high-resolution image of the top ∼450 m of the upper crust around the Maurliden East, North, and Central deposits. Several anomalies are interpreted as new potential prospects in the Maurliden area, which are mainly concentrated in the central conductive zone. In addition, the contact relationship between the major geological units, e.g., the contact between the Skellefte Group and the Jörn Intrusive Complex, is better understood with the help of 2010 deep-resistivity/chargeability data. The bottommost part of the Vargfors basin is imaged using the 2010 geoelectrical and induced polarization data down to ∼1-km depth.

National Category
Geophysics Geology
Research subject
Exploration Geophysics; Ore Geology
Identifiers
urn:nbn:se:ltu:diva-15251 (URN)10.1111/1365-2478.12363 (DOI)000386158100014 ()2-s2.0-84961572568 (Scopus ID)ebf80035-8141-4c62-94db-d97a3d1a5641 (Local ID)ebf80035-8141-4c62-94db-d97a3d1a5641 (Archive number)ebf80035-8141-4c62-94db-d97a3d1a5641 (OAI)
Note

Validerad; 2016; Nivå 2; 2016-11-21 (andbra)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Brethes, A., Guarnieri, P., Rasmussen, T. M. & Bauer, T. (2016). Geological Analysis of Aeromagnetic Data over the Blyklippen Lead-zinc Mine at Mesters Vig, Central East Greenland. In: First Conference on Geophysics for Mineral Exploration and Mining: Near Surface Geoscience 2016, Barcelona, Spain, 4-8 September 2016. Paper presented at 1st Conference on Geophysics for Mineral Exploration and Mining, Barcelona, Spain, 4-8 September 2016. Houten, Article ID Mo MIN 05.
Open this publication in new window or tab >>Geological Analysis of Aeromagnetic Data over the Blyklippen Lead-zinc Mine at Mesters Vig, Central East Greenland
2016 (English)In: First Conference on Geophysics for Mineral Exploration and Mining: Near Surface Geoscience 2016, Barcelona, Spain, 4-8 September 2016, Houten, 2016, article id Mo MIN 05Conference paper, Published paper (Refereed)
Abstract [en]

In the Mesters Vig area epithermal Pb-Zn sulphide-bearing quartz veins are associated with the border faults of a NNW-SSE elongated graben down-faulting Carboniferous to Lower Triassic sediments. The analysis of the total magnetic field, tilt derivative, vertical derivative and analytic signal allowed to define subcropping magnetic domains and identify structural trends. Doleritic dykes, sills and faults were mapped and structural relationships were established between them. Finally, aeromagnetic data allowed here to delineate structural trends along and in the vicinity of which mineralized quartz veins are mapped.

Place, publisher, year, edition, pages
Houten: , 2016
Keywords
aeromagnetic, lead, zinc
National Category
Geophysics Geology
Research subject
Exploration Geophysics; Ore Geology
Identifiers
urn:nbn:se:ltu:diva-60806 (URN)2-s2.0-85007285687 (Scopus ID)9789462821958 (ISBN)
Conference
1st Conference on Geophysics for Mineral Exploration and Mining, Barcelona, Spain, 4-8 September 2016
Projects
CRUS3D Nordmin
Funder
Nordic Council of Ministers
Available from: 2016-11-29 Created: 2016-11-29 Last updated: 2018-02-15Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-1627-7058

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