Geochemical Reconstruction of the Provenance, Tectonic Setting and Paleoweathering of Lower Paleozoic Black Shales from Northern Europe

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Geochemical Reconstruction of the Provenance, Tectonic Setting and Paleoweathering of Lower Paleozoic Black Shales from Northern Europe. / Ofili, Sylvester; Soesoo, Alvar; Panova, Elena; Hints, Rutt; Hade, Sigrid; Ainsaar, Leho.

In: Minerals, Vol. 12, No. 5, 602, 10.05.2022.

Research output: Contribution to journal › Article › peer-review

BibTeX

@article{4ad0f3528652449d942befa471ac39a1,

title = "Geochemical Reconstruction of the Provenance, Tectonic Setting and Paleoweathering of Lower Paleozoic Black Shales from Northern Europe",

abstract = "Lower Paleozoic black shales from Estonia, Sweden, and Russia were analyzed for major and trace elements to reconstruct the provenance, tectonic setting, and paleoweathering conditions of these shales. The black shale is highly enriched in U, V, Mo, and Pb (except in samples from Sweden where Pb is slightly enriched), slightly enriched in SiO2, Fe2O3, K2O, and TiO2 and highlydepleted in CaO, Na2O, and MnO, with respect to average shales. The provenance signatures (Th/Sc versus Zr/Sc, Al2O3 versus TiO2, Zr versus TiO2 plots, and Zr/Sc ratio) of the Baltoscandian black shales suggest that they were derived from rocks of intermediate to felsic composition and fromrecycled sediments. The likely provenance region was the Paleoproterozoic igneous and metamorphic basement of southern central and southern Finland, which consists predominantly of felsic to intermediate metamorphic (acidic to intermediate gneisses, felsic volcanics, microcline granites and migmatites) and igneous rocks (small granitic intrusions and large rapakivi granite intrusions), and reworked older Ediacaran and Lower Cambrian sediments; however, the proportion of clastic input from these sources is not uniform in the three regions studied. The discrimination of the tectonic settings of source materials of the black shale using the SiO2 versusK2O/Na2O plot and a new discriminant method (APMdisc) favors a passive margin setting. The Chemical Index of Weathering (CIW) indicates that the clastic material in the black shale of the studied regions has experienced an intense degree of chemical weathering. Weathering indices(Chemical Index of Alteration CIA and CIW) also show that the black shale has experienced significant secondary potassium enrichment.",

keywords = "Dictyonema shale, alum shale, black shale, graptolite argillite, paleoweathering, provenance, tectonic setting",

author = "Sylvester Ofili and Alvar Soesoo and Elena Panova and Rutt Hints and Sigrid Hade and Leho Ainsaar",

note = "Publisher Copyright: {\textcopyright} 2022 by the authors. Licensee MDPI, Basel, Switzerland.",

year = "2022",

month = may,

day = "10",

doi = "10.3390/min12050602",

language = "English",

volume = "12",

journal = "Minerals",

issn = "2075-163X",

publisher = "MDPI AG",

number = "5",

}

RIS

TY - JOUR

T1 - Geochemical Reconstruction of the Provenance, Tectonic Setting and Paleoweathering of Lower Paleozoic Black Shales from Northern Europe

AU - Ofili, Sylvester

AU - Soesoo, Alvar

AU - Panova, Elena

AU - Hints, Rutt

AU - Hade, Sigrid

AU - Ainsaar, Leho

PY - 2022/5/10

Y1 - 2022/5/10

N2 - Lower Paleozoic black shales from Estonia, Sweden, and Russia were analyzed for major and trace elements to reconstruct the provenance, tectonic setting, and paleoweathering conditions of these shales. The black shale is highly enriched in U, V, Mo, and Pb (except in samples from Sweden where Pb is slightly enriched), slightly enriched in SiO2, Fe2O3, K2O, and TiO2 and highlydepleted in CaO, Na2O, and MnO, with respect to average shales. The provenance signatures (Th/Sc versus Zr/Sc, Al2O3 versus TiO2, Zr versus TiO2 plots, and Zr/Sc ratio) of the Baltoscandian black shales suggest that they were derived from rocks of intermediate to felsic composition and fromrecycled sediments. The likely provenance region was the Paleoproterozoic igneous and metamorphic basement of southern central and southern Finland, which consists predominantly of felsic to intermediate metamorphic (acidic to intermediate gneisses, felsic volcanics, microcline granites and migmatites) and igneous rocks (small granitic intrusions and large rapakivi granite intrusions), and reworked older Ediacaran and Lower Cambrian sediments; however, the proportion of clastic input from these sources is not uniform in the three regions studied. The discrimination of the tectonic settings of source materials of the black shale using the SiO2 versusK2O/Na2O plot and a new discriminant method (APMdisc) favors a passive margin setting. The Chemical Index of Weathering (CIW) indicates that the clastic material in the black shale of the studied regions has experienced an intense degree of chemical weathering. Weathering indices(Chemical Index of Alteration CIA and CIW) also show that the black shale has experienced significant secondary potassium enrichment.

AB - Lower Paleozoic black shales from Estonia, Sweden, and Russia were analyzed for major and trace elements to reconstruct the provenance, tectonic setting, and paleoweathering conditions of these shales. The black shale is highly enriched in U, V, Mo, and Pb (except in samples from Sweden where Pb is slightly enriched), slightly enriched in SiO2, Fe2O3, K2O, and TiO2 and highlydepleted in CaO, Na2O, and MnO, with respect to average shales. The provenance signatures (Th/Sc versus Zr/Sc, Al2O3 versus TiO2, Zr versus TiO2 plots, and Zr/Sc ratio) of the Baltoscandian black shales suggest that they were derived from rocks of intermediate to felsic composition and fromrecycled sediments. The likely provenance region was the Paleoproterozoic igneous and metamorphic basement of southern central and southern Finland, which consists predominantly of felsic to intermediate metamorphic (acidic to intermediate gneisses, felsic volcanics, microcline granites and migmatites) and igneous rocks (small granitic intrusions and large rapakivi granite intrusions), and reworked older Ediacaran and Lower Cambrian sediments; however, the proportion of clastic input from these sources is not uniform in the three regions studied. The discrimination of the tectonic settings of source materials of the black shale using the SiO2 versusK2O/Na2O plot and a new discriminant method (APMdisc) favors a passive margin setting. The Chemical Index of Weathering (CIW) indicates that the clastic material in the black shale of the studied regions has experienced an intense degree of chemical weathering. Weathering indices(Chemical Index of Alteration CIA and CIW) also show that the black shale has experienced significant secondary potassium enrichment.

KW - Dictyonema shale

KW - alum shale

KW - black shale

KW - graptolite argillite

KW - paleoweathering

KW - provenance

KW - tectonic setting

UR - http://www.scopus.com/inward/record.url?scp=85129730644&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/acd22fa1-c9bb-3584-82d0-1a5653c1bc9e/

U2 - 10.3390/min12050602

DO - 10.3390/min12050602

M3 - Article

VL - 12

JO - Minerals

JF - Minerals

SN - 2075-163X

IS - 5

M1 - 602

ER -

ID: 95123849