TY - JOUR

T1 - Biozonation of the furongian (upper Cambrian) alum shale formation at Hunneberg, Sweden

AU - Rasmussen, Bo Wilhelm

AU - Rasmussen, Jan Audun Liljeroth

AU - Nielsen, Arne Thorshøj

PY - 2016

Y1 - 2016

N2 - The Furongian Alum Shale at Nygård, Hunneberg, Sweden, has been sampled for trilobites.The section is ≥12.20 m thick and comprises a relatively thick Olenus superzone, overlain by morecondensed Parabolina, Leptoplastus, Protopeltura and Peltura superzones. The section is truncated lowin the Peltura superzone, presumably due to late Furongian uplift. The internal zonation of the sparselyfossiliferous Olenus superzone is unsettled. Above that level, the Parabolina spinulosa, Leptoplastuscrassicornis–Leptoplastus angustatus, Sphaerophthalmus flagellifer, Ctenopyge similis, Ctenopygespectabilis, Ctenopyge tumida and Ctenopyge bisulcata zones are documented. The C. similis–C. spectabilis zonal interval yielded a lower faunal assemblage with Ctenopyge (Mesoctenopyge) erecta,Sphaeropthalmus modestus and Ctenopyge (M.) spectabilis and an upper assemblage with Ctenopyge(M.) similis, Sphaeropthalmus angustus and Protopeltura planicauda. Hence, the FAD’s of C. (M.) similisand C. (M.) spectabilis are opposite of the previously described pattern. We informally refer to the lowerassemblage as the S. modestus biozone and to the upper assemblage as the S. angustus biozone (believedto be equivalent to the C. similis and C. spectabilis chronozones, respectively). It is possible that the truerange of the rare species C. (M.) similis has to date escaped recognition. Alternatively, if the existingchronozonation is correct, this implies reworking and the discussed interval at Nygård must in that caserepresent the C. spectabilis Zone. Ctenopyge (Ctenopyge) bisulcata, C. (M.) similis, C. (M.) spectabilis,L. angustatus, L. crassicornis, Leptoplastus paucisegmentatus?, Peltura scarabaeoides scarabaeoides,Peltura planicauda, Sphaerophthalmus alatus, Sphaerophthalmus drytonensis, S. modestus, Triangulopygehumilis and Triangulopyge majusculus have not previously been reported from the locality.

AB - The Furongian Alum Shale at Nygård, Hunneberg, Sweden, has been sampled for trilobites.The section is ≥12.20 m thick and comprises a relatively thick Olenus superzone, overlain by morecondensed Parabolina, Leptoplastus, Protopeltura and Peltura superzones. The section is truncated lowin the Peltura superzone, presumably due to late Furongian uplift. The internal zonation of the sparselyfossiliferous Olenus superzone is unsettled. Above that level, the Parabolina spinulosa, Leptoplastuscrassicornis–Leptoplastus angustatus, Sphaerophthalmus flagellifer, Ctenopyge similis, Ctenopygespectabilis, Ctenopyge tumida and Ctenopyge bisulcata zones are documented. The C. similis–C. spectabilis zonal interval yielded a lower faunal assemblage with Ctenopyge (Mesoctenopyge) erecta,Sphaeropthalmus modestus and Ctenopyge (M.) spectabilis and an upper assemblage with Ctenopyge(M.) similis, Sphaeropthalmus angustus and Protopeltura planicauda. Hence, the FAD’s of C. (M.) similisand C. (M.) spectabilis are opposite of the previously described pattern. We informally refer to the lowerassemblage as the S. modestus biozone and to the upper assemblage as the S. angustus biozone (believedto be equivalent to the C. similis and C. spectabilis chronozones, respectively). It is possible that the truerange of the rare species C. (M.) similis has to date escaped recognition. Alternatively, if the existingchronozonation is correct, this implies reworking and the discussed interval at Nygård must in that caserepresent the C. spectabilis Zone. Ctenopyge (Ctenopyge) bisulcata, C. (M.) similis, C. (M.) spectabilis,L. angustatus, L. crassicornis, Leptoplastus paucisegmentatus?, Peltura scarabaeoides scarabaeoides,Peltura planicauda, Sphaerophthalmus alatus, Sphaerophthalmus drytonensis, S. modestus, Triangulopygehumilis and Triangulopyge majusculus have not previously been reported from the locality.

KW - Faculty of Science

KW - Cambrian

KW - Furongian

KW - alum shale

KW - biostratigraphy

KW - trilobites;

KW - Sweden

KW - Scandinavia

U2 - 10.1080/11035897.2016.1168866

DO - 10.1080/11035897.2016.1168866

M3 - Journal article

VL - 138

SP - 467

EP - 489

JO - G F F

JF - G F F

SN - 1103-5897

IS - 4

ER -