Integrated Telychian (Silurian) K-bentonite chemostratigraphy and biostratigraphy in Estonia and Latvia

Abstract

Kiipli, T., Kallaste, T., Nestor, V. & Loydell, D.K. 2010: Integrated Telychian (Silurian) K‐bentonite chemostratigraphy and biostratigraphy in Estonia and Latvia. Lethaia, Vol. 43, pp. 32–44. The distribution of altered volcanic ash layers (K‐bentonites) and Telychian chitinozoans in four East Baltic drill core sections are compared. This information is integrated with graptolite and conodont biozonations to give a precise correlation chart using four different stratigraphical tools: K‐bentonite‐based chemostratigraphy; chitinozoan biostratigraphy; graptolite biostratigraphy; and, conodont biostratigraphy. Thickness variations in the K‐bentonites suggest that the source of the volcanic ash was to the west and north‐west.

Correlation of upper Llandovery–lower Wenlock bentonites in the När (Gotland, Sweden) and Ventspils (Latvia) drill cores: role of volcanic ash clouds and shelf sea currents in determining areal distribution of bentonite

“…The distribution areas composed by Kiipli et al (2008bKiipli et al ( , 2008cKiipli et al ( , 2008dKiipli et al ( , 2010b for ca 20 bentonites in the eastern Baltic indicate ash transport from the northwest in terms of the present-day orientation of Europe. Correlation with the När section enables extension of the bentonite distribution areas for the Ireviken, Lusklint, Ohesaare and Aizpute bentonites (Fig.…”

“…Batchelor & Weir 1988;Batchelor 2009). In the East Baltic area ash beds from a total of 51 volcanic eruptions have been identified in the Telychian (Kiipli et al 2008b(Kiipli et al , 2008c(Kiipli et al , 2008d(Kiipli et al , 2010b and 55 in the Wenlock (Kiipli et al 2010a). Several ash beds are known in the lower Ludlow (Kiipli et al 2011), but these are very rare in younger sedimentary rocks.…”

Geochemistry and correlation of volcanic ash beds from the Rootsiküla Stage (Wenlock–Ludlow) in the eastern Baltic

“…Volcanic ash beds altered to clay (bentonites, K-bentonites) in Silurian sections have been successfully applied in stratigraphy as perfect time markers for correlation (Batchelor 2009;Inanli et al 2009;Kiipli et al , 2008aKiipli et al , 2010b. For identification of a particular eruption bed the composition of apatite (Ray 2007;Carey et al 2009), biotite (Batchelor 2003) and sanidine phenocrysts (Kiipli & Kallaste 2002), the specific shape of phenocrysts (Kiipli et al 2009) and immobile trace elements (Huff et al 1998;Kiipli et al 2008b) have been used.…”

Geochemical variations within the mid-Silurian Grötlingbo Bentonite (Gotland, Sweden): discriminating between magmatic composition, ash transport fractionation and diagenetic effects

“…Volcanic ash beds in sedimentary successions have frequently been used for precise regional correlation of sedimentary sections (Bergström et al 1995;Kiipli et al 2008aKiipli et al , 2010aKiipli et al , 2010bRay et al 2011;Cramer et al 2012) and for reconstruction of the tectonomagmatic environments in volcanic source areas (Batchelor 2009;Hetherington et al 2011). Various methods for such fingerprinting exist, and the composition of magmatic phenocrysts apatite (Batchelor et al 1995;Ray 2007;Sell & Samson 2011), biotite (Batchelor 2003) and sanidine (Kiipli & Kallaste 2002) and trace element characteristics (Batchelor & Jeppson 1999;Batchelor & Evans 2000;Huff et al 2000;Inanli et al 2009;Kiipli et al 2008b) have all been used for characterisation and interpretation of ash beds.…”