Land‐derived palynomorphs from the Silurian of Gotland, Sweden

Abstract

A rich and well preserved acid resistant microflora of both marine and continental derivation is found in the Gotland sequence. The samples were obtained from two cores and a number of outcrops spanning the time interval Middle Llandovery‐Late Ludlow. Palynofacies analysis confirms that the entire Gotland sequence consists of sediments deposited under marine conditions. In the Ludfordian Burgsvik Beds (kozlowskii graptolite Biozone/Bohemograptus Proliferation Zone) the continental input is substantial and land‐derived palynomorphs constitute about 60% of the palynoflora whereas the older and younger Silurian deposits almost exclusively contain marine palynomorphs. Correlation with microfloras outside Baltica is hampered by the lack of diagnostic species in common with other areas. However, the sculpture of the Burgsvik spores had reached a level of complexity characteristic for the Ludfordian. Twenty three species of trilete spores and cryptospores have been recognized, including one new genus and three new species (Acontotetras gotlandica sp. nov., Pachytetras rugosa gen. et sp. nov., and Apiculiretusisporal burgsvikensis sp. nov.). In addition, fungal spores and hyphae, tubes, cuticles, and incertae sedis are reported.

Hagström, J., 1997: Land‐derived palynomorphs from the Silurian of Goüand, Sweden. GFF, Vol. 119 (Pt. 4, December), pp. 301–316. Stockholm. ISSN 1103–5897.

Keywords:

• Palynomorphs
• trilete spores
• cryptospores
• Sweden
• Gotland
• Burgsvik Beds
• Silurian
• biostratigraphy
• palynofacies