Updating Frasnian miospore zonation from the Boulonnais (Northern France) and comparison with new data from the Upper Palaeozoic cover on the Brabant Massif (Western Belgium)

Abstract

Accurate palyno-analysis by S. Loboziak (from 1980 to 1983) of 28 samples from the Upper Givetian to the Middle Frasnian Blacourt, Beaulieu and Ferques Formations and of 44 samples of the Upper Frasnian to the Lower Famennian Hydrequent Formation are re-evaluated. Chelinospora concinna, Verrucosisporites bulliferus, Cirratriradites jekhowskyi, Lophozonotriletes media first occurrences are major criteria for Lower and Middle Frasnian, well calibrated by conodonts. Cymbosporites acanthaceus, Rugospora bricei, Grandispora gracilis, Diducites plicabilis, Corbulispora vimineus first occurrences allow to subdivide the Upper Frasnian where conodonts are poorly present. Samarisporites triangulatus versus Auroraspora pseudocrista taxonomy and stratigraphic significance are discussed. The reconnaissance borehole Nieuwkerke-De Seule (95W152), near the limit of the Upper Palaeozoic subcrop on the Brabant Massif (West Flanders, Belgium, 75 km east of the Boulonnais), which has intersected conodont-dated Givetian/Frasnian boundary at the transition between the Bois de Bordeaux and Bovesse Formations, contained poorly preserved miospores attributed to the triangulatus–concinna (TCo) Oppel Zones. In the nearby Nieuwkerke-Noordhoek borehole (95W153), strata also assigned to the Bovesse Formation yielded better preserved miospores which demonstrate a close succession of triangulatus–concinna (TCo) and bulliferus–jekhowskyi (BJ) Oppel Zones at the transition Lower–Middle Frasnian, also known in the Beaulieu Formation in the Boulonnais. Samples from the Heuvelland groundwater monitoring well (95W175), 10 km north of Nieuwkerke, contain the bricei-acanthaceus (BA) Oppel Zone suggesting a late Frasnian age, also known in the Hydrequent Formation in the Boulonnais area and in the Booischot Formation in the Booischot borehole (59E146) from the Campine Basin (Belgium). International correlation using Frasnian miospore zonation is attempted between the Pripyat Depression in Belarus, the Timan–Pechora province in Russia and North-West China.

Palynology and geochemistry of the Frasnian global transgression in the Parnaíba Basin, Brazil

“…Givetian to Lower Famennian deposits, containing miospores, are widespread on the territory of the Pripyat Depression in SE Belarus and the Timan-Pechora Province in Russia. The biostratigraphy of these deposits is based also on conodonts in the Timan-Pechora Streel et al, 2021. Correlations during the Late Givetian to Middle Frasnian between Boulonnais and Eastern Europe are shown to be obvious from varcus to punctata conodont Zones. They are less obvious from the Middle Frasnian to the Early Famennian (Obukhovskaya, 2000;Streel et al, 2000b;Telnova, 2008;Telnova et al, 2019).…”

“…Restudy of this data and new samples collected in boreholes from neighboring Flanders (Belgium) allow for better characterization of the transition from Middle to Lowermost Famennian and a comparison with contemporary Eastern Europe miospores based zonations. (Streel et al, 2021). The correlation at the BM/BA transition dated Plate X. Miospores: Specimens are located according the sample number and the England finders coordinates.…”

“…Despite their relative abundance, they all agree with regard to dating the geochemichal events of an equivalent Frasnian age. New observations in Brazil and new data from the Boulonnais Area, Northern France (Streel et al, 2021) have made it possible to correlate the Brazilian outcrops with the European conodont zones and therefore with the stratotypes of the Frasnian.…”

The pre-Taghanic (Givetian, Middle Devonian) ecosystems of Miłoszów (Holy Cross Mts, Poland)

“…According to Turnau (2011), this miospore taxon disappears within the Ex2 Subzone; as a consequence, its presence indicates Ex2 as the youngest possible subzone for these samples. This result must be treated with caution as samples 8A, 8B, 10B, 10C and 10D contained miospores that strongly resemble Samarisporites triangulatus, which is the index taxon for the Ex3 Subzone; moreover, C. concinna may range to the Late Givetian (Streel et al, 2021).…”

The first finding of <i>Skeletognathus norrisi</i> in association with higher plant spores and brachiopods in the Givetian-Frasnian boundary deposits drilled by borehole No. 8 Tsarichanskaya (East Orenburg uplift, Russian Platform)

“…Выделенный ПС соответствует по таксономи ческому составу палинокомплексу (ПК) из верхней части тиманской свиты в стратотипическом разре зе на Южном Тимане (Тельнова, 2007). В разрезах Западной Европы ПК, подобный описанному ПК из керна скважины № 8 Царичанская, соответству ет верхней части оппель-зоны triangulatus-concinna (TCo), охватывающей пограничный живетскофранский интервал (Streel et al, 2021).…”