New miospore data from the Namurian Biały Kamień Formation in the northern part of the Intra-Sudetic Basin (SW Poland)

Abstract

Palynostratigraphic studies of the Carboniferous strata of the Biały Kamień Formation, outcropping in the northern part of the Intra-Sudetic Basin, are reported. This formation had been earlier assigned to the Upper Namurian and Lower Westphalian A on the basis of macrofloral and palynological data (Gothan and Gropp, 1933; Górecka, 1969) but these results needed checking against the modern international miospore zonation. We described many taxonomically diverse miospore assemblages from these rocks, which allowed to include them into two miospore zones, of Crassispora kosankei–Grumosisporites varioreticulatus (KV) and Raistrickia fulva–Reticulatisporites reticulatus (FR). These zones are correlated with part of the interval from the upper part of the Namurian A up to the Namurian C. The miospore zone Cirratriradites saturni–Triquitrites sinani (SS), identified by Górecka-Nowak (1987, 1995) from the Grzędy IG 1 borehole, extends the age range of the Biały Kamień Formation from Upper Namurian A to Lower Westphalian A. The documentation of these zones together with previous results of palynostratigraphic studies of the underlying Wałbrzych Formation corroborates the record of miospore zones of the Serpukhovian and Bashkirian in the Intra-Sudetic Carboniferous and suggests that there is no stratigraphic gap between the Wałbrzych and the Biały Kamień formations.