Christopher J. CLEAL
Department of Biodiversity & Systematic Biology, National Museum Wales, Cathays Park, Cardiff CF10 3NP, UK. E-mail: chris.cleal@museumwales.ac.uk

A revised macrofloral biostratigraphy for the Stephanian Ottweiler Group of the Saar- Lorraine Coalfield places most of the succession in the upper Stephanian B Substage (Alethopteris zeilleri Zone). Only the Breitenbach Formation at the top of the Group indicates a position in the middle Stephanian C Substage (Sphenophyllum angustifolium Zone). These revised correlations now make the tonstein date for the Wahlschied Seam, one of the few reliable radiometric dates for the Stephanian Stage, compatible with the recently proposed Carboniferous time scales. It also explains the large time gap at the base of the Holz Conglomerate suggested by the radiometric dates. There is now little evidence that the palynological ST Zone extends lower than the Stephanian B Substage, and that there appears to be a gap in the palynological zonation between the lower Cantabrian and top of the Barruelian Substages.

Key words: Stephanian, macrofloras, biostratigraphy, correlations

Christopher J. CLEAL
Department of Biodiversity & Systematic Biology, National Museum Wales, Cathays Park, Cardiff CF10 3NP, UK.
E-mail: chris.cleal@museumwales.ac.uk

The southern part of the Pennines Basin (Warwickshire, South Staffordshire and Wyre Forest coalfields) has a condensed succession of middle Langsettian to upper Asturian or lower Cantabrian strata. The Langsettian-Duckmantian part of the succession is in a grey coal-bearing facies, in which many coal seams have become vertically accreted, and in which macrofloras of the Laveineopteris loshii Subzone, Lonchopteris rugosa Zone and Neuropteris semireticulata Subzone can be recognised. Species composition and Total Species Richness diversity curves compare well with those from the Central Pennines Basin to the north, suggesting that they represent an essentially unified area of vegetation. Red beds of the Etruria Formation appear in the lower Bolsovian Substage (stratigraphically lower in the marginal southernmost part of the basin). The Etruria Formation macrofloras are not abundant, but where they do occur are not significantly less species-rich than in the contemporaneous grey coal-bearing sequence in the Central Pennines. The Etruria Formation macrofloras belong to the N. semireticulata Subzone, and there is no evidence of the overlying Laveineopters rarinervis Subzone that would indicate a late Bolsovian age. The grey, mainly arenaceous Halesowen Formation unconformably overlies the Etruria Formation, and yields low- diversity macrofloras that probably indicate the late Asturian Dicksonites plueckenetii Subzone. The succeeding red-beds of the Salop Formation yield even lower diversity macrofloras, but there is some evidence that they may belong to the Cantabrian O. cantabrica Zone. A comparison of these new data with the evidence from the Central Pennines helps confirm the robustness of Total Species Richness as a proxy for environmental change in Late Carboniferous palaeotropical coal-bearing sequences.

Key words: Carboniferous, palaeobotany, biostratigraphy, diversity-analysis

Ed. A. JARZEMBOWSKI
Maidstone Museum & Bentlif Art Gallery, St Faith's St, Maidstone, Kent ME14 1LH, UK. E-mail: edjarzembowski@maidstone.gov.uk

The earliest insect from Romania is described and named Phyloblatta resitensis sp. nov. based on the discovery of a unique tegmen from the lower Stephanian of the old Secu colliery tip, Resita Basin, southwest Romania. It is a cockroachoid (blattodean) and the first Carboniferous insect to be recorded from the border area of east and southeast Europe; hopefully, it represents the start of a new entomofauna. The taxonomic challenge of interpreting cockroachoid wing venation is briefly discussed.

Key words: Insecta, Blattodea, Phyloblatta new species, Carboniferous, Romania

Zbyněk ŠIMŮNEK
Czech Geological Survey, Klárov 3, 118 21 Praha 1, Czech Republic

The macrofloras of the Nýřany Member (late Asturian - early Cantabrian age) were studied at five localities and two boreholes in the Plzeň Basin (Western Bohemia). The floras were mostly dominated by Cordaites, and seven species were recognised based mainly on cuticular evidence. Cordaites dobranensis Šimůnek was the most common species and occurred in most of the Asturian-age localities. In addition, an outcrop near Heřmanova Huď yielded C. blazkovicensis Šimůnek, C. wilkischensis Šimůnek and C. pilsensis Šimůnek; and borehole Krašovice Kš 1 yielded C. krasovicensis Šimůnek and C. touskovensis Šimůnek. Cordaites radcicensis nov. sp. was only found in the Cantabrian part of the succession, at the Radčice locality, and shows characters suggesting adaptation to somewhat drier conditions, namely thick cutinisation and proximally oriented projection of the anticlinal cell walls. The most diversified assemblage with 29 species was found at the Dobřany locality, but most other localities yielded only 12 to 18 species. The species-spectrum of individual localities varied according to type of locality, sedimentology and method of collecting. In most localities, cordai- taleans made up 40 to 67% of the macroflora, the only notable exception being the Krimich II mine at Tlučná that yielded only 5% cordaitaleans. The next important plant group was the sphenopsids, which usually comprised about 30% of the macrofloras, with the exception of Heřmanova Huď locality where there were only 3% sphenopsids. The proportion of fern remains varied between localities from 8 to 35%. Lycopsids were usually very rare, except at the Heřmanova Huď locality where 30% of the flora consisted of allochthonous lycopsid fragments. Pteridosperms were very rare and never exceeded 10% of the macroflora. The Westphalian rain forest was not monotonous, but was diversified into several floral assemblages. My work supports the conclusion of previous workers in the area (Šetlík, 1980), that the five most common species in the Nýřany Member of the Plzeň Basin are Pecopteris polypodioides (Presl in Sternberg) Němejc, Sphenophyllum emarginatum (Brongniart) Brongniart, Pecopteris unita, Dicksonites plukenetii and Annularia stellata (Schlotheim) Wood.

Key words: Carboniferous, cordaitaleans, plant assemblages, cuticular analysis, Plzeň Basin

Dieter UHL¹ & Sunia LAUSBERG^2
1Laboratory of Palaeobotany and Palynology, Department of Palaeoecology, Utrecht University, Budapestlaan 4, 3584 CD Utrecht, The Netherlands. Present address: Villenstraße 13, 67433 Neustadt an der Weinstraße, Germany. E-mail: dieter.uhl@gmx.de
²Elisabethenstr. 34, D-7017 Stuttgart, Germany. E-mail: sunia.lausberg@web.de

For the first time, a quantitative analysis of the land-plant diversity during deposition of the Rotliegend (latest Pennsylvanian-Early Permian; Gzhelian - Sakmarian) of the Saar-Nahe basin (SW-Germany) and the Zechstein (Late Permian; Wuchiapingian) of the German Zechstein basin is given. A study of six taphofloras indicates that regionally not only the overall species richness declined, but also the diversity as represented by individual taphofloras. This decline occurred after the deposition of the Upper Rotliegend (Asselian-Sakmarian), leading to an extremely low species richness during the deposition of the Zechstein. Besides taphonomic differences between the indi- vidual localities considered here, possible reasons for the observed lower diversity include most probably a climatic deterioration/aridisation due to tectonic northwards movement of Pangaea. As compared to the Late Pennsylvanian and the Early Permian, this climatic deterioration together with a contemporaneous decrease in topographic relief due to erosion and collapse of the Variscan Orogen, may also be the main reason for a decrease in habitat diversity and finally the decrease in land-plant diversity. However, based on the data presented here it is difficult to judge whether the observed regional diversity decline at individual localities can be generalized for the entire Euramerican floral province. Nevertheless, it can be concluded from other sources, that there are large gaps in the palaeobotanical record of this region, which may lead to underestimation of the "true" land plant diversity during this period within the Euramerican floral province.

Key words: land-plant diversity, Euramerica, Germany, Pennsylvanian, Permian

Monika Agnieszka KUSIAK¹ & Nonna BAKUN-CZUBAROW^2
1Institute of Geological Sciences, Polish Academy of Sciences, Kraków Research Centre, ul. Senacka 1, 31-002 Kraków, Poland.
E-mail: ndkusiak@cyf‑kr.edu.pl
²Institute of Geological Sciences, Polish Academy of Sciences, ul. Twarda 51/55, 00-818 Warszawa, Poland.
E-mail: nbakun@twarda.pan.pl

Mineral chemistry and homogeneity, as well as crystal structure and unit cell parameters of detrital monazites isolated from sandstones of the Upper Silesia Coal Basin were studied using electron microprobe analysis (EPMA) and X-ray diffractometry (XRD). Analyzed monazite grains are chemically almost homogenous, only in a very few cases, parts of the grain are enriched in thorium and depleted in yttrium content. Typical feature of monazite from the Poruba Beds is relatively high content of Y (up to 4 wt. % Y2O3), what could point to higher temperature of crystallization. Monazite from the Kwaczała Arkose are, on average, richer in huttonite and slightly poorer in cheralite end-members than monazite from the Poruba Beds. Monazite from Kwaczała Arkose reveals the following unit cell parameters: a = 6.794(1) Å, b = 7.008(2) Å, c = 6.479(2) Å, b = 103.82(2)°, whereas for the Poruba Beds monazite these parameters, excluding b-value, are slightly higher: a = 6.804(3) Å, b = 7.002(5) Å, c = 6.488(4) Å, b = 103.85(3)°.

Key words: Upper Silesia Coal Basin, monazite, REE distribution patterns, XRD patterns, unit cell parameters, provenance indicator

Artur KĘDZIOR
¹Institute of Geological Sciences, Polish Academy of Sciences, Kraków Research Centre, ul. Senacka 1, 31-002 Kraków, Poland.
E-mail: ndkedzio@cyf‑kr.edu.pl

The Zabrze Beds (Namurian B) constitute a part of the flexural Variscan foredeep Upper Silesia Coal Basin (USCB) infill. On the Main Anticline area this unit starts the continental stage of the basin development. The Zabrze Beds were deposited on an extensive alluvial plain probably constructed by meandering river systems. The fluvial sediments were accumulated both within channels and on overbank areas. The thick (<5 m) sandstone bodies are considered as the channel fills and usually form extensive sheets whose width/thickness ratio exceeds 15. The thinner sandstone bodies, fine-grained sediments and phytogenic material were deposited on the overbank areas. The thickness of the Zabrze Beds on the Main Anticline area decreases eastward from ~250 m down to 3 m over a distance of 35 km. The thickness and number of the sandstone bodies diminish eastward with the thickness of the whole unit. The thickest bodies occur in the western part of the studied area, attaining 60 m, whereas in the eastern part they rarely exceed 30 m. As a rule, the thick sandstone bodies are laterally extensive approaching up to 10 km. Subordinately appear isolated bodies that are usually thinner. In those areas where the coarse-grained sediments are in the minority the inter- connectedness ratio is relatively low. The deposition of the thick sandstone bodies is related to stabilization of the river banks with accompanied balanced aggradations of the overbank areas, or is result of superposition of several generations of channel fills. The coal seams are numerous in the Zabrze Beds despite the small thickness of this unit. The growth of successive generations with extended eastward areas reflects increasing positive accommodation space created mainly by flexural bending of the basin substratum. The thirteen coal seams that have been identified within the Zabrze Beds, occur in different classes of thickness. Except thick (<3 m) and very thick (up to 24 m) seams, the laterally extensive and continuous coal seams are present thin (>0.3 m) and often lenticular in shape. The zones where the coal seam increase in thickness have been observed and they were the result of coalescence or the superposition of successively younger generation peat bogs. The characteristic feature of the succession of coal seams is the eastward increase of their lateral extend. The va- rious types of coal seam splitting have been observed. These phenomena were caused by lateral migration of the channel belts and growth of the crevasse splays, or by action of synsedimentary faults.

Key words: depositional architecture, Zabrze Beds, Namurian B, Upper Silesia Coal Basin, Poland.