Biostratigraphy of the Famennian from the borehole Chojnice4 (Western Pomerania) The stratigraphic position of Upper Devonian sediments from column Chojnice 4 has been more closely determined on the basis of conodont and brachiopod fauna, referred to the conodont Palmatolepsis marginifera and Scaphignatus velifer Zones. In the ammonite division they correspond to the uppermost part of the Cheiloceras and Platyclymenia (do IIβ – do IIIβ) Zones. Łobanowski (1968) tentatively assigned them to the Upper Devonian (? Frasnian) deposits. The occurrence has been observed of the species Polygnathus semicostatus Branson and Mehl in the Palmatolepis marginifera Zone. One new cocodont form from the genus Polygnathus has been described.
Początek dewonskiej sedymentacji w polnocno-zachodniej Polsce: przeslanki palinologiczne
Palynomorph assemblages of low taxonomic diversity are recorded from the basal Devonian strata in three boreholes in western Pomerania and Kujawy. The palynoflora is assigned to a younger, autochtonous assemblage, and an older, redeposited one. The composition of the younger assemblage suggests lower to middle Eifelian. The older palynomorphs are derived from (1) Upper Ordovician or Lower Silurian, and (2) probably from Upper Silurian deposits.
Lithofacies and conodonts in Visean profile, Olkusz area, southern Poland The investigated WB-94 borehole profile (100 % core) is located at the north-eastern margin of the Upper Silesian·Coal Basin, in vicinity of Olkusz (Fig. 1). Predominant in the profile (Fig. 2) are dark marly spiculitic calcilutites with layered or lemses-shaped black cherts, comparable to the Wilson's (1975) standard microfacies 1 (PI. 1, Figs. 1-2;Pl. 2, Fig. 1; Pl. 3, Fig. 2). The autochthonous marly beds are intercalated with grey to pinkish homogeneous intrabiosparenites containing abundant abraded and redoposited skeletons of echinoderms, brachiopods, foraminifers (mostly endotyrids), bryozoans and various calcareous·algae (Pl. 1, Fig. 3;.Pl. 2, Fig. 2;·PI.·3, Fig. 1). This microfacies corresponds to SMP 4 and 5 (Wilson, 1975). Laminated fine calcarenites and calcilutites, with cherts in plaes, form the intermediate litological variety. The biostratigraphic study of 10 (including positive) conodont samples (see Table 1, and Fig. 2 for location in the profile) is based upon the Lower Carboniferous conodont zonation constructed by Austin (1974) with some modifications by Groessens (1974) and Groessens, Conil & Lees (1976). Stratigraphically important and/or taxonomically interesting formtaxa are illustrated on Plates 4-8 and described in the paleontological part. The occurrence of Gnathodus sp./aff Paragnatthodus commutatus (Branson & Mehl)/and Mestognathus sp. in the lowermost dated sample (215.3 m) indicates that it is not older than the upper part of the Visean Mestognathus beckmanni Zone. In turn, the sample from depth 187.7 m is not younger than the lowermost part of the Visean Gnathodus bilineatus bilineatus Zone as indicated by the stratigraphic ranges of Gnathodus delicatus Branson & Mehl and Gnathodus sp. indet. (Meischner 1970, Boogaert 1967,Higgins 1974, Matthews & Thomas 1974). The uppermost dated sample (depth 183.1 m) contains stratigraphically mixed conodont assemblage with the admixture of the typical Famenian and Tournaisian forms (Table 1). The admixture is most probably related to the redeposition of some contemporaneously eroded Upper Devonian to Lower Carboniferous conodont-bearing carbonates within the Lower Carboniferous shelf platform (cf. Bojkowski & Bukowy 1966, Jurkiewicz & Żakowa 1972). The·investigated lithofacie beIongs to the anaerobic marginal deeper shelf with intense redeposition from the intra-basinaI or coastal shoals inhabited by abundant benthic assemblages.
Stratygrafia dolnego karbonu (missisippian) Pomorza Zachodniego: porownanie zon konodontowych, miosporowych i malzoraczkowych
Detailed stratigraphy of the Tournaisian and Visean in western Pomerania has been established on conodonts, miospores and ostracods recovered from 25 boreholes. Miospore associations from the Tournaisian and Visean are assigned to nine biostratigraphic units (zones and subzones) erected earlier. Three successive benthic ostracod assemblages and two sub-assemblages are distinguished for the Tournaisian. The miospore zones/subzones and the ostracod assemblages/subassemblages are correlated with the Tournaisian sandbergi, Lower crenulata, isosticha-XJppex cremilata, and typicus conodont zones. Stratigraphic gap has been demonstrated at the Devonian/Carboniferous boundary, using the results of both conodont and miospore studies. The Tournaisian/ Visean boundary has been established approximately on the first appearance of the miospore species Lycospora pusilla Somers.
Przedstawiono szczegolową stratygrafie turneju i wizenu Pomorza Zachodniego w oparciu o konodonty, miospory i malzoraczki. Material do badan biostratygraficznych pochodzil z 25 otworow wiertniczych. Zespoly miospor z badanych utworow zaliczono do dziewieciu wcześniej wyroznionych jednostek biostratygraficznych (zon i podzon). Dla turneju wyrozniono trzy kolejne zespoly i dwa podzespoly malzoraczkow bentonicznych. Zony/podzony miosporowe i zespoly/podzespoly malzoraczkowe skorelowano z turnejskimi zonami konodontowymi sandbergi, dolna crenulata, isosticha-gorna crenulata i typicus. Obecnośc luki stratygraficznej na granicy dewon/karbon udokumentowano na podstawie konodontow i miospor. Granica turnej/wizen zostala ustalona jedynie w przyblizeniu, na podstawie pierwszego pojawienia sie gatunku miosporowego Lycospora pusilla Somers.
Abstract A multidisciplinary study of the Devonian–Carboniferous boundary interval in pelagic successions of the Holy Cross Mountains and Sudetes and the ramp successions in the Western Pomerania region (Poland) is presented herein. The analysis applies the results of new palaeontological and biostratigraphic studies based mainly on conodonts, ammonoids and palynomorphs, biostratigraphic results interpreted earlier by different authors that have been re-examined, and geochemical and mineralogical characteristics, as well as magnetic susceptibility measurements across the Devonian–Carboniferous boundary interval. The study is focused on the interval from the Famennian ultimus conodont Zone to the Tournaisian duplicata conodont Zone, and from the Famennian lepidophyta – explanatus (LE) miospore Zone to the Tournaisian verrucosus – incohatus (VI) miospore Zone, respectively. The paper highlights sections, which are the most representative for the Devonian–Carboniferous boundary in each region, illustrates and summarises current knowledge on the uppermost Famennian to lowermost Tournaisian in these regions, gives data and correlation of the important stratigraphic markers for each region, and briefly correlates them outside the region. The sedimentary successions and specific phenomena, together with microscale environmental perturbations, recognised close to the Devonian/Carboniferous boundary in Poland, display a pattern similar to that observed in many areas in Europe during the Hangenberg Event.
The results are here presented of the biostratigraphic and lithological investigations of the uppermost Devonian and Lower Carboniferous from the Chojnice region. They are based chiefly on a detailed analysis of brachiopod and conodont assemblages. The Upper Famennian (Fa2) with deposits equivalent to the Etroeungt beds of France and BeIgium (Tn1a), also the proper Touraisian (sensu Heerlen 1935) have been distinguished. The stratigraphic position of the Devonian/Carboniferous passage beds of Europe are discussed in the light of paleontological studies. Consideration is given to the sediments of this age in Poland. A description is given of the facial-paleogeographic development in the sedimentary basin of the Chojnice region at the Devonian/Carboniferous turn, two sedimentary zones being differentiated there. All the faunal remains here worked out have been figured, but descriptions are given only of forms whose generic or specific assignment is controversial. A survey of all the phenomena noted on the Devonian/Carboniferous passage beds, also the exceptionally great depth of the sediments – the age equivalents in the Chojnice area of the Etroeungt beds (Tn1a) – reasonably suggest that this area is of essential all-European importance for the clearing up of the problems of the Dewonian/Carboniferous passage beds and the boundary between these two systems.
The holothurian sclerites are here described for the first time from the Upper Devonian the world over and also for the first time from the Devonian of Poland. The sclerites found are assigned to the genus Eocaudina Martin. Several so far known species have been analyzed critically and three new ones, viz. Eocaudina gornensis sp. n., E. ovalis sp. n. and E. quinqueordinata sp. n. erected. The stratigraphic occurrences of particular species from the Upper Devonian are compared with the ·conodont zonation.
W trakcie dokladnych badan konodontowych reperowych profili pogranicza fran-famen (F-F) w Gorach Świetokrzyskich (Kowala) i rejonie Krakowa (Debnik) natrafiono na trudności w biostratygraficznym rozpoznaniu tej naturalnej granicy pieter, odpowiadającej zdarzeniu wielkiego wymierania, jak i dokumentowaniu jej geochemicznej specyfiki. Sukcesja zespolow konodontowych przez krytyczny poziom F-F wykazuje zaskakująco stopniowy charakter, manifestujący sie glownie we wspolwystepowaniu typowo franskich palmatolepidow i ancyrodellidow z diagnostycznym dla famenu, bardzo zmiennym gatunkiem Palmatolepis triangularis (obejmującym morfotyp praetriangularis). Profile pierwiastkow śladowych oraz izotopow wegla, tak weglanowego, jak i organicznego, wskazują na przewaznie „spokojny“, pozbawiony wazniejszych zdarzen interwal pogranicza F-F sensu stricto, choc byc moze odpowiadający najwyzszym poziomom produktywności. Najwieksze zmiany oceanograficzne mialy miejsce w pierwszej fazie sedymentacji gornego poziomu Kellwasser w dobie linguiformis, a wiec przed kryzysem konodontow. Dane te wzmacniają scenariusz rozciągnietego w czasie, zlozonego kryzysu biotycznego wskutek oddzialywania czynnikow ziemskich, ale nie globalnej katastrofy kosmicznej.
BIOSTRATIGRAPHICAL AND GEOCHEMICAL PROBLEMS WITH IDENTIFICATION OF THE FRASNIAN-FAMENNIAN BOUNDARY IN THE SOUTHERN POLAND
Summary
High-resolution conodont studies of reference Frasnian-Famennian (F-F) sections in the Holy Cross Mts (Kowala) and Cracow area (Debnik) revealed difficulties in the biostratigraphical recognition of this natural stage boundary corresponding to the major extinction event, as well as documentation of its supposed geochemical peculiarity. Surprisingly graded pattern of the conodont succession across the critical level is documented, manifested primarily in co-occurrence of typical Frasnian palmatolepids and ancyrodellids with the broadly variable diagnostic Famennian species Palmatolepis triangularis (encompassing praetriangularis morphotype). Carbon isotopic (both carbonate and organic) and trace element profiles of the F-F boundary sensu stricto point to generally quiet, uneventful aspect of the interval, but maybe marked by highest productivity levels. Most significant oceanographic changes are linked with onset of the transgressive-hypoxic Kellwasser Event, still within the latest Frasnian linguiformis Chron, i.e. well before the conodont
