Conodont, Miospore and Ostracod Zones Compared
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Annales Societatis Geologorum Poloniae (2000), vol. 70: 193-217. LOWER CARBONIFEROUS (MISSISSIPPIAN) STRATIGRAPHY OF NORTHWESTERN POLAND: CONODONT, MIOSPORE AND OSTRACOD ZONES COMPARED Hanna MATYJA1, Elżbieta TURNAU2 & Barbara ŻBIKOWSKA1 1 Polish Geological Institute, Rakowiecka 4, 00-975 Warszawa, Poland ~ Institute o f Geological Sciences, Polish Academy o f Sciences, Kraków Research Center, Kraków, Senacka I, 31-002 Kraków, Poland Matyja, H., Turnau, E. & Żbikowska, В., 2000. Lower Carboniferous (Mississippian) stratigraphy of northwestern Poland: conodont, miospore and ostracod zones compared. Annales Societatis Geologorum Poloniae, 70:193-217. Abstract: 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/sub zones and the ostracod assemblages/subassemblages are correlated with the Tournaisian sandbergi, Lower crenu- lata, 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. Abstrakt: Przedstawiono szczegółową stratygrafię turneju i wizenu Pomorza Zachodniego w oparciu o kono- donty, miospory i małżoraczki. Materia! do badań biostratygraficznych pochodził z 25 otworów wiertniczych. Zespoły miospor z badanych utworów zaliczono do dziewięciu wcześniej wyróżnionych jednostek biostratygra ficznych (zon i podzon). Dla turneju wyróżniono trzy kolejne zespoły i dwa podzespoły małżoraczków bento- nicznych. Zony/podzony miosporowe i zespoły/podzespoły małżoraczkowe skorelowano z turnejskimi zonami konodontowymi sandbergi, dolna crenulata, isosticha-górna crenulata i typicus. Obecność luki stratygraficznej na granicy dewon/karbon udokumentowano na podstawie konodontów i miospor. Granica turnej/wizen została ustalona jedynie w przybliżeniu, na podstawie pierwszego pojawienia się gatunku miosporowego Lycospora pusilla Somers. Key words: Tournaisian, Visean, biostratigraphy, conodonts, miospores, ostracods, western Pomerania. Manuscript received 27 April 2000, accepted 27 October 2000 INTRODUCTION Lower Carboniferous strata have been recorded in a even on folded lower Palaeozoic rocks (e.g., the Brda 2 number of wells drilled in the coastal part of western Pom borehole). This is due to a local tectonic and erosional epi erania and in the Koszalin-Chojnice area (Fig. 1). These sode, which took place at the end of the Devonian and dur strata were also encountered, but not pierced through, in ing the Tournaisian. The Tournaisian strata are, in most several wells located southwest of the latter area (Żeli cases, discordantly overlain by Permian sediments but in chowski, 1983; Żelichowski & Łoszewska, 1987). several sections near Sarbinowo, Karsina and Gozd, it is the In the study area, the lowermost Tournaisian is devel lower Visean which underlies the Permian rocks. Younger oped as the Sąpolno Calcareous Shale Formation, the base strata have been penetrated only in the Sarbinowo 1 section of which is Famennian in age (Matyja, 1993). It is likely that where the middle and upper Visean deposits rest uncon sedimentation was continuous across the Devonian-Car formably on the Ordovician (Bednarczyk, 1974), and are boniferous boundary, although a distinct stratigraphic gap discordantly overlain by the Westphalian. has been noted in some sections (Matyja & Stempień-Sałek, So far, the uppermost Visean and Namurian deposits 1994). In a few sections, however, different units of the have not been recorded in western Pomerania. The top of Tournaisian rest unconformably either on the lower Famen the Lower Carboniferous strata is probably of erosional nian (especially in the sections located in the Gozd area), or character and the documented gap spans the topmost 194 H. MATYJA ET AL. 15°00' 16°00' 17°00' 18°00‘ S arbinow o G rzybow o Gprzy§ł5w9^ 54°00'- Tournaisian and Visean CHOJNICI Upper Ordovician O Devonian and Silurian Middle Teisseyre-Tornquist Devonian tectonic line 25 Km Fig. 1. Location of discussed boreholes against the geological map of pre-Permian deposits in western Pomerania. Geology after Ma tyja, 1993, Lipiec & Matyja, 1998, modified. Insert - position of study area Visean, Namurian and lower part of Westphalian. logical logs as well as some old palynological slides have Toumaisian and Visean deposits in the Kołobrzeg- been reexamined. The here presented interpretation uses the Chojnice area show a great lithological variability. Incom upgraded miospore zonal scheme (see Subsection Zonal plete coring coupled with insufficient biostratigraphical schemes) and the results of recent miospore studies in Po data have been the main obstacles in reconstructing tire pat land and elsewhere. tern of development of the Devonian-Carboniferous suc Because our faunal and palynological samples are de cession. The first attempt to present the arrangement of the rived from the same boreholes, we were able to calibrate the Carboniferous lithological bodies and their general deposi- conodont, ostracod and miospore zonation schemes used. In tional environments, was that by Dadlez (1978). Żelichow this respect, we also discuss some macrofaunal data pub ski (1983, 1995; in Żelichowski & Łoszewska, 1987) re lished by Korejwo (1993). Our integrated biostratigraphic vised Dadlez’s lithostraphical division and subdivided database permitted to correlate the lithostratigraphic units Lower Carboniferous strata into several informal units and to date their boundaries. called complexes. For prospecting purposes more detailed The studies have been earned out in the Institute of division into units called “series” has been introduced by Geological Sciences of the Polish Academy of Sciences, Lech (1986). Recently, Lipiec (in Lipiec & Matyja, 1998) and in the Department of Regional and Petroleum Geology modified the division of Żelichowski. of the Polish Geological Institute. Early biostratigraphic investigations of the Carbonifer ous deposits in the studied area centered on macro- and mi crofauna (Błaszyk & Natusiewicz, 1973; Korejwo, 1976, LITHOSTRATIGRAPHY 1979; Matyja, 1976), and spores (Krawczyńska-Grochol- ska, 1975; Tumau, 1975, 1978, 1979; Górecka & Parka, The lithostratigraphic division used in the present paper 1980). A generalized summary of the biostratigraphic divi is that by Lipiec (in Lipiec and Matyja, 1998). Inferred spa sion based both on published and unpublished data, was tial relationships between the lithostratigraphic units are presented by Żelichowski & Łoszewska (1987). Some opin shown in Fig. 2. These relationships reflect a general regres ions on age assignements expressed in the earliest papers, sive tendency from an open shelf during the Famennian- were later revised (Matyja & Turnau, 1989; Clayton & Tur- middle Tournaisian (Sqpolno Calcareous Shale Formation), nau, 1990; Avkhimovitch et a!., 1993; Matyja, 1993; Ma through very shallow marine in the late Tournaisian (Ku- tyja & Stempień-Sałek, 1994), and the miospore zonal rowo Oolite Formation and Grzybowo Shale Member) to scheme proposed by Tumau (1978, 1979) was partly rede terrestrial environment during the latest Toumaisian (Drze- fined by Avkhimovitch & Tumau (1994) and upgraded by wiany Sandstone Formation). The Gozd Arkose Formation Stempień-Sałek (in Matyja & Stempień-Sałek, 1994). reflects the Tournaisian volcanic activity episodes. The details of the conodont and ostracod stratigraphy discussed in this paper are new. On the other hand, the mio Sqpolno Calcareous Shale Formation spore part involves only the sample material interpreted ear The uppermost Devonian-lowermost Carboniferous lier by Tumau (1975, 1978, 1979), and Avkhimovitch & Scipolno Calcareous Shale Formation overlies the Devonian Tumau (1994). Recently, all previously completed palyno- Krojanty and Klanino formations throughout the investi LOWER CARBONIFEROUS STRATIGRAPHY 195 gated area (see fig. 8 in Matyja, 1993). It is a succession of open marine carbonate and clayey deposits. The lower, Fa- Drzewiany Sandstone Formation mennian part of the formation consists of two lithofacies: (1) fossiliferous marly limestones in the shallower part of the basin (northern part of the area), and (2) fossiliferous Grzybowo Shale --------------^ marls with thin intercalations of organodetrital limestones Member Kurowo Oolite Formation in the deeper part of the basin (southern part of the area) (see Matyja, 1993; Matyja & Stempieri-Salek, 1994). Gozd ArKose Formation The younger, Toumaisian part of the formation consists Trzebiechowo mainly of black, fine-laminated clayey deposits in which Marl M Э. S^polno Calcareous Shale Formation faunal remains are rare. (upper part) The thickness of the formation (excluding the Trze- biechowo marl Member) varies from more than 300 m in the Wierzchowo-Kurowo area to only about 30 m in the Kar- Fig. 2. Generalized lithostratigraphic chart of Lower Carbonif erous deposits of Koiobrzeg-Chojnice area of western Pomerania lino region in the northern part of the area. (after Lipiec in Lipiec & Matyja, 1998, modified) Trzebiechowo