Korelacja utworów górnego dewonu i karbonu Pomorza Zachodniego w oparciu o badania miosporowe
Abstract
Correlations of Upper Devonian and Carboniferous deposits of Western Pomerania, based on miospore study
GEOLOGIC SETTING
The Upper Devonian and Carboniferous deposits of Western Pomerania occur in a narrow zone between Koszalin and Chojnice and in the vicinity of Kołobrzeg (Fig. 1). The Devonian and Carboniferous sediments are not folded and dip gently. The underlying Ordovician and Silurian rocks are strongly folded. Towards the north-east from the report area the Carboniferous sediments are missing; further to NE also the Devonian rocks are not present under the Zechstein, due to errosion. Toward the south-east, south-west and north-west 'the rocks older than Permian have not been reached in boreholes. The report area is strongly block faulted.
SPORE ZONES
1. Perotrilites Ordinarius zone (Or) is distinguished in (Upper?) Franian and probably Lower Famennian deposits. It is characterised by the presence of Perotrilites Ordinarius Turnau, Hystricosporites spp. end by abundance of acritairchs Gorgonisphaeridium plerispinosum Wicander and Micrhystridium stellatum Deflandre.
2. Grandispora cornuta (Co) zone (the assemblage 5, Turnau, 1975) was distinguished in the Upper Famennian deposits. It is characterised by the first appearance of Grandispora cornuta Higgs, Auroraspora macro Sullivan and Auroraspora multiplex Turnau.
3. Rugospora versabilis zone (Ve) (the assemblage 4, Turnau, 1975) is distinguished in uppermost Famenian deposits. The first appearing species are Spelaeotriletes lepidophytus (Kedo) Streel, Rugospora versabilis (Kedo) Streel and Grandispora conspicua (Playford) Playford.
4. Grandispora lupata zone (Lu), distinguished in the Tournaisian Tnla deposits, is characterized by the first appearance of Grandispora lupata Turnau and Spelaeotriletes lepidophytus (Kedo) Streel var. tener Kedo.
5. Tumulispora rarituberculata zone (Ra), distinguished in the Tournaisian Tnla and Tnlb deposits, is characterized by the first appearance of Tumulispora rarituberculata (Luber) Potonié, Knoxisporites literatus (Waltz) Playford, Corbulispora subalveolaris (Luber) Sullivan, and Raistrickia variabilis Dolby and Neves. In the uppermost part of the zone the presence of Verrucosisporites nitidus (Naumova) Playford was noted. The species occurring for the last time are, among others, Spelaeotriletes lepidophytus (Kedo) Streel and Rugospora versabilis (Kedo) Streel.
6. Convolutispora major zone (Ma), distinguished in the Tournaisian Tnlb?, Tn2, Tn3 deposits, is. characterized by the first appearance of Convolutispora major (Kedo) Turnau, Tumulispora dentata (Hughes and Playford) Turnau, Umbonatisporites distinctus Clayton, Pustulatisporites gibberosus (Haquebard) Playford and Raistrickia corynoges Sullivan. The last occurring species are: Hymenozonotriletes explanatus Kedo, type II (Turnau, 1978) and Archaeotriletes incrassatus Kedo.
7. The Prolycospora claytonii zone (Cl), distinguished in deposits of probably uppermost Tournaisian and Lower Visean age, is characterized by the first appearance of Prolycospora claytonii Turnau, Apiculiretusispora multiseta (Luber) Butterworth and Spinner, Anaplanisporites cf. delicatus Neves and Ioannides, Dictyotriletes margodentatus Turnau and Dictyotriletes membranireticulatus Bertelsen. Three subzones of the Cl zone are distinguishable. The lower subzone is marked by the last appearance of Tumulispora. The middle subzone is characterized by the first apperance of Auroraspora cf. solisortus Hoffmeister, Staplin and Malloy and Auroraspora panda Turnau. The last appearing species is Convolutispora major (Kedo) Turnau. The upper subzone is marked by the first appearance of Rugospora minuta Neves and Ioannides.
8. Lycospora pusilla (Pu) zone is of probably Lower to Middle Visean age (spore indications). It is characterized by the first regular occurrence of Lycospora pusilla (Ibrahim) Somers and the first appearance of Lophotriletes tribulosus Sullivan and Waltzispora planiangulata Sullivan. Crassispora trychera Neves and Ioannides and Apiculiretusispora multiseta (Luber) Butterworth and Spinner occur in this zone for the last time.
9. Schultzospora campyloptera zone (Ca) of probably upper-middle and lower-upper Visean age (spore indications) is characterized by the first appearance of Schulzospora spp. Anaplanisporites distinctus Neves and Ioannides occurs in the zone for the last time.
10. Dictyotriletes pactilis zone (Pa) of probably Upper Visean age is characterized by the first appearance of Dictyotriletes pactilis Sullivan and Marshall, Perotriletes tessellatus (Staplin) Neville, Chaetosphaerites pollenisimilis (Horst) Butterworth and Williams, Cingulizonates bialatus (Waltz) Smith and Butterworth, Murospora margodentata Beju and Potoniespores delicatus Playford.
11. Vestispora pseudoreticulata zone (Pse) of probably Westphalian B age (spore indications) is characterized by the presence of Vestispora pseudoreticulata Spode, Florinites junior Potonié and Kremp, Crassispora kosankei (Potonié and Kremp) Bharadwaj and Laevigatosporites vulgaris (Ibrahim) Alpern and Doubinger.
SPORE ZONES AND FAIJNISTIC AGE INDICATIONS
The age of the Upper Devonian and Tournaisian sediments implied by spores is in accord with that indicated by other fossil groups present. On the other hand, the Namurian and Westphalian age was ascribed to some strata based on pelecypods and ostracods; the spore evidence indicates the Lower Visean age of these sediments.
GEOLOGICAL IMPLICATIONS OF SPORE STUDY
The succession of spore assemblages found in the Upper Devonian nad Lower Carboniferous deposits is continuous, except for a minor non sequence between the zones Ra and Ma (the Tournaisian Tnlb). This suggests that in the Koszalin-Chojnice area the sedimentation of these deposits was, with one possible exception, uninterrupted. In a few borehole sections there occur distinct discontinuities between the spore zones. These may be due to faulting, as they occur haphazardly and involve different stratigraphic units in neighbouring boreholes. No Namurian spore assemblages were found by the author. The contact of the Westphalian and Visean deposits in the section Sarbinowo-1 may be a sedimentary one.
GEOLOGIC SETTING
The Upper Devonian and Carboniferous deposits of Western Pomerania occur in a narrow zone between Koszalin and Chojnice and in the vicinity of Kołobrzeg (Fig. 1). The Devonian and Carboniferous sediments are not folded and dip gently. The underlying Ordovician and Silurian rocks are strongly folded. Towards the north-east from the report area the Carboniferous sediments are missing; further to NE also the Devonian rocks are not present under the Zechstein, due to errosion. Toward the south-east, south-west and north-west 'the rocks older than Permian have not been reached in boreholes. The report area is strongly block faulted.
SPORE ZONES
1. Perotrilites Ordinarius zone (Or) is distinguished in (Upper?) Franian and probably Lower Famennian deposits. It is characterised by the presence of Perotrilites Ordinarius Turnau, Hystricosporites spp. end by abundance of acritairchs Gorgonisphaeridium plerispinosum Wicander and Micrhystridium stellatum Deflandre.
2. Grandispora cornuta (Co) zone (the assemblage 5, Turnau, 1975) was distinguished in the Upper Famennian deposits. It is characterised by the first appearance of Grandispora cornuta Higgs, Auroraspora macro Sullivan and Auroraspora multiplex Turnau.
3. Rugospora versabilis zone (Ve) (the assemblage 4, Turnau, 1975) is distinguished in uppermost Famenian deposits. The first appearing species are Spelaeotriletes lepidophytus (Kedo) Streel, Rugospora versabilis (Kedo) Streel and Grandispora conspicua (Playford) Playford.
4. Grandispora lupata zone (Lu), distinguished in the Tournaisian Tnla deposits, is characterized by the first appearance of Grandispora lupata Turnau and Spelaeotriletes lepidophytus (Kedo) Streel var. tener Kedo.
5. Tumulispora rarituberculata zone (Ra), distinguished in the Tournaisian Tnla and Tnlb deposits, is characterized by the first appearance of Tumulispora rarituberculata (Luber) Potonié, Knoxisporites literatus (Waltz) Playford, Corbulispora subalveolaris (Luber) Sullivan, and Raistrickia variabilis Dolby and Neves. In the uppermost part of the zone the presence of Verrucosisporites nitidus (Naumova) Playford was noted. The species occurring for the last time are, among others, Spelaeotriletes lepidophytus (Kedo) Streel and Rugospora versabilis (Kedo) Streel.
6. Convolutispora major zone (Ma), distinguished in the Tournaisian Tnlb?, Tn2, Tn3 deposits, is. characterized by the first appearance of Convolutispora major (Kedo) Turnau, Tumulispora dentata (Hughes and Playford) Turnau, Umbonatisporites distinctus Clayton, Pustulatisporites gibberosus (Haquebard) Playford and Raistrickia corynoges Sullivan. The last occurring species are: Hymenozonotriletes explanatus Kedo, type II (Turnau, 1978) and Archaeotriletes incrassatus Kedo.
7. The Prolycospora claytonii zone (Cl), distinguished in deposits of probably uppermost Tournaisian and Lower Visean age, is characterized by the first appearance of Prolycospora claytonii Turnau, Apiculiretusispora multiseta (Luber) Butterworth and Spinner, Anaplanisporites cf. delicatus Neves and Ioannides, Dictyotriletes margodentatus Turnau and Dictyotriletes membranireticulatus Bertelsen. Three subzones of the Cl zone are distinguishable. The lower subzone is marked by the last appearance of Tumulispora. The middle subzone is characterized by the first apperance of Auroraspora cf. solisortus Hoffmeister, Staplin and Malloy and Auroraspora panda Turnau. The last appearing species is Convolutispora major (Kedo) Turnau. The upper subzone is marked by the first appearance of Rugospora minuta Neves and Ioannides.
8. Lycospora pusilla (Pu) zone is of probably Lower to Middle Visean age (spore indications). It is characterized by the first regular occurrence of Lycospora pusilla (Ibrahim) Somers and the first appearance of Lophotriletes tribulosus Sullivan and Waltzispora planiangulata Sullivan. Crassispora trychera Neves and Ioannides and Apiculiretusispora multiseta (Luber) Butterworth and Spinner occur in this zone for the last time.
9. Schultzospora campyloptera zone (Ca) of probably upper-middle and lower-upper Visean age (spore indications) is characterized by the first appearance of Schulzospora spp. Anaplanisporites distinctus Neves and Ioannides occurs in the zone for the last time.
10. Dictyotriletes pactilis zone (Pa) of probably Upper Visean age is characterized by the first appearance of Dictyotriletes pactilis Sullivan and Marshall, Perotriletes tessellatus (Staplin) Neville, Chaetosphaerites pollenisimilis (Horst) Butterworth and Williams, Cingulizonates bialatus (Waltz) Smith and Butterworth, Murospora margodentata Beju and Potoniespores delicatus Playford.
11. Vestispora pseudoreticulata zone (Pse) of probably Westphalian B age (spore indications) is characterized by the presence of Vestispora pseudoreticulata Spode, Florinites junior Potonié and Kremp, Crassispora kosankei (Potonié and Kremp) Bharadwaj and Laevigatosporites vulgaris (Ibrahim) Alpern and Doubinger.
SPORE ZONES AND FAIJNISTIC AGE INDICATIONS
The age of the Upper Devonian and Tournaisian sediments implied by spores is in accord with that indicated by other fossil groups present. On the other hand, the Namurian and Westphalian age was ascribed to some strata based on pelecypods and ostracods; the spore evidence indicates the Lower Visean age of these sediments.
GEOLOGICAL IMPLICATIONS OF SPORE STUDY
The succession of spore assemblages found in the Upper Devonian nad Lower Carboniferous deposits is continuous, except for a minor non sequence between the zones Ra and Ma (the Tournaisian Tnlb). This suggests that in the Koszalin-Chojnice area the sedimentation of these deposits was, with one possible exception, uninterrupted. In a few borehole sections there occur distinct discontinuities between the spore zones. These may be due to faulting, as they occur haphazardly and involve different stratigraphic units in neighbouring boreholes. No Namurian spore assemblages were found by the author. The contact of the Westphalian and Visean deposits in the section Sarbinowo-1 may be a sedimentary one.