of the Netherlands are known (8). Halite ooids (halolites: 9) and mirabilite ooids (Dr Jose Pueyo Mur - oral in-formation 1985) were noted in recent sedimentary en-vironments.
The discussed gypsum ooids have been formed prob-ably nearby the shore in such places where the wave base exerted its influence on the bottom sediments and brine attained saturation allowing the gypsum to precipitate. The ooids were accumulated as the beach ridges similarily to the hali te ooids from the coast. of the Dead . Sea (9) or as subaqueous dunes and shoals (see 7 p. 109). The beach ridges and the shoals were washed away by storm waving and the oolitic sediments were transported and deposited in an offshore area.
REFERENCES
1. Ciara n fi N„ Da z z ar o L. et al. - I depositi del Miocene superiore al confine molisano-abruzzese. Boll. Soc. Geol. It. 1980 vol. 99.
2. Ciara n fi N„ Da z z ar o L. et al. - Preliminary description of some Messinian evaporitic facies along Abruzzi-Molise boundary. Mem. della Soc. Geol. It. 1978 vol. 16.
3. Kutek J. - Kimeryd i najwyższy oksford połud niowo-zachodniego obrzeżenia mezozoicznego Gór Świę tokrzyskich. Cz. Il. Paleogeografia. Acta Geol. Pol. 1969 nr 2.
4. Osm ó 1 ski T. - Perpektywy strontonośności 9a-denianu północnej strefy brzeżnej zapadliska przed-karpackiego na tle występowania strontu w Polsce. Arch. IG 1978.
5. Richter D.K. - Calcareous ooids: a synopsis. [In:] Coated Grains. Ed. T. Peryt. 1983.
6. S c h r e i b e r B.C. - Environments of subaqueous gypsum deposition. Marine Evaporites. SEPM Short Course Oklahoma City 1978 no. 4.
7. Schreiber B.C„ Hs ii K.J. - Evaporites. [In:] Developments in Petroleum Geology - 2. Ed. G.D. Hobson. 1980.
8. V o ort hu y se n van J.H. - Anhydrite formation irt the saline facies of the Miinder Mergel (Upper Malm). Geol. Mijnbouw 1951 vol. 13 no. 8.
9 We i 1 er Y., S as s E„ Z a k I. - Halite oolites and ripples in the Dead Sea, Israel. Sedimentology 1974 vol. 21 no. 4.
S T R E S Z C Z E N I.E
W środkowomioceńskich (badeńskich) osadach gip-sowych południowych stoków Gór Świętokrzyskich, w okolicach Staszowa, znaleziono gipsowe ooidy. Występu jący w cienkiej warstwie oolitowy osad jest interpretowany jako redeponowany przez sztormowe falowania z wałów brzegowych lub przybrzeżnych mielizn w strefę bardziej oddaloną od brzegu.
ANDRZEJ WITKOWSKI, WOLFGANG E. KRUMBEIN Uniwersytet Gdański, Universitat Oldenburg
SUBFOSSILIZED MICROORGANISMS FRO
M
THE BIOGENIC LAMINATED DEPOSITS
OF THE SHORE ZONE O
F
THE HEL PENINSULA
Until quite recently much more attention was paid to the algal mats and stromatolites from carbonate and mixed (carbonate and gypsum in generally siliciclastic deposits) environments than to siliciclastic environments. These investigations embeded both sedimentological and geomicrobiological aspects of stromatolites and microbial mats (e.g. 7, 16, 11, 8, 2, 14). Only since quite recently more attention has been given to the algal mats and stro-matolites from siliciclastic environments (1, 3, 12, 5, 6).
In constrast to the mats from subtropical carbonate environments, carbonates mineralisation does not occur in the humid climate-belt microbial mats. Generally the processes of calcification occur neither in microbial mats in temperate regions nor in those from tropical siliciclastic environments (1, 6, 7, 12). This is the main reason why it was thought that these microbial deposits could not be fossilized. It is a widespread belief that microorganisms developing on the quartz-sandy deposits have a rather small chance to be preserved, unless they have been rapidly buried, and anaerobie conditions have prevailed in the decay environment (15).
Geredes, Krumbein and Reineck (5, 6) investigated modern deposits from the tidal environment, the N orth Sea, which are created by microorganisms and in order to describe them they proposed the term "biogenie laminate su bfacies".
210
UKD 561.26:551.351.051 :552.581(438-17) All of the above quoted papers present the results of investigations carried out in hypersaline or marine en-vironment, whereas there are not materials devoted to brackish-water environment. On the other hand it is known that in terrestial environments, like peat bogs, microorganisms are mainly represented by fungi and heterotrophic bacteria (9, 4).
Sedimentological and microbiological mvestigations of biogenie laminated deposits (organie matter intercalated with quartz-sand) at the shore zone of the Inner Puck Bay have been carried out.
THE STUDY AREA
The Puck Bay is the Western part of the Gdańsk Bay and is separated from the open Baltic Sea by the Hel Peninsula. The waters of the Puck Bay with the salinity around 7 to 8°/00 represent a brackish-water environ-ment (mixomesohaline). Among the hydrodynamical fac-tors responsible for sediment transport in the Puck Bay, currents created by the water level changes are the most important ones. These changes caused by meteorological conditions appear irregularly but they can rise the water level by up to 1.0 m (average 30 cm). They are caused by heavy eastern or western winds blowing constantly for some period of time (12). At the extremely low water
levels, extensive areas of the bottom - even at the dis-tance of few hundreds meters from the shore line - are exposed.
The microbial mats at the coastal zone of the Puck Bay are composed of diverse cyanobacteria, chemoorgano-trophic bacteria, chemoautotropic bacteria (genus Be-giattoa), photosynthetic-anaerobic purple sulphur bacteria, diatoms and green algae. All of microorganisms which were found in biogenie laminated deposits have also been observed in the Puck Bay (10).
The biogenie laminated deposits (locally designated as coastal peat) occur along the coast Óf the Hel Peninsula. They form a kind of microcliff of approx. 0,5 m height. Near the shore line they are often destroyed by the waves at high water storm levels.
METHODS
Samples of the deposits with high content of organie matter were taken into sterile test tubes and immediately transferred to the laboratory. Then they were poured with medium for cyanobacteria after Allen and incubated in room temperature at light. After one month of incuba-tion, when the growth of phototrophic microorganisms was observed, BG11 medium (agar plates) and Fl medium (in flasks) were used to obtain unialgal and unicyano-bacterial cultures. Field samples were also observed directly after sampling under the light microscope.
RESULTS
An examination of the deposits at the shore zone of the Hel Peninsula revealed densely packed organie (peaty) layers of subrecent microbial mats intercalated with quartz-sandy deposits.
The organie layers are from severa! millimeters up to 1.5 cm thick. They are irregular in shape, the upper and !ower surfaces are undulating. An interna! bipartition is visible. In the !ower one (about 20 cm in thickness), the quartz-sandy deposits prevail. Three layers of peaty micro-bial mats are embedded in sands with bi- to multi-modal grain size distribution and a significant admixture of pebbles. The upper part (about 15 cm thick) is composed of peaty microbial mats alternating with medium sized quartz-sand.
Microscopic examinations enabled us to find in the biogenie laminated deposits the presence of a differentiated set of microalgae and bacteria. In the organie layers of the !ower part of the deposits Chlorophyceae prevailed from the genera: Ankistrodesmus and Scenedesmus and unicellular forms from the order Chlorococcales (the most common). Less frequent were Bacillariophyceae (genera: Navicula, Diploneis and Coscinodiscus)and Cyano-bacteria (genera: Lyngbya, Phormidium and coccoid forms). The set of microorganisms from the upper part is much more differentiated. In some layers the Cyano-bacteria prevailed but in others Chlorophyceae. There were established the unicellular and the filamentous forms. The filamentous forms were represented by the Cyanobacteria ( Oscillatoria sp„ Lyngbya sp„ and
Phor-midium sp.) and Chlorophyceae (Ulotrix sp.). These forms were incubated only from some layers but the empty sheaths of filamentous forms were present in layers from !ower and upper parts.
Among the coccoid Cyanobacteria, Synechococcus · sp„
Microcystis aeruginosa, Merismopedia punctata, M. glauca
and M. tenuissima prevailed. Less frequently Gloeocapsa
minima and Aphanothece castagnei occurred. Like in the lower part the unicellular Chlorophyceae from the order Chlorococcales and the representatives of genera
Anki-strodesmus and Scenedesmus were present.
Diatoms occur in all layers. The following forms were identified to the genus level: Navicula, Nitzschia,
Achnan-tes, Diploneis and Coscinodiscus.
Besides, the phototrophic microorganisms, chemoor-ganotrophic bacteria (rod shaped and coccoid) and fungi equally frequently occurred. The examination of samples suspended in sterile water revealed the presence of micro-bial detritus. Sheaths of filamentous and coccoid forms were found as well as fragments of colonies.
CONCLUSIONS
The laminated microbial mat deposits comprise some typical mat forming cyanobacteria with some eukaryotic algae admixed. The coccoid and filamentous Cyano-bacteria: Synechococcus, M icrocystis, M erismopedia,
Apha-nothece, Gloeocapsa, Oscillatoria, Lyngbya and Phormidium as well as Chlorophyceae (also coccoid and filamentous),
Chlorococcales, Ankistrodesmus, Scenedesmus and Ulotrix were recorded quite frequently in the peaty materiał. The diatoms Diploneis, Achnantes, Navicula, Nitzschia and Coscinodiscus were recorded less frequently.
The environmental factors (salinity and temperature) are much less extreme than in the tropical microbial de-posits. Eukaryotes therefore are very important consti-tuents of this community. Besides, viable microorganisms, many empty sheaths of both filamentous and coccoid forms were found to be preserved in large amounts. Be-cause of the method used it is too difficult to estimate quantitative relationships between the particular groups of microbes and viability of cell fractions.
The sedimentological and microbiological analysis enabled us to find similarities between the laminated de-posits from the Puck Bay and processes described by Stolz and Margulis from Laguna Figueroa, Mexico (15). It is likely that the sand transported by the currents during increases of the water level in the Puck Bay have rapidly buried the layers of microbial debris. After that burying the reductive conditions could be created by the activity of sulphatereducing bacteria.
In conclusion it is possible to state that these deposits seem to manifest that the preservation of distinguishable microorganisms ( especially Cyanobacteria) in a quartz--sandy environment is possible but depends on conditions of preservation. Acidity of peat like deposits in a brackish--water environment m~y favour the preservation even more, than in siliciclastic Atlantic or North Sea intertidal
stromatolitic systems.
ACKNOWLEDGEMENTS
The authors wish to express their thanks to Dr. J. Nie-radko from the Department of Microbiology, University of Gdańsk for his help in the study of microbiological methods, and to Dr. T.M. Peryt for his critical reading of the manuscript.
REFERENCES
1. Camer o n B„ Camer o n D„ Jo n es J.R. -Modern algal mats in intertidal and supratidal quartz sands, Northeastern Massachusetts, USA. [In:] Curran
H.A. (ed.) Biogenie Structures: Their Use in
preting Depositional Environments. SEPM Spec. Publ. 1985 no. 35.
2. Cohen Y„ Ca sten ho 1 z R.W„ Ha 1 v er-s o n H.O. (eder-s) - Microbial Mater-s: Stromatoliteer-s. Alan R. Liss Inc. New York 1984.
3. Davis R.A. - Algal stromatolites composed of quartz sandstone. J. Sedim. Petrol. 1968 vol. 38. 4. Dick i n son C.H. - Microorganisms in peatlands. [In:] Gore A.J.P. (ed.) Mires: Swamp, Bog, Fen and Moor, Ecosystems of the World 4A. Elsevier, Am-sterdam Oxford New York 1983.
5. Gere des G„ Kr umb ei n W.E„ Re i nec k H-E. - Verberaitung und aktuogeologische Bedeutung mariner mikrobieller Matten im Gezeitenbereich der N ordsee. Facies. 1985a vol. 12.
6. Gere des G„ Kr umb ei n W.E„ Re i nec k H-E. - The depositional record of sandy versicolored tidal flats (Mellum island, Southern North Sea).
J. Sedim. Petrol. 1985b vol. 55.
7. Gu n at i 1 a ka A. - Some aspects of the biology and sedimentology of laminated algal mats from Man-nar Lagoon, NW Ceylon. Sedim. Geol. 1975 vol. 14. 8. Kr umb ei n W.E. - Stromatolites - the challenge of a term in space and time. Precambrian Res. 1983 vol. 20.
9. Kii ster E. - Microbiology of peai. [In:] W.E. Krumbein (ed.) Environmental Biogeochemistry and Geomicrobiology. Ann Arbor Sci. Publ. Ann Arbor, Michigan 1979.
10. P 1 iński M. - Glony Zatoki Gdańskiej. Uniwer-sytet Gdański 1979.
11. P o n c e t J. - Contrasted occurrence of Eodevonian stromatolites, Armorican Massif, France. [In:] Monty Cl.L.V. (ed.) Phanerozoic Stromatolites. Springer-Verlag Berlin 1981.
12. Schwarz H.U„ Ei n se 1 e G„ Herm D. -Quartz-sandy, grazing contoured stromatolites from coastal embayment of Mauritania, West Africa. Sedi-mentology 1975 vol. 22.
13. Słomianko P. et al. - Zatoka Pucka -
pers-pektywy rozwoju gospodarczego rejonu. Stud. i Mater. Oceanolog. 1974 z. 4.
14. St o 1 z J.F. - Fine structure of the stratified micro-bial community of Laguna Figueroa, Baja California, Mexico: II. Transmission electron microscopy as a diagenetic tool in studying microbial communities in situ. [In:] Cohen Y„ Castenholz R.W„ Halvorson H.O. (eds) Microbial Mats: Stromatolites. Alan R. Liss Inc. New York 1984.
15. St o 1 z J.F„ Mar gu I is L. - The stratified com-munity at Laguna Figueroa, Baja California, Mexico: a proposed model for Prephanerozoic laminated micro-bial communities preserved in cherts. Origins of Life 1984 vol. 14.
16. W a 1 ter M.R. (ed.) - Stromatolites. Developments in Sedimentology 20. Elsevier Amsterdam 1976.
STRESZCZENIE
Laminowane osady biogeniczne (naprzemianległe la-miny piasków kwarcowych i materii organicznej) ze strefy brzegowej Płw. Helskiego badano przy użyciu metod sedymentologicznych i mikrobiologicznych. Próbki osadów pobierano do sterylnych probówek i po przewiezieniu do laboratorium zalewano płynną pożywką Allena a następnie oświetlone inkubowano w temperaturze pokojowej.
W wyniku przeprowadzonych badań mikroskopowych w laminach organicznych obok mikroorganizmów typo-wych dla środowiska mat glonowych (sinice) stwierdzono
również występowanie organizmów eukariotycznych (zie-lenice, okrzemki). Wśród sinic obserwowano zarówno formy jednokomórkowe: Microcystis, Merismopedia,
G!oeo-capsa, Aphanothece jak i nitkowate: Oscillatorża, Lyngbya,
Phormidium. Podobnie wśród zielenic obserwowano formy
jednokomórkowe: Ankistrodesmus, Scenedesmus,
Chloro-coccales i nitkowate - Ulotrix. Natomiast okrzemki
re-prezentowane były przez Navicula, Nitzschia, Diploneis,
Achnantes i Coscinodiscus.
Przeprowadzone badania pozwalają na stwierdzenie,
że laminowane osady biogeniczne świadczą o tym, iż fosyli-zacja mikroorganizmów w środowisku piasków kwarco-wych jest możliwa, ale zależy od warunków w jakich proces ten przebiega.
TERESA POPEK Instytut Geologiczny
PRZEJAWY WULKANIZMU W GÓRNYM WIZENIE NA OBSZARZE LUBELSKIM
Na przełomie dewonu i karbonu, na obszarze lubleskim,
utworzyły się skały wylewne, piroklastyczne i hipabisalne.
Skały piroklastyczne napotkano zarówno wśród utworów efuzywnych, jak i ekstruzywnych. Efuzywne utwory piro-klastyczne reprezentowane są przez tufolawy przechodzące
miejscami w utwory sprawiające wrażenie peperytu lub tufu peperinowego (3). Występują one z reguły w dolnym odcinku profilu utworów wizenu górnego. Tufolawy są skałami mieszanymi, wykazującymi zarówno cechy potoku lawowego, jak też tufu spieczonego. Nagromadziły się one
głównie w środowisku wodnym, prawdopodobnie morskim
(płytkiej strefy nerytycznej), ewentualnie limniczym. W
środowiskach tych odbywała się depozycja materiału w górnym wizenie (1). Wprawdzie pierwotny charakter
che-212
UKD 552.313:551.735.1(438.14) miczny tych skał został zatarty przez ich późniejszą
ality-zację, to jednak uważa się je na ogół za produkty magm o małej lepkości (2), a więc zasadowych.
Wśród karbońskich utworów ekstruzywnych na
ob-szarze lubelskim stwierdzono dotychczas jedynie kwaśne skały wulkanogeniczne reprezentowane przez tufy, tufity oraz piaskowce tufogeniczne występujące w górnym wize-nie. Stanowią one przedmiot niniejszego artykułu. Przed-stawione poniżej obserwacje poczyniono w trakcie badań płytek cienkich pochodzących ze skał nawierconych w SE,
częściowo centralnej i NW części LZW (ryc. 1, tab.).
Posłużono się przy tym klasyfikacją skał piroklastycznych
zalecaną przez podkomisję IUGS (4).
