Diagenesis of Tertiary marlstones in the Vienna Basin
Tóm tắt
To investigate the diagenetic changes of Tertiary pelitic sediments in the Vienna Basin a suite of drill core samples from the OeMV-bore-hole Aderklaa 78 has been studied using mineralogical and chemical methods. The sediments generally correspond to shales and cover a section from 780–2812 m depth. Their mineralogical composition is complex and variable and mainly due to the initial variation in detrital constituents at the time of sedimentation and the local sedimentary environments. Quartz, feldspars (sodic-plagioclase, K-feldspar), carbonates (calcite, dolomite, siderite), phyllosilicates (mica, chlorite, kaolinite, illite-smectite mixed-layers), and pyrite to a minor extent are the essential components of the shales. The analytical data of bulk samples and the less than 0.2 micron fractions point out that mechanical compaction of the sediments was accom inied by isochemical changes within the shale sequence. The diagenetic overprint of the mineral constituents is revealed by a decrease with depth of K-feldspar and an increase of quartz respectively, but especially by the gradual illitization of smectite via mixed-layer intermediates. Burial diagenesis in this Vienna Basin profile therefore can be expressed by the mineral reaction: K-feldspar+smectite→illite+quartz. A local reversal in all these trends in the basal Tertiary section can be explained by unusually high magnesium contents of the pore waters which inhibited illitization by promoting the stability of smectite relative to illite.
Tài liệu tham khảo
Burst, J. F., 1969: Diagenesis of Gulf Coast clayey sediments and its possible relation to petroleum migration. Amer. Assoc. Petrol. Geol. Bull.53, 73–93.
Dunoyer de Segonzac, G., 1965: Les argiles du Crétacé supérieur dans le bassin de Douala (Cameroun): Problèmes de diagenèse. Bull. Serv. Carte géol. Als. Lorr.17, fasc. 4, 287–310.
1970: The transformation of clay minerals during diagenesis and low-grade metamorphism: a review. Sedimentology15, 281–346.
Fuchs, W., 1980: Das inneralpine Tertiär. In: Der geologische Aufbau Österreichs (Geol. Bundesanst. Wien, ed.). Wien-New York: Springer.
Hower, J., Eslinger, E. V., Hower, M. E., Perry, E. A., 1976: Mechanism of burial metamorphism of argillaceous sediment. 1. Mineralogical and chemical evidence. Bull. Geol. Soc. Amer.87, 725–737.
Janoschek, R., 1951: Das inneralpine Wiener Becken. In: Geologie von Österreich, 2. Aufl. (Schaffer, F. X., ed.), Wien: Deuticke.
Janoschek, R., 1958: The Inner-Alpine Vienna Basin. An example of a small sedimentary area with rich oil accumulation. In: Habitat of oil. A symposium, Tulsa.
,Götzinger, K., 1969: Exploration for oil and gas in Austria. In: The exploration for petroleum in Europe and North Africa, Inst. Petroleum. Dorking: Adler.
Johns, W. D., Kurzweil, H., 1979. Quantitative estimation of illite-smectite mixed phases formed during burial diagenesis. Tschermaks Min. Pitr. Mitt.26, 203–215.
Kröll, A., 1980: Das Wiener Becken. In: Erdöl und Erdgas in Österreich (Bachmayer, F., ed.). Wien-Horn: Naturhist. Museum-Berger.
Norrish, K., Hutton, J. T., 1969: An accurate X-ray spectrographic method for the analysis of a wide range of geological samples. Geochim. Cosmochim. Acta,33, 431–453.
Schröckenfuchs, G., 1975 Hydrogeologie, Geochemie und Hydrodynamik der Formationswässer des Raumes Matzen-Schönkirchen Tief. Erdöl-Erdgas Z.91, 299–321.
Schultz, L. G., 1964: Quantitative interpretation of mineralogical composition from X-ray and chemical data for Pierre shale. U. S. Geol. Survey Prof. Paper 391-C, p. C1–C31.
Wieseneder, H., 1953: Zur Diagenese klastischer Sedimente im Wiener Becken. Tschermaks Min. Petr. Mitt.3, 142–153.
,Maurer, I., 1958: Ursachen der räumlichen und zeitlichen Änderung des Mineralbestandes der Sedimente des Wiener Beckens. Eclog. Geol. Helv.51, 1155–1172.