Hostname: page-component-77c89778f8-5wvtr Total loading time: 0 Render date: 2024-07-17T05:37:04.070Z Has data issue: false hasContentIssue false

Burial Diagenetic Processes and Clay Mineral Formation in the Molasse Zone of Upper Austria

Published online by Cambridge University Press:  28 February 2024

Susanne Gier*
Affiliation:
Institute of Petrology, University of Vienna, Geozentrum, Althanstraße 14, 1090 Vienna, Austria

Abstract

Cores of pelitic sediments (Eocene-Miocene) of the drillings Puchkirchen 1 and Geretsberg 1 (Molasse Basin, Upper Austria) have been studied to determine the mineralogical and chemical changes taking place during burial diagenesis. Mineralogical and chemical investigations of the bulk samples show that the deepest samples of the profiles are derived from a different source area. In particular, there is an increase in kaolinite and chlorite with depth and a decrease in quartz related to the initial sedimentology and provenance.

Investigations of the <2 µm and <0.2 µm fractions of the profiles Puchkirchen 1 and Geretsberg 1 reveal the diagenetic overprint of the mineral constituents: The gradual illitization of mixed-layer illite-smectite, also reflected in an increase of K2O and Al2O3, is displayed most prominently in the <0.2 µm fraction. The source for the Al and K is the dissolution of K-feldspar (<2 µm fraction), as indicated in many previous studies.

The I-S mixed-layer phases are randomly interlayered to a depth of 1600 m; from there on a regular interstratified I-S phase appears in coexistence with the randomly interlayered I-S mixed layer. The randomly oriented phase is still present in major amounts to depths of 2500 m, presumably as a result of the low geothermal gradient (2.9 °C/100 m) in the Molasse Basin.

The calculation of the structural formula of the end members illite and smectite from this series of I-S mixed-layer phases gave the following results: Smectite: $${K_{0.14}}{X^ + }_{0.44}\left( {A{l_{1.10}}M{g_{0.46}}F{e_{0.36}}T{i_{0.01}}} \right)S{i_{4.03}}{O_{10}}{\left( {OH} \right)_2}$$

Illite: $${K_{0.44}}{X^ + }_{0.19}\left( {A{l_{1.26}}M{g_{0.42}}F{e_{0.38}}T{i_{0.01}}} \right)\left( {S{i_{3.52}}A{l_{0.48}}} \right){O_{10}}{\left( {OH} \right)_2}$$

The end-member interlayer charge for the smectite component (+0.58) is higher than reported for typical smectites (+0.32 to +0.47). It is suggested that the I-S phases of the Molasse Basin are probably intergrowths of 3 layer-silicate members: illite, low-charged smectite and high-charged smectite. The determined smectite end-member composition represents, therefore, an average for a variable 2-component smectite system. The charge-differences of the 2 smectites would likely reflect the differences in source material, which in turn would have led to the formation of different early, highly smectitic I-S phases in the sedimentary basin.

Type
Research Article
Copyright
Copyright © 1998, The Clay Minerals Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

APD 3. 5B., 1992 PC-APD 3. 5B, Philips PW 1877 Automated powder diffraction .Google Scholar
Association Nationale de la Recherche Technique., 1989 Geostandards newsletter 13 (Special Issue) 23.CrossRefGoogle Scholar
Awwiller, D.N., 1993 Mite smectite formation and potassium mass transfer during burial diagenesis of mudrocks: A study from the Texas Gulf Coast Paleocene-Eocene J Sed Pet 63 501512.Google Scholar
Bruce, C.H., 1984 Smectite dehydration—Its relation to structural development and hydrocarbon accumulation in northern Gulf of Mexico Basin AAPG Bull 68 673683.Google Scholar
Burst, J.F., 1969 Diagenesis of Gulf Coast clayey sediments and its possible relation to petroleum migration AAPG Bull 53 7393.Google Scholar
Busenberg, E. and Clemency, C.V., 1973 Determination of the cation exchange capacity of clays and soils using an ammonia electrode Clays Clay Miner 21 213217 10.1346/CCMN.1973.0210403.CrossRefGoogle Scholar
Deer, W.A., Howie, R.A. and Zussman, J.. 1962. Rock-forming minerals—Sheet silicates, vol. 3. Longmans.Google Scholar
Eberl, D.D., 1993 Three zones for illite formation during burial diagenesis and metamorphism Clays Clay Miner 41 2637 10.1346/CCMN.1993.0410103.CrossRefGoogle Scholar
Eberl, D.D. Środoń, J. Mingchou, L. Nadeau, P.H. and Northrop, H.R., 1987 Sericite from the Silverton caldera, Colorado: Correlation among structure, composition, origin and particle thickness Am Mineral 72 914934.Google Scholar
Eberl, D.D. Środoń, J. and Northrup, H.R., 1986 Potassium fixation in smectite by wetting and drying Geochemical processes at mineral surfaces. Am Chem Soc Symposium Series 323 296326 10.1021/bk-1987-0323.ch014.Google Scholar
Glover, E.D., 1961 Method of solution of calcareous materials using the complexing agent, EDTA J Sed Pet 31 622626 10.1306/74D70C18-2B21-11D7-8648000102C1865D.CrossRefGoogle Scholar
Horton, R.B. Johns, W.D. and Kurzweil, H., 1985 Hüte diagenesis in the Vienna Basin, Austria TMPM 34 239260.Google Scholar
Hower, J. Eslinger, E.V. Hower, M.E. and Perry, E.A., 1976 Mechanism of burial metamorphism of argillaceous sediment: 1. Mineralogical and chemical evidence Geol Soc Am Bull 87 725737 10.1130/0016-7606(1976)87<725:MOBMOA>2.0.CO;2.2.0.CO;2>CrossRefGoogle Scholar
Jasmund, K. and Lagaly, G., 1993 Tonminerale und Tone Darmstadt Steinkopff 10.1007/978-3-642-72488-6.CrossRefGoogle Scholar
Johns, W.D. and Kurzweil, H., 1979 Quantitative estimation of il-lite-smectite mixed-phases formed during burial diagenesis TMPM 26 203215.Google Scholar
Köhler, E. and Wewer, R., 1980 Gewinnung reiner Tonmineralkonzentrate für die mineralogische Analyse Keramische Zeitschrift 32 Nr. 5 250252.Google Scholar
Köster, H.M., 1979 Die chemische Silikatanalyse Berlin Springer-Verlag 10.1007/978-3-642-67275-0.CrossRefGoogle Scholar
Köster, H.M., Van Olphen, H. and Veniale, F., 1981 The crystal structure of 2:1 layer silicates Developments in sed-imentology. Proc Int Clay Conf; 1981 Amsterdam Elsevier 4171.Google Scholar
Kunz, B., 1978 Temperaturmessungen in Erdölbohrungen der Molassezone Oberösterreichs Mitt ÖsterrGeol Ges 68 5158.Google Scholar
Kurzweil, H., 1973 Sedimentpetrologische Untersuchungen an den jungtertiären Tonmergelserien der Molassezone Oberösterreichs TMPM 20 169215.Google Scholar
Kurzweil, H. and Johns, W.D., 1981 Diagenesis of tertiary marl-stones in the Vienna Basin TMPM 29 103125.Google Scholar
Lagaly, G. and Weiss, A., 1976 The layer charge of smectitic layer silicates Mexico City Proc Int Clay Conf 157172.Google Scholar
Lynch, F.L., 1997 Frio shale mineralogy and the stoichiometry of the smectite to illite reaction: The most important reaction in clastic sedimentary diagenesis Clays Clay Miner 45 618631 10.1346/CCMN.1997.0450502.CrossRefGoogle Scholar
Malzer, O. Rögl, F. Seifert, P. Wagner, L. Wessely, G. Brix, F., Brix, F. and Schultz, O., 1993 Die Molassezone und deren Untergrund Erdöl und Erdgas in Österreich Wien NHM Wien 281323.Google Scholar
Marshall, C.E., 1949 The structural interpretation of chemical analyses of the clay minerals The colloid chemistry of the silicate minerals New York Academic Pr.Google Scholar
Moore, D.M. and Reynolds, R.C. Jr., 1989 X-ray diffraction and the identification and analysis of clay minerals New York Oxford Univ Press.Google Scholar
Perry, E.A. and Hower, J., 1972 Late-stage dehydration in deeply buried pelitic sediments AAPG Bull 56 20132021.Google Scholar
Powers, M.C., 1967 Fluid-release mechanisms in compacting marine mudrocks and their importance in oil exploration AAPG Bull 51 12401254.Google Scholar
Reynolds, R.C. Jr, 1985 NEWMOD©, a computer program for the calculation of one-dimensional diffraction patterns of mixed-layered clays Hanover, NH R. C. Reynolds, Jr.: 8 Brook Drive.Google Scholar
Reynolds, R.C. Jr., 1989 Principles and techniques of quantitative analysis of clay minerals by X-ray powder diffraction Quantitative mineral analysis of clays, CMS Workshop Lectures 1 436.Google Scholar
Schultz, L.G., 1964 Quantitative interpretation of mineralogical composition from X-ray and chemical data for Pierre shale Washington. US Geol Survey. Prof Paper 391-C 10.3133/pp391C.CrossRefGoogle Scholar
Stul, M.S. and Mortier, W.J., 1974 The heterogeneity of the charge density in montmorillonites Clays Clay Miner 22 391396 10.1346/CCMN.1974.0220505.CrossRefGoogle Scholar
Sucha, V. Kraus, I. Geithofferova, H. Petes, J. and Serekova, M., 1993 Smectite to illite conversion in bentonites and shales of the East Slovak Basin Clay Miner 28 243253 10.1180/claymin.1993.028.2.06.CrossRefGoogle Scholar
Sucha, V. and Siranova, V., 1991 Ammonium and potassium fixation in smectite by wetting and drying Clays Clay Miner 39 556559 10.1346/CCMN.1991.0390511.CrossRefGoogle Scholar
Tollmann, A., 1985 Die Molassezone. Geologie von Österreich. Band 2 Wien Verlag Franz Deuticke.Google Scholar
Yoder, H.S. and Eugster, H.P., 1955 Synthetic and natural musco-vites Geochim Cosmochim Acta 8 225280 10.1016/0016-7037(55)90001-6.CrossRefGoogle Scholar