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A strontium isotope and trace element geochemical study of dolomite-bearing bentonite deposits in Bavaria (Germany)

  • Mathias H. Köster (a1), Stefan Hölzl (a2) and H. Albert Gilg (a1)

Abstract

The Landshut bentonites that formed from Ca- and Mg-poor rhyolitic tuffs in a fluviatile-lacustrine depositional environment of the Miocene Upper Freshwater Molasse, southern Germany, contain abundant palustrine, pedogenic and groundwater carbonates. Geochemical analyses of dolomites, calcites and smectites from bentonites of various environments by X-ray diffraction, thermal ionization mass spectrometry, inductively coupled plasma-mass spectrometry, and handheld X-ray fluorescence yield new insights into the compositions of fluids and sources of imported components involved in carbonate formation and bentonitization, as well as the timing of bentonite formation. Evaporated, Sr-rich brackish surface water with a molar Mg/Ca ratio of 2–5, derived mostly from the weathering of detrital carbonates, was involved in dolomite and bentonite formation in palustrine and some pedogenic environments. However, Sr-poor groundwater with a molar Mg/Ca ratio of ∼ 1 and a stronger silicate weathering component caused bentonite and calcite formation in strictly pedogenic and groundwater settings. The 87Sr/86Sr and molar Mg/Ca in the smectite interlayers indicate later cation exchange with water having more radiogenic Sr sources and smaller molar Mg/Ca ratios. The Rb-Sr data indicate the common presence of detrital illitic phases in the <0.2 μm fractions of the bentonites. Cogenetic palustrine dolomite and a single smectite residue sample which lacks this detrital illitic phase provide an age constraint for bentonitization at 14.7 ± 4.1 Ma identical to primary ash deposition. Thus a rapid onset of bentonitization of accumulated ash and dolomite formation in evaporation-driven wetland environments is indicated for the genesis of the Landshut bentonites.

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Abdul-Aziz, H., Boumlhme, M., Rocholl, A., Zwing, A., Prieto, J., Wijbrans, J.R., Heissig, K. & Bachtadse, V. (2010) Integrated stratigraphy and 40Ar/39Archronology of the Early to Middle Miocene Upper Freshwater Molasse. International Journal of Earth Sciences, 97, 115134.
Anadón, P., Utrilla, R. & Vázquez, A. (2002) Mineralogy and Sr–Mg geochemistry of charophyte carbonates: a new tool for paleolimnological research. Earth and Planetary Science Letters, 197, 205214.
Arp, G. & Wiesheu, R. (1997) Ein kontinuierliches Profil von Algenbiohermen bis zu Seetonen des miozänen Rieskratersees: sequenzen, Mikrofazies und Dolomitisierung. Geologische Blätter für Nordost-Bayern, 47, 461486.
Banner, J.L. (1995) Application of the trace element and isotope geochemistry of strontium to studies of carbonate diagenesis. Sedimentology, 42, 805824.
Bau, M. & Möller, P. (1992) Rare earth element fractionation in metamorphogenic hydrothermal calcite, magnesite and siderite. Mineralogy and Petrology, 45, 231246.
Blum, J.D., Gazis, C.A., Jacobsen, A.D. & Chamberlain, C.P. (1998) Carbonate vs. silicateweathering in the Raikhot watershed within the High Himalayan crystalline series. Geology, 26, 411414.
Böhme, M., Bruch, A.A. & Selmeier, A. (2007) The reconstruction of Early and Middle Miocene climate and vegetation in southern Germany as determined from the fossil wood fauna. Palaeogeography, Palaeoclimatology, Palaeoecology, 253, 91114.
Budd, D.A. (1997) Cenozoic dolomites of carbonate islands: their attributes and origin. Earth-Science Reviews, 42, 147.
Bustillo, M.A., Arribas, M.E. & Bustillo, M. (2002) Dolomitization and silicification in low-energy lacustrine carbonates (Paleogene, Madrid Basin, Spain). Sedimentary Geology, 151, 107126.
Canadell, J., Jackson, R.B., Ehleringer, J.R., Mooney, H.A., Sala, O.E. & Schulze, E.-D. (1996) Maximum rooting depth of vegetation types at the global scale. Oecologia, 108, 583595.
Casado, A.I., Alonso-Zarza, A.M. & La Iglesia Á. (2014) Morphology and origin of dolomite in paleosols and lacustrine sequences. Examples from the Miocene of the Madrid Basin. Sedimentary Geology, 312, 5062.
Chaudhuri, S. & Brookins, D.G. (1979) The Rb-Sr systematics in acid-leached clay minerals. Chemical Geology, 24, 231242.
Clauer, N. (1979) Relationship between the isotopic composition of strontium in newly formed continental clay minerals and their source material. Chemical Geology, 27, 115124.
Clauer, N., Hoffert, M. & Karpoff, A.-M. (1982) The Rb-Sr isotope system as an index of origin and diagenetic evolution of southern Pacific red clays. Geochimica et Cosmochimica Acta, 46, 26592664.
Cleveland, G.B. (1960) Geology of the Otay bentonite deposits, San Diego County, California. California Division of Mines. Special Report, 64, 16 pp.
Clow, D.W., Mast, M.A., Bullen, T.D. & Turk, J.T. (1997) Strontium 87/strontium 86 as a tracer of mineral weathering reactions and calcium sources in an alpine/ subalpine watershed, Loch Vale, Colorado. Water Resources Research, 33, 13351351.
Decher, A., Bechtel, A., Echle, W., Friedrich, G. & Hoernes, S. (1996) Stable isotope geochemistry of bentonites from the island of Milos (Greece). Chemical Geology, 129, 101113.
Delgado, A. (1993) Estudio isotópico de los procesos diagenéticos e hidrotermales relacionados con la génesis de bentonitas (Cabo de Gata, Almería). Thesis doctoral. Universidad de Granada, España, 410 p.
Delgado, A. & Reyes, E. (1993) Isotopic study of the diagenetic and hydrothermal origins of the bentonite deposits at Los Escullos (Almería, Spain). Pp. 675678 in: Current Research in Geology Applied to Ore Deposits (P. Fenoll Hach- Ali, J. Torres-Ruiz & F. Gervilla, editors). University of Granada, Spain.
Dromgoole, E. & Walter, L. (1990) Iron and manganese incorporation into calcite: effects of growth kinetics, temperature and solution chemistry. Chemical Geology, 81, 311336.
Eberl, D.D., Środoń, J. & Northrop, H.R. (1986) Potassium fixation in smectite by wetting and drying. Pp. 296326 in: Geochemical Processes at Mineral Surfaces (Davis, J.A. & Hayes, K.F., editors). American Chemical Society Symposium Series, 323, American Chemical Society, Washington, D.C.
Eberl, D.D., Velde, B. & McCormick, T. (1993) Synthesis of illite-smectite from smectite at Earth surface temperatures and high pH. Clay Minerals, 28, 4960.
Egger, R., Eichinger, L., Rauert, W. & Stichler, W. (1983) Untersuchung zum Grundwasserhaushalt des Tiefenwassers der Oberen Süßwassermolasse durch Grundwasseraltersbestimmung. Informationsberichte Bayerisches Landesamt für Wasserwirtschaft, 8/83, 99145.
Eichinger, L., Lorenz, G. & Heidinger, M. (2007) Bohrung Uetlibergtunnel: interpretation der isotopenhydrologischen, hydrochemischen und gasphysikalischen Untersuchungsergebnisse. Nagra Arbeitsbericht, NAB 07–08, 159.
Folk, R.L. & Land, L.S. (1975) Mg/Ca ratio and salinity: two controls over crystallization of dolomite. American Association of Petroleum Geologists Bulletin, 59, 6068.
Freudenberger, W. & Schwerd, K. (1996) Erläuterungen zur Geologischen Karte von Bayern 1:500000. Bayerisches Geologisches Landesamt, Germany, 329 pp.
Frisch, W., Kuhlemann, J., Dunkl, I., & Brügel, A. (1998) Palinspastic reconstruction and topographic evolution of the Eastern Alps during late Tertiary tectonic extrusion. Tectonophysics, 297, 115.
Gaines, A.M. (1980) Dolomitization kinetics: recent experimental studies. SEPM Special Publication, 28, 8186.
Gao, X., Wang, P., Li, D., Peng, Q.,Wang, C. & Ma, H. (2012) Petrologic characteristics and genesis of dolostone from the Campanian of the SK-I Well Core in the Songliao Basin, China. Geoscience Frontiers, 3, 669680.
García del Cura, M.A., Calvo, J.P., Ordonez, S., Jones, B.F. & Canaveras, J.C. (2001) Petrographic and geochemical evidence for the formation of primary, bacterially induced lacustrine dolomite: La Roda ‘white earth’ (Pliocene, Central Spain). Sedimentology, 48, 897915.
Gasse, F., Fontes, J.C., Plaziat, J.C., Carbonel, P., Kaczmarska, I., de Deckker P., Soulié-Marsche I., Callot, Y. & Dupeuble, P.A. (1987) Biological remains, geochemistry and stable isotopes for the reconstruction of environmental and hydrological changes in the Holocene lakes from North Sahara. Palaeogeography, Palaeoclimatology, Palaeoecology, 60, 146.
Geske, A., Zorlu, J., Richter, D.K., Buhl, D., Niedermayr, A. & Immenhauser, A. (2012) Impact of diagenesis and low grade metamorphosis on isotope (δ26Mg, δ13C, δ18O and 87Sr/86Sr) and elemental (Ca, Mg, Mn, Fe and Sr) signatures of Triassic sabkha dolomites. Chemical Geology, 332–333, 4564.
Gilg, H.A. (2005) Eine geochemische Studie an Bentoniten und vulkanischen Gläsern des nordalpinen Molassebeckens (Deutschland, Schweiz). Pp. 1618 in: Berichte der Deutschen Ton- und Tonmineralgruppe e.V., Beiträge zur Jahrestagung Celle 10.-12. Oktober 2005 (R. Dohrmann, editor). Deutsche Ton- und Tonmineralgruppe, Köln, Germany.
Gilg, H.A., Weber, B., Kasbohm, J. & Frei, R. (2003) Isotope geochemistry and origin of illite-smectite and kaolinite from the Seilitz and Kemmlitz kaolin deposits, Saxony, Germany. Clay Minerals, 38, 95112.
Goldsmith, J.R. & Graf, D.L. (1958) Structural and compositional variations in some natural dolomites. The Journal of Geology, 66, 678693.
Govindaraju, K. (1989) Compilation of working values and sample description for 272 Geostandards. Geostandards and Geoanalytical Research, 13, 1113.
Graup, G., Horn, P., Köhler, H. & Müller-Sohnius, D. (1981) Source material for moldavites and bentonites. Naturwissenschaften, 68, 616617.
Grim, R.E. & Güven, N. (1978) Origin of bentonites. Pp. 7879 in: Bentonites: Geology, Mineralogy, Properties and Uses (Grim, R.E. & N. Güven, editors). Development in Sedimentology, 24. Elsevier, Amsterdam.
Hird, K. (1985) Petrography and geochemistry of some Carboniferous and Precambrian dolomites. Doctoral thesis. Durham University, UK, pp. 340343.
Horn, P., Müller-Sohnius, D., Köhler, H. & Graup, G. (1985) Rb-Sr systematics of rocks related to the Ries Crater, Germany. Earth and Planetary Science Letters, 75, 384392.
Horwitz, E.P., Chiarizia, R. & Dietz, M.L. (1992) A novel strontium-selective extraction chromatographic resin. Solvent Extraction and Ion Exchange, 10, 313336.
Hugget, J. & Cuadros, J. (2005) Low-temperature illitization of smectite in the Late Eocene and Early Oligocene of the Isle of Wight (Hampshire basin). U.K. American Mineralogist, 90, 11921202.
Imai, N., Terashima, S., Itoh, S. & Ando, A. (1995) Compilation of analytical data for minor and trace elements in seventeen GSJ geochemical reference samples, “igneous rock series”. Geostandards Newsletter, 19, 135213.
Jin, L., Williams, E.L., Szramek, K.J., Walter, L.M. & Hamilton, S.K. (2008) Silicate and carbonate mineral weathering in soil profiles developed on Pleistocene glacial drift (Michigan, USA): mass balances based on soil water geochemistry. Geochimica et Cosmochimica Acta, 72, 10271042.
Kainzmaier, B., Thom, P., Wrobel, M. & Pukowietz, C. (2007) Geowissenschaftliche Landesaufnahme in der Planungsregion 13 Landshut. Pp. 8188 in: Erläuterungen zur Hydrogeologischen Karte 1:100000 (Wagner, B., editor). Bayerischen Geologisches Landesamt, Augsburg, Germany.
Kallis, P., Bleich, K.E. & Stahr, K. (2000) Micromorphological and geochemical characterisation of Tertiary ‘freshwater carbonates’ locally preserved north of the edge of the Miocene Molasse Basin (SW Germany). Catena, 41, 1942.
Knechtel, M.M. & Patterson, S.H. (1956) Bentonite deposits in marine Cretaceous Formations, Hardin District, Montana and Wyoming. US Geological Survey Bulletin, 1023, 1116.
Knechtel, M.M. & Patterson, S.H. (1962) Bentonite deposits of the Northern Black Hills District, Wyoming, Montana and South Dakota. US Geological Survey Bulletin, 1082-M, 8931030.
Köhler, H., Frank, C., Königsberger, T. & Schön, B. (2008) Isotopische (Sr, Nd) Charakterisierung und Datierung Variskischer Granitoide der Moldanubischen Kruste Nordostbayerns. Geologica Bavarica, 110, 170203.
Köster, M.H. & Gilg, H.A. (2015) Pedogenic, palustrine and groundwater dolomite formation in non-marine bentonites (Bavaria, Germany). Clay Minerals, 50, 163183.
Kralik, M. (1983) Interpretation of K-Ar and Rb-Sr data from fine fractions of weakly metamorphosed shales and carbonate rocks at the base of the Northern Calcareous Alps (Salzburg, Austria). Tschermaks Mineralogische und Petrographische Mitteilungen, 32, 4967.
Kretz, R. (1982) A model for the distribution of trace elements between calcite and dolomite. Geochimica et Cosmochimica Acta, 46, 19791981.
Last, W.M. (1980) Sedimentology and postglacial history of Lake Manitoba. PhD thesis. University of Manitoba, Winnipeg, Canada, 687 pp.
Last, W.M. (1990) Lacustrine dolomite – an overview of modern, Holocene, and Pleistocene occurrences. Earth-Science Reviews, 27, 221263.
Laudelout, H., van Bladel R., Bolt, G.H. & Page, A.L. (1968) Thermodynamics of heterovalent cation exchange reaction in a montmorillonite clay. Transactions of the Faraday Society, 64, 14771488.
Lemcke, K. (1973) Zur nachpermischen Geschichte des nördlichen Alpenvorlandes. Geologica Bavarica, 69, 548.
Lemcke, K. (1988) Geologie von Bayern. Bd.1. Das Bayerische Alpenvorland vor der Eiszeit. Schweizerbart’sche Verlagsbuchhandlung, Stuttgart, Germany, 175 pp.
Lohmann, K.C. (1988) Geochemical patterns of meteoric diagenetic systems and their application to studies of paleokarst. Pp. 5880 in: Paleokarst (James, N.P. & P. W. Choquette, editors). Springer-Verlag, New York.
Lorens, R.B. (1981) Sr, Cd, Mn and Co distribution coefficients in calcite as a function of calcite precipitation rate. Geochimica et Cosmochimica Acta, 45, 553561.
Ludwig, K.R. (2008) User's Manual for Isoplot 3.70. A Geochronological Toolkit for Microsoft Excel. Berkeley Geochronology Center Special Publication, 4, 76 pp.
Lumsden, D.N. & Chimahusky, J.S. (1980) Relationship between dolomite nonstoichiometry and carbonate facies parameters. Pp. 123137 in: Concepts and Models of Dolomitization (Zenger, D.H., Dunham, J.B. & Ethington, R.L., editors). Special Publication No. 28, Society of Economic Palaeontologists and Mineralogists, Tulsa, Oklahoma, USA.
Maurer, H. & Buchner, E. (2007) Identification of fluvial architectural elements of meandering systems by paleosols (Upper Freshwater Molasse, North Alpine Foreland Basin, SW-Germany). Zeitschrift der Deutschen Gesellschaft für Geowissenschaften, 158, 271285.
McArthur, J.M., Howarth, R.J. & Bailey, T.R. (2001) Strontium isotope stratigraphy: LOWESS Version 3: best fit to the marine Sr-isotope curve for 0–509 Ma and accompanying look-up table for deriving numerical age. The Journal of Geology, 109, 155170.
Möller, P., Morteani, G. & Dulski, P. (1984) The origin of the calcites from the Pb–Zn veins in the Harz Mountains, Federal Republic of Germany. Chemical Geology, 45, 91112.
Moore, D.M. & Reynolds, R.C. (1997) X-Ray Diffraction and the Identification and Analysis of Clay Minerals. Oxford University Press, New York, 378 pp.
Müller, G., Irion, G. & Förstner, U. (1972) Formation and diagenesis of inorganic Ca–Mg carbonates in the lacustrine environment. Naturwissenschaften, 59, 158164.
Nance, W.B. & Taylor, S.R. (1976) Rare earth element patterns and crustal evolution, I, Australian post- Archean sedimentary rocks. Geochimica et Cosmochimica Acta, 40, 15391551.
Nelson, C.S. & Smith, A.M. (1996) Stable oxygen and carbon isotopes composition fields for skeletal and diagenetic components in New Zealand Cenozoic nontropical carbonate sediments and limestones: a synthesis and review. New Zealand Journal of Geology and Geophysics, 39, 93107.
Pin, C. & Basin, C. (1992) Evaluation of a strontiumspecific extraction chromatographic method for isotopic analysis in geological materials. Analytica Chimica Acta, 269, 249255.
Rimstidt, J.D., Balog, A. & Webb, J. (1998) Distribution of trace elements between carbonate minerals and aqueous solutions. Geochimica et Cosmochimica Acta, 62, 18511863.
Sánchez-Román, M., Romanek, C.S., Fernández-Remolar, D.C., Sánchez-Navas, A., McKenzie, J.A., Pibernat, R.A. & Vasconcelos, C. (2011) Aerobic biomineralization of Mg-rich carbonates: implications for natural environments. Chemical Geology, 281, 143150.
Sayles, F.L. & Mangelsdorf, P.C. Jr. (1979) Cation exchange characteristics of Amazon River suspended sediment and its reaction with seawater. Geochimica et Cosmochimica Acta, 43, 767779.
Schmid, W. (2002) Ablagerungsmilieu, Verwitterung und Paläoböden feinklastischer Sedimente der Oberen Süßwassermolasse Bayerns. Bayerische Akademie der Wissenschaften, Heft 172, Doctoral thesis. Ludwig-Maximilians-Universität, Germany, 247 pp.
Schroll, E. & Wieden, P. (1960) Eine rezente Bildung von Dolomit im Schlamm des Neusiedler Sees. Tschermaks Mineralogische und Petrographische Mitteilungen, 7, 286289.
Siebel, W., Reitter, E., Wenzel, T. & Blaha, U. (2005) Sr isotope systematics of K-feldspars in plutonic rocks revealed by the Rb–Sr microdrilling technique. Chemical Geology, 222, 183199.
Środoń, J. (1980) Precise identification of illite/smectite interstratifications by X-ray powder diffraction. Clays and Clay Minerals, 28, 401411.
Stanjek, H. & Marchel, C. (2008) Linking the redox cycles of Fe oxides and Fe-rich clay minerals: an example from a palaeosol of the Upper Freshwater Molasse. Clay Minerals, 43, 6982.
Tompa, É., Nyirodblac-Kósa, I.,Rostási, Á., Cserny, T. & Pósfai, M. (2014) Distribution and composition of Mg-calcite and dolomite in the water and sediments of Lake Balaton. Central European Geology, 57, 113136.
Tucker, M.E. & Wright, V.P. (1990) Carbonate Sedimentology. Blackwell Science, Oxford, UK, pp. 168172.
Tütken, T. & Vennemann, T.W. (2009) Stable isotope ecology of Miocene large mammals from Sandelzhausen, southern Germany. Paläontologische Zeitschrift, 83, 207226.
Tütken, T., Vennemann, T.W., Janz, H. & Heinzmann, E.P.J. (2006) Palaeoenvironment and palaeoclimate of the Middle Miocene lake in the Steinheim basin, SW Germany: a reconstruction from C, O, and Sr isotopes of fossil remains. Palaeogeography, Palaeoclimatology, Palaeoecology, 241, 457491.
Ulbig, A. (1994) Vergleichende Untersuchungen an Bentoniten, Tuffen und sandig-tonigen Einschaltungen in den Bentonitlagerstätten der Oberen Süßwassermolasse. Doctoral thesis. Technische Universität München, Germany, 245 pp.
Ulbig, A. (1999) Untersuchungen zur Entstehung der Bentonite in der bayerischen Oberen Süßwassermolasse. Neues Jahrbuch Geologisch- Paläontologische Abhandlungen, 214, 497508.
Unger, H.J. (1981) Bemerkungen zur stratigraphischen Stellung, der Lagerung und Genese der Bentonitlagerstätten in Niederbayern. Verhandlungen der Geologischen Bundesanstalt, Wien, 1981/2, 193203.
Unger, H.J. (1991) Geologische Karte von Bayern 1:50000 – Erläuterungen zum Blatt Nr. L 7538 Landshut. Bayerisches Geologisches Landesamt, München, Germany, 213 pp.
Unger, H.J. (1996) Östliche Vorlandmolasse und Braunkohlentertiär i. w. S. Pp. 168185 in: Geologische Karte von Bayern 1:500000 (Freudenbacher, W. & Schwerd, K., editors). Bayerisches Geologisches Landesamt, München, Germany.
Unger, H.J. (1999) Die tektonischen Strukturen der bayerischen Ostmolasse. Documenta Naturae, 125, 116.
Unger, H.J. & Niemeyer, A. (1985) Bentonitlagerstätten zwischen Mainburg und Landshut und ihre zeitliche Einstufung. Geologisches Jahrbuch, D71, 5993.
Unger, H.J., Fiest, W. & Niemeyer, A. (1990) Die Bentonite der ostbayerischen Molasse und ihre Beziehungen zu den Vulkaniten des Pannonischen Beckens. Geologisches Jahrbuch, D96, 5566.
Vahrenkamp, V.C. & Swart, P.K. (1990) New distribution coefficient for the incorporation of strontium into dolomite and its implications for the formation of ancient dolomites. Geology, 18, 387391.
van Lith Y., Warthmann, R., Vasconcelos, C. & McKenzie, J.A. (2003) Sulphate-reducing bacteria induce lowtemperature Ca-dolomite and high Mg-calcite formation. Geobiology, 1, 7179.
Voerkelius, S., Lorenz, G.D., Rummel, S., Quétel, C.R., Heiss, G., Baxter, M., Brach-Papa, C., Deters-Itzelsberger, P., Hoelzl, S., Hoogewerff, J., Ponzevera, E., Bocxstaele, M.V. & Ueckermann, H. (2010) Strontium isotopic signatures of natural mineral waters, the reference to a simple geological map and its potential for authentication of food. Food Chemistry, 118, 933940.
Vogt, K. (1980) Bentonite deposits in Lower Bavaria. Geologisches Jahrbuch, D39, 4768.
Vogt, K. & Köster, H.M. (1978) Zur Mineralogie, Kristallchemie und Geochemie einiger Montmorillonite aus Bentoniten. Clay Minerals, 13, 2543.
Waber, H.N., Heidinger, M., Lorenz, G. & Traber, D. (2014) Hydrochemie und Isotopenhydrogeologie von Tiefengrundwässern in der Nordschweiz und im angrenzenden Süddeutschland. Nagra Arbeitsbericht, NAB 13–63, 1247.
Wagner, B., Toumlpfner, C., Lischeid, G., Scholz, M., Klinger, R. & Klaas, P. (2003) Hydrogeochemische Hintergrundwerte der Grundwässer Bayerns. GLAFachberichte, 21, 1250.
Zorlu, J. (2007) Sedimentpetrographische und geochemische Untersuchungen an unterschiedlich überprägten Triasdolomiten der Ost- und Südalpen. Doctoral thesis. Ruhr-Universität Bochum, Germany, 180 pp.

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A strontium isotope and trace element geochemical study of dolomite-bearing bentonite deposits in Bavaria (Germany)

  • Mathias H. Köster (a1), Stefan Hölzl (a2) and H. Albert Gilg (a1)

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