Zeolity mineralizovana dreva
v laharu Soutesky u Decina

Fossil flora imprints have been found during remediation works on the road no. 262 Děčín – Benešov nad Ploučnicí, running through Soutěsky Pass and cutting through a lahar sequence of the České středohoří Volcanic Complex by the remediation company employee. The exposed lahar sequence belongs to the Děčín Fm. (sensu Cajz 2000), where Oligocene flora has been recently found at a nearby locality (Teodoridis et al. 2020). Subsequent field campaign at the Soutěsky outcrop focused on documentation of the lahar deposits and collection of permineralized wood fragments. The outcrop was mapped in detail and photographed for later interpretations. Samples from selected wood pieces were thin-sectioned for anatomical studies and prepared for powder X-ray diffraction and micro-probe analyses.

Late Oligocene woods at the Soutěsky locality were mineralized with a mixture of zeolites belonging to the Ca-K mineralization series [predominantly phillipsite-(Ca) and chabazite-(Ca)] representing the alkaline to intermediate members of the zeolite group. The zeolites are present mainly in the cell fillings, whereas a mineral of the smectite group (belonging to the K mineralization series) was identified on the cell walls. Scarce analcime was identified by powder X-ray diffraction analysis together with a slightly more abundant thomsonite (Na-Ca mineralization series). The observed mineral assemblage corresponds to the low temperature of hydrothermal fluids at very low pressures, which suggests that the mineralization proceeded very close to the surface, probably only in the presence of meteoric water which permeated the lahar sequence. Such zeolite mineralization series are common in the continental rift environment. However, complete zeolite permineralization of fossil wood in the alkaline volcanic rocks is less common than carbonate permineralization. The observed association corresponds to the low temperature of hydrothermal solutions at very low pressures. Two taxa were identified among the collected samples of permineralized woods. The predominant type is represented by Taxodioxylon gypsaceum. A single fragment was identified as Platanoxylon sp., which represents the very first find of fossil wood of this species in the České středohoří Volcanic Complex. In addition to these two wood taxa, imprints of deciduous trees were also found at the outcrop, but their mode of preservation did not allow any closer species identification.

References

Bish, D. L. – Post, J. E. (1989): Quantitative analysis, in Modern Powder Diffraction. – Econ. Geol. 74, 888–901.

Bruker AXS (2014): Topas 5. – Karlsruhe.

Bruker AXS (2015): Diffrac.Eva, 4.1. – Karlsruhe.

Cajz, V. (2000): Proposal of lithostratigraphy for the České středohoří Mts volcanics. – Bull. Czech Geol. Surv. 75, 7–16.

Dvořák, Z. – Mach, K. – Dvořák, P. (2015): Jezero mezi sopkami, Kučlín u Bíliny. – 119 str. Bílinská přírodověd. spol., o. s. Bílina.

Dvořák, Z. – Radoň, M. (2009): Zkamenělá dřeva Českého středohoří. – Minerál 17, 2, 156–158.

FIZ (2019): ICSD database. – Fachinform. Zentrum. Karlsruhe.

IAWA Committee (1989): IAWA list of microscopic features for hardwood identification. – IAWA Bull. 10, 3, 219–332.

IAWA Committee (2004): IAWA list of microscopic features for softwood identification. – IAWA J. 25, 1, 1–70.

ICDD (2018): Powder Diffraction File (PDF-2 2018) – Int. Center for Diffract. Data. Newtown Square, Pennsylvania.

Koutecký, V. – Sakala, J. (2015): New fossil woods from the Paleogene of Doupovské hory and České středohoří Mts. (Bohemian Massif, Czech Republic). – Sbor. Nár. Muz. (Praha), Ř. B 71, 3–4, 377–398.

Koutecký, V. – Teodoridis, V. – Čáp, P. – Mantzouka, D. – Sakala, J. (2019): Fossil wood from the Doupovské hory and České středohoří volcanic complexes: latest overview and new angiosperms from the locality Dvérce. – Neu. Jb. Geol. Paläont. 293, 3, 283–306.

Kräusel, R. (1949): Die fossilen Koniferen-Hölzern (Unter Ausschluss von Araucarioxylon Kraus). – II. Teil. Kritische Untersuchungen zur Diagnostik lebender und fossiler Koniferen- Hölzer. – Palaeontographica, Abt. B (Stuttgart) 89, 83–203.

Kvaček, Z. – Teodoridis, V. (2007): Tertiary macrofloras of the Bohemian Massif: a review with correlations within Boreal and Central Europe. – Bull. Geosci. 82, 4, 383–408.

Kvaček, Z. – Walther, H. (2004): Oligocene flora of Bechlejovice at Děčín from the neovolcanic area of the České středohoří Mountains, Czech Republic. – Acta Mus. Nationalis Pragae, B 60, 1–2, 9–60.

Matysová, P. – Götze, J. – Leichmann, J. – Škoda, R. – Strnad, L. – Drahota, P. – Grygar, T. M. (2016): Cathodoluminescence and LA-ICP-MS chemistry of silicified wood enclosing wakefieldite–REEs and V migration during complex diagenetic evolution. – Eur. J. Mineral. 28, 5, 869–887.

Metcalfe, C. R. – Chalk, L. (1950): Anatomy of the dicotyledons, vol. I–II. – 1500 str. Clarendon Press. Oxford.

Mustoe, G. E. (2015): Late Tertiary petrified wood from Nevada, USA: Evidence of multiple silicification pathways. – Geosciences 5, 286–309.

Prakash, U. – Březinová, D. – Bůžek, Č. (1971): Fossil woods from the Doupovské hory and České středohoří Mountains in North Bohemia. – Palaeontographica, Abt. B (Stuttgart) 133 (4–6), 103–128.

Radoň, M. (2001): Výzkum terciérních paleontologických lokalit v Českém středohoří. – 380 str. MS Závěr. zpr. program. projektu MK ČR, Region. muz. v Teplicích. Teplice.

Rapprich, V. – Cajz , V. – Kycl, P. – Suchý, J. – Radoň, M. (2010): New observations on style of volcanic activity of the Děčín Formation, based on temporary exposures during the D8 highway construction near Radejčín (in Czech with English abstract). – Geosci. Res. Rep. 43, 39–42.

Román-Jord án, E. – Esteban, L. G. – de Palacios, P. – Fernández, F. G. (2017): Comparative wood anatomy of the Cupressaceae and correspondence with phylogeny, with special reference to the monotypic taxa. – Plant System. Evol. 303, 2, 203–219.

Sakala, J. – Rapprich, V. – Pécskay, Z. (2010): Fossil angiosperm wood and its host deposits from the periphery of a dominantly effusive ancient volcano (Doupovské hory Volcanic Complex, Oligocene-Lower Miocene, Czech Republic): systematics, volcanology, geochronology and taphonomy. – Bull. Geosci. 85, 4, 617–629.

Soukupová, H. (2004): Vegetace a paleoekologie vybraných lokalit Českého středohoří. – 105 str. MS diplom. práce, Univerzita Karlova. Praha.

Süss, H. (2007): Holzfossilien der Morphogattung Spiroplatanoxylon gen. nov. aus dem Tertiär von Europa und Vorderasien. – Feddes Repert. 118, 1–2, 1–19.

Süss, H. – Müller-Stoll, W. R. (1977): Untersuchungen über fossile Platanhölzer. Beiträge zu einer Monographie der Gattung Platanoxylon Andreánszky. – Feddes Repert. 88, 1–2, 1–62.

Teodoridis, V. – Kvaček, Z. – Radoň, M. – Rapprich, V. – Bruch, A. A. (2020): A new Oligocene Flora from Ludvíkovice near Děčín (České středohoří Mts., the Czech Republic). – Foss. Imprint 76, 2, 297–314.

Teodoridis, V. – Sakala, J. (2008): Early Miocene conifer macrofossils from the Most Basin (Czech Republic). – Neu. Jb. Geol. Paläont. 250, 3, 287–312.

Utada, M. (1980): Hydrothermal alterations related to igneous activity in Cretaceous and Neogene formations of Japan. – Min. Geol. Spec. Issue 8, 67–83.

Utada, M. (2001): Zeolites in Hydrothermally Altered Rocks. – Natural Zeolites: Occurrence, Properties, Application. – Rev. Mineral. Geochem. 45, 305–322