Siliciclastic deposits and dolostones of the Šķervelis Formation in southwestern Latvia were studied in outcrops, polished slabs, thin sections, and by geochemical methods, including stable isotope analyses. Siliciclastic fluvial deposits alternate with soils and carbonates. As the soil processes became dominant, up to 6 m thick dolocretes formed, but they still preserve remnant sedimentary structures and textures. The strong role of soil processes is indicated by the presence of ooids and pisoids together with fine laminar layers, chert and phosphatic inclusions, rhizoids, and stable isotope values. Peculiar vertical clay-dolomite structures, up to 1.7 m long, are root structures or their combination with Vertisol-like soil development. The extensive development of soil processes and formation of the vertical structures was stimulated by seasonally wet monsoon climate. The scarcity of fossils in the studied deposits does not allow their age to be determined precisely, but probably the thick dolocrete unit in the upper part of the studied succession formed during the end-Devonian glaciation and the period of related sea regression.
Algeo, T. J., Scheckler, S. E. and Maynard, J. B. 2001. Effects of the Middle to Late Devonian spread of vascular land plants on weathering regimes, marine biotas, and global climate. In Plants Invade the Land, Evolutionary and Environmental Perspectives (Gensel, P. G. and Edwards, D., eds). Columbia University Press, New York, Chichester, 213–236.
https://doi.org/10.7312/gens11160-013
Alonso-Zarza, A. M. 2003. Palaeoenvironmental significance of palustrine carbonates and calcretes in the geological record. Earth Science Reviews, 60(3–4), 261–298.
https://doi.org/10.1016/S0012-8252(02)00106-X
Beck, C. B. 1981. Archaeopteris and its role in vascular plant evolution. In Paleobotany, Paleoecology, and Evolution (Niklas, K. J., ed.). Praeger, New York, 193–230.
Birger, L. 1979. Каменноугольная система (Carboniferous System). In Геологическое строение и полезные ископаемые Латвии (Geological Structure and Mineral Deposits of Latvia) (Misans, J., ed.). Zinatne, Riga, 163–167.
Brand, U., Legrand-Blain, M. and Steel, M. 2004. Biochemostratigraphy of the Devonian–Carboniferous boundary global stratotype section and point, Griotte Formation, La Serre, Montagne Noire, France. Palaeogeography, Palaeoclimatology, Palaeoecology, 205(3–4), 337–357.
https://doi.org/10.1016/j.palaeo.2003.12.015
Candy, I., Black, S. and Sellwood, B. W. 2004. Quantifying time scales of pedogenic calcrete formation using U-series disequilibria. Sedimentary Geology, 170(3–4), 177–187.
https://doi.org/10.1016/j.sedgeo.2004.07.003
Casado, A. I., Alonso-Zarza, A. M. and La Iglesia, A. 2014. Morphology and origin of dolomite in paleosols and lacustrine sequences. Examples from the Miocene of the Madrid Basin. Sedimentary Geology, 312, 50–62.
https://doi.org/10.1016/j.sedgeo.2014.07.005
Dawit, E. L. 2016. Paleoclimatic records of Late Triassic paleosols from Central Ethiopia. Palaeogeography, Palaeoclimatology, Palaeoecology, 449, 127–140.
https://doi.org/10.1016/j.palaeo.2016.02.011
De Vleeschouwer, D., Da Silva, A. C., Boulvain, F., Crucifix, M. and Claeys, P. 2012. Precessional and half-precessional climate forcing of Mid-Devonian monsoon-like dynamics. Climate of the Past, 8(1), 337–351.
https://doi.org/10.5194/cp-8-337-2012
De Vleeschouwer, D., Crucifix, M., Bounceur, N. and Claeys, P. 2014. The impact of astronomical forcing on the Late Devonian greenhouse climate. Global and Planetary Change, 120, 65–80.
https://doi.org/10.1016/j.gloplacha.2014.06.002
Díaz-Hernández, J. L., Sánchez-Navas, A. and Reyes, E. 2013. Isotopic evidence for dolomite formation in soils. Chemical Geology, 347, 20–33.
https://doi.org/10.1016/j.chemgeo.2013.03.018
DiMichele, W. A. C., Cecil, B., Montañez, I. P. and Falcon-Lang, H. J. 2010. Cyclic changes in Pennsylvanian paleoclimate and effects on floristic dynamics in tropical Pangaea. International Journal of Coal Geology, 83(2–3), 329–344.
https://doi.org/10.1016/j.coal.2010.01.007
Driese, S. G. and Mora, C. I. 2001. Diversification of Siluro–Devonian plant traces in paleosols and influence on estimates of paleoatmospheric CO2 levels. In Plants Invade the Land: Evolutionary and Environmental Perspectives (Gensel, P. G. and Edwards, D., eds). Columbia University Press, New York, 237–253.
https://doi.org/10.7312/gens11160-014
Driese, S. G., Mora, C. I. and Elick, J. M. 1997. Morphology and taphonomy of root and stump casts of the earliest trees (Middle to Late Devonian), Pennsylvania and New York, U.S.A. PALAIOS, 12(6), 524–537.
https://doi.org/10.2307/3515409
Esin, D., Ginter, M., Ivanov, A., Lebedev, O., Lukševičs, E., Avkhimovich, V. et al. 2000. Vertebrate correlation of the Upper Devonian and Lower Carboniferous on the East European Platform. Courier Forschungsinstitut Senckenberg, 223, 341–359.
Gailīte, L. I., Kuršs, V., Lukševiča, L., Lukševičs, E., Pomeranceva, R., Savaitova, L. et al. 2000. Legends for Geological Maps of Latvian Bedrock. State Geological Survey of Latvia, Riga.
Goldstein, R. H. 1991. Stable isotope signatures associated with paleosols, Pennsylvanian Holder Formation, New Mexico. Sedimentology, 38(1), 67–77.
https://doi.org/10.1111/j.1365-3091.1991.tb01855.x
Grimes, K. G. 2009. Solution pipes and pinnacles in syngenetic karst. In Karst Rock Features, Karren Sculpturing(Gines, A., Knez, M., Slabe, T. and Dreybrodt, W., eds). Založba ZRC, Ljubljana, 513–523.
Heidari, A., Mahmoodi, S. and Stoops, G. 2008. Palygorskite dominated Vertisols of southern Iran. In New Trends in Soil Micromorphology (Kapur, S., Mermut, A. and Stoops, G., eds). Springer, Berlin, Heidelberg, 137–150.
https://doi.org/10.1007/978-3-540-79134-8_8
Jiménez-Espinosa, R. and Jiménez-Millán, J. 2003. Calcrete development in Mediterranean colluvial carbonate systems from SE Spain. Journal of Arid Environments, 53(4), 479–489.
https://doi.org/10.1006/jare.2002.1061
Kabanov, P. 2021. Early–Middle Devonian paleosols and palustrine beds of NW Canada in the context of land plant evolution and global spreads of anoxia. Global and Planetary Change, 204, 103573.
https://doi.org/10.1016/j.gloplacha.2021.103573
Kaiser, S. I., Aretz, M. and Becker, R. T. 2016. The global Hangenberg crisis (Devonian–Carboniferous transition): review of a first-order mass extinction. Geological Society, London, Special Publications, 423, 387–437.
https://doi.org/10.1144/SP423.9
Kearsey, T., Twitchett, R. J. and Newell, A. J. 2012. The origin and significance of pedogenic dolomite from the Upper Permian of the South Urals of Russia. Geological Magazine, 149(2), 291–307.
https://doi.org/10.1017/S0016756811000926
Kraus, M. J. and Hasiotis, S. T. 2006. Significance of different modes of rhizolith preservation to interpreting paleoenvironmental and paleohydrologic settings: examples from Paleogene paleosols, Bighorn Basin, Wyoming, U.S.A. Journal of Sedimentary Research, 76(4), 633–646.
https://doi.org/10.2110/jsr.2006.052
Kurshs, V. M. 1992. Девонское терригенное осадконакопление на Главном девонском поле (Devonian Terrigenous Deposition in the Main Devonian Field). Zinatne, Riga.
Lebedev, O. and Lukševičs, E. 2018. New materials on Ventalepis ketleriensis Schultze, 1980 extend the zoogeographic area of a Late Devonian vertebrate assemblage. Acta Geologica Polonica, 68(3), 437–454.
Liepiņš, P. P. 1959. Фаменские отложения Прибалтики (Famennian Deposits of the Baltics). Zinatne, Riga.
Lukševičs, E. and Zupiņš, I. 2004. Sedimentology, fauna, and taphonomy of the Pavāri site, Late Devonian of Latvia. Acta Universitatis Latviensis, 679, 99–119.
Lukševičs, E., Stinkulis, Ģ., Mūrnieks, A. and Popovs, K. 2012. Geological evolution of the Baltic Artesian Basin. In Highlights of Groundwater Research in the Baltic Artesian Basin (Dēliņa, A., Kalvāns, A., Saks, T., Bethers, U. and Vircavs, V., eds). University of Latvia, Riga, 7–52.
Melezhik, V. A., Fallick, A. E. and Grillo, S. M. 2004. Subaerial exposure surfaces in a Palaeoproterozoic 13C-rich dolostone sequence from the Pechenga Greenstone Belt: palaeoenvironmental and isotopic implications for the 2330–2060 Ma global isotope excursion of 13C/12C. Precambrian Research, 133(1–2), 75–103.
https://doi.org/10.1016/j.precamres.2004.03.011
Meunier, A. 2005. Clays. Springer, Berlin.
Moore, D. M. and Reynolds, R. C., Jr. 1997. X-Ray Diffraction and the Identification and Analysis of Clay Minerals. 2nd ed. Oxford University Press, New York.
Mora, C. I. and Driese, S. G. 1999. Palaeoclimatic significance and stable carbon isotopes of Palaeozoic red bed paleosols, Appalachian Basin, USA and Canada. In Palaeoweathering, Palaeosurfaces and Related Continental Deposits: International Association of Sedimentologists Special Publication (Thiry, M. and Simon-Coinçon, R., eds), 27, 61–84.
https://doi.org/10.1002/9781444304190.ch3
Nichols, G. 2009. Sedimentology and Stratigraphy. 2nd ed. John Wiley & Sons, Chichester.
Peryt, T. M. 1983. Vadoids. In Coated Grains (Peryt, T. M., ed.). Springer, Berlin, Heidelberg.
https://doi.org/10.1007/978-3-642-68869-0_38
Pontén, A. and Plink-Björklund, P. 2009. Regressive to transgressive transits reflected in tidal bars, Middle Devonian Baltic Basin. Sedimentary Geology, 218(1–4), 48–60.
https://doi.org/10.1016/j.sedgeo.2009.04.003
Poprawa, P., Šliaupa, S., Stephenson, R. and Lazauskiené, J. 1999. Late Vendian–Early Palæozoic tectonic evolution of the Baltic Basin: regional tectonic implications from subsidence analysis. Tectonophysics, 314(1–3), 219–239.
https://doi.org/10.1016/S0040-1951(99)00245-0
Ringrose, S., Huntsman-Mapila, P., Kampunzu, A. B., Downey, W., Coetzee, S., Vink, B. et al. 2005. Sedimentological and geochemical evidence for palaeo-environmental change in the Makgadikgadi subbasin, in relation to the MOZ rift depression, Botswana. Palaeogeography, Palaeoclimatology, Palaeoecology, 217(3–4), 265–287.
https://doi.org/10.1016/j.palaeo.2004.11.024
Robins, C. R., Deurlington, A., Buck, B. J. and Brock-Hon, A. L. 2015. Micromorphology and formation of pedogenic ooids in calcic soils and petrocalcic horizons. Geoderma, 251–252, 10–23.
https://doi.org/10.1016/j.geoderma.2015.03.009
Sánchez-Román, M., Romanek, C. S., Fernández-Remolar, D. C., Sánchez-Navas, A., McKenzie, J. A., Pibernat, R. A. et al. 2011. Aerobic biomineralization of Mg-rich carbonates: Implications for natural environments. Chemical Geology, 281(3–4), 143–150.
https://doi.org/10.1016/j.chemgeo.2010.11.020
Savvaitova, L. S. 1977. Фамен Прибалтики (Famennian in the Baltics). Zinatne, Riga.
Savvaitova, L. S. and Žeiba, S. 1981. Каменноугольная система (Carboniferous System). In Девон и карбон Прибалтики (Devonian and Carboniferous of the Baltics) (Sorokin, V. S., ed.). Zinatne, Riga, 333–340.
Scotese, C. R. 2014. Atlas of Devonian Paleogeographic Maps, Atlas for ArcGIS 4, The Late Paleozoic, Maps 65–72, Mollweide Projection. PALEOMAP Project, Evanston, IL.
Skompski, S. 2017. Stop B2. Northern wall of Ostrowka quarry. In 10th Baltic Stratigraphic Conference, Checiny, 12–14 September 2017. Abstracts and Field Guide. University of Warsaw, Warsaw, 138–142.
Smith, G. L., Dott, R. H., Jr. and Byers, C. W. 1997. Authigenic silica fabrics associated with Cambro-Ordovician unconformities in the Upper Midwest. Geoscience Wisconsin, 16, 25–36.
Sorokin, V. S. 1981. Франский ярус (the Frasnian Stage). In Девон и карбон Прибалтики (Devonian and Carboniferous in the Baltics) (Sorokin, V. S., ed.). Zinatne, Riga, 240–258.
Stinkulis, Ģ. and Spruženiece, L. 2011. Dolocretes as indicators of the subaerial exposure episodes in the Baltic Devonian paleobasin. In The Eigth Baltic Stratigraphical Conference. Abstracts (Lukševičs, E., Stinkulis, Ģ. and Vasiļkova, L., eds). University of Latvia, Riga.
Stinkulis, G., Lukševičs, E. and Reķe, T. 2020. Sedimentology and vertebrate fossils of the Frasnian Ogre Formation, Gurova outcrops, eastern Latvia. Estonian Journal of Earth Sciences, 69(4), 248–261.
https://doi.org/10.3176/earth.2020.18
Tabor, N. J., Myers, T. S. and Michel, L. A. 2017. Sedimentologist’s guide for recognition, description, and classification of paleosols. In Terrestrial Depositional Systems. Deciphering Complexities Through Multiple Stratigraphic Methods (Zeigler, K. E. and Parker, W. G., eds). Elsevier, 165–208.
https://doi.org/10.1016/B978-0-12-803243-5.00004-2
Taylor, J. C. 1991. Computer programs for standardless quantitative analysis of minerals using the full powder diffraction profile. Powder Diffraction, 6(1), 2–9.
https://doi.org/10.1017/S0885715600016778
Theriault, P. A. and Desrochers, A. 1993. Carboniferous calcretes in the Canadian Arctic. Sedimentology, 40(3), 449–465.
https://doi.org/10.1111/j.1365-3091.1993.tb01345.x
Vasiļkova, J., Lukševičs, E., Stinkulis, Ģ. and Zupiņš, I. 2012. Taphonomy of the vertebrate bone beds from the Klūnas fossil site, Upper Devonian Tērvete Formation of Latvia. Estonian Journal of Earth Sciences, 61(2), 105–119.
https://doi.org/10.3176/earth.2012.2.03
Wright, V. P. 1990. Carbonate sediments and limestones: constituents. In Carbonate Sedimentology (Wright, V. P. and Tucker, M. E., eds). Blackwell Science, 1–27.
https://doi.org/10.1002/9781444314175.ch1
Wright, V. P. and Tucker, M. E. 1991. Calcretes: an introduction. In Calcretes (Wright, V. P. and Tucker, M. E., eds).Reprint Series of the International Association of Sedimentologists, Blackwell, Oxford, 2, 1–24.
https://doi.org/10.1002/9781444304497.ch
Zhou, J. and Chafetz, H. S. 2009. Biogenic caliches in Texas: the role of organisms and effect of climate. Sedimentary Geology, 222(3–4), 207–225.
https://doi.org/10.1016/j.sedgeo.2009.09.003
