This study focuses on a detailed facies analysis of the Pļaviņas Formation (Upper Devonian, Lower Frasnian) and the interpretation of their sedimentary environments. The study area is located in the northwestern part of the Main Devonian Field, including the territory of Latvia and the southeastern part of Estonia. Facies analyses primarily rely on geological section documentation, macro-scale sample studies, and various methods, such as X-ray diffraction, X-ray fluorescence, total organic carbon analysis, biomarker analysis, and carbon and oxygen stable isotope analysis. Shallow-water sedimentation occurs across all studied areas of the Baltic Devonian Basin. The basin territory exhibits multiple areas with diverse hydrodynamic activities, leading to fluctuations in environmental energy levels during the study period. Notably, the lagoonal to tidal flat environment is particularly related to the northeastern part of the study area, especially within the Sēlija and Atzele members of the Pļaviņas Formation.
Amthor, J. E., Mountjoy, E. W. and Machel, H. G. 1993. Subsurface dolomites in Upper Devonian Leduc build-ups, central part of Rimbey-Medowbrook reef trend, Alberta, Canada. Bulletin of Canadian Petroleum Geology, 41, 164–184.
Azami, S. H., Wagreich, M., Mehrizi, M. M., Gharaie, M. H. M., Gier, S. and Leckie, R. M. 2021. Sedimentology and sediment geochemistry of the pelagic Paryab section (Zagros Mountains, Iran): implications for sea level fluctuations and paleoenvironments in the late Paleocene to middle Eocene. Arabian Journal of Geosciences, 14, 1032.
https://doi.org/10.1007/s12517-021-07291-0
Brangulis, A., Kuršs, V., Misāns, J. and Stinkulis, Ģ. 1998. Latvijas ģeoloģija (Geology of Latvia). Valsts ģeoloģijas dienests, Riga.
Chow, N. and Wendte, J. 2011. Palaeosols and palaeokarst beneath subaerial unconformities in an Upper Devonian isolated reef complex (Judy Creek), Swan Hills Formation, west-central Alberta, Canada. Sedimentology, 58(4), 960–993.
https://doi.org/10.1111/j.1365-3091.2010.01191.x
Colombié, C., Lécuyer, C. and Strasser, A. 2010. Carbon- and oxygen-isotope records of paleoenvironmental and carbonate production changes in shallow-marine carbonates (Kimmeridgian, Swiss Jura). Geological Magazine, 148(1), 133–153.
https://doi.org/10.1017/S0016756810000518
De Vleeschouwer, D., Da Silva, A. C., Boulvain, F., Crucifix, M. and Claeys, P. 2011. 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
Flügel, E. 2004. Microfacies of Carbonate Rocks: Analysis, Interpretation and Application. Springer, Berlin, Heidelberg.
Garland, J. 1997. Middle to Upper Devonian (Givetian and Frasnian) shallow-water carbonates of western Europe: facies analysis and cyclicity. PhD thesis. University of Durham, UK.
Gravītis, V. A. 1967. О фациальных изменений карбонатной части франского яруса в Гулбенской впадине и на ее северном и восточном обрамлении (About facies changes in the Carboniferous of the Frasnian Stage in Gulbene Syncline and its northern and eastern parts). In Вопросы геологии среднего и верхнего палеозоя Прибалтики (On Questions of the Geology of the Middle and Upper Paleozoic of the Baltic) (Egorova, D. F., ed.). Zinātne, Riga‚ 54–84.
Guangquan, Z. and Lidong, M. 2021. Sedimentary facies of clastic-platform carbonate sediment strata of epicontinental sea in the Daniudi Gasfield, Ordos Basin. Natural Gas Industry B, 8(3), 239–251.
https://doi.org/10.1016/j.ngib.2021.04.002
Immenhauser, A. 2009. Estimating palaeo-water depth from the physical rock record. Earth-Science Reviews, 96(1–2), 107–139.
https://doi.org/10.1016/j.earscirev.2009.06.003
Irwin, M. L. 1965. General theory of epeiric clear water sedimentation. AAPG Bulletin, 49(4), 445–459.
https://doi.org/10.1306/A6633632-16C0-11D7-8645000102C1865D
James, N. P. and Jones, B. 2015. Origin of Carbonate Sedimentary Rocks. John Wiley & Sons.
Kleesment, A., Urtson, K., Kiipli, T., Martma, T., Põldvere, A., Kallaste, T. et al. 2013. Temporal evolution, petrography, and composition of dolostones in the Upper Devonian Plavinas Regional Stage, southern Estonia and northern Latvia. Estonian Journal of Earth Sciences, 62(3), 139–159.
https://doi.org/10.3176/earth.2013.12
Land, L. S. 1980. The isotopic and trace element geochemistry of dolomite: the state of the art. In Concepts and Models of Dolomitization (Zenger, D. H., Dunham, J. B. and Ethington, R. L., eds). Society of Economic Paleontologists and Mineralogists (SEPM), Special Publication, 28, 87–110, Tulsa, Oklahoma.
https://doi.org/10.2110/pec.80.28.0087
Li, F., Gong, Q., Burne, R. V., Tang, H., Su, C., Zeng, K. et al. 2019. Ooid factories operating under hothouse conditions in the earliest Triassic of South China. Global and Planetary Change, 172, 336–354.
https://doi.org/10.1016/j.gloplacha.2018.10.012
Liepiņš, P. P. 1963. Условия формирования франских отложений Прибалтики (Conditions for the formation of Frasnian deposits in the Baltic region). In Франские отложения Латвийской ССР (Stratigraphy of Frasnian Deposits of the Latvian SSR). Riga‚ 311–337.
Lukševičs, E., Ahlberg, P. E., Stinkulis, Ģ., Vasiļkova, J. and Zupiņš, I. 2011. Frasnian vertebrate taphonomy and sedimentology of macrofossil concentrations from the Langsēde Cliff, Latvia. Lethaia, 45(3), 356–370.
https://doi.org/10.1111/j.1502-3931.2011.00288.x
Mackensen, A. and Schmiedl, G. 2019. Stable carbon isotopes in paleoceanography: atmosphere, oceans, and sediments. Earth-Science Reviews, 197, 102893.
https://doi.org/10.1016/j.earscirev.2019.102893
Masse, J. P., Fenerci, M. and Pernarcic, E. 2003. Palaeobathymetric reconstruction of peritidal carbonates: Late Barremian, Urgonian, sequences of Provence (SE France). Palaeogeography, Palaeoclimatology, Palaeoecology, 200(1–4), 65–81.
https://doi.org/10.1016/S0031-0182(03)00445-0
Mešķis, S. 2013. Pēdu fosiliju kompleksi galvenā devona lauka Franas stāva nogulumos (Ichnofossil complexes in main Devonian field rocks of Frasnian). Dissertation. Dissertationes geologicae Universitas Latviensis, 26. University of Latvia, Latvia.
Messadi, A. M., Mardassi, B., Ouali, J. A. and Touir, J. 2016. Sedimentology, diagenesis, clay mineralogy and sequential analysis model of Upper Paleocene evaporite-carbonate ramp succession from Tamerza area (Gafsa Basin: southern Tunisia). Journal of African Earth Sciences, 118, 205–230.
https://doi.org/10.1016/j.jafrearsci.2016.02.020
Nichols, G. 1999. Sedimentology and Stratigraphy. Blackwell Science, Oxford.
Pontén, A. and Plink-Björklund, P. 2007. Depositional environments in an extensive tide-influenced delta plain, Middle Devonian Gauja Formation, Devonian Baltic Basin. Sedimentology, 54(5), 969–1006.
https://doi.org/10.1111/j.1365-3091.2007.00869.x
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
Pratt, B. R. and James, N. P. 1986. The St George Group (Lower Ordovician) of western Newfoundland: tidal flat island model for carbonate sedimentation in shallow epeiric seas. Sedimentology, 33(3), 313–343.
https://doi.org/10.1111/j.1365-3091.1986.tb00540.x
Reading, H. G. and Collinson, J. D. 1996. Clastic coasts. In Sedimentary Environments: Processes, Facies and Stratigraphy (Reading, H. G., ed.). Blackwell Science, Oxford, 154–231.
Sharp, Z. D. 2017. Principles of Stable Isotope Geochemistry. Pearson/Prentice Hall, Upper Saddle River.
Sorokin, V. 1978. Этапы развития Северо-Запада Русской платформы во Франском веке (Stages of Development of the North-Western Part of the Russian Platform in the Frasnian). Zinātne, Riga.
Sorokin, V. 1997. Pļaviņu svīta (Pļaviņu Formation). In Enciklopēdija Latvijas daba (Encyclopedia Latvian Nature). 4th ed. Preses nams, Riga, 160–167.
Stinkulis, Ģ. and Lukševičs, E. 2018. Devona un karbona sedimentācijas baseini (Sedimentary basins of Devonian and Carboniferous). In Latvija. Zeme, daba, tauta, valsts (Latvia. Earth, Nature, People, Country) (Nikodemus, O., Kļaviņš, M., Krišjāne, Z. and Zelčs, V., eds). LU Akadēmiskais apgāds, Riga, 154–160.
Stinkulis, Ģ., 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
Tänavsuu-Milkeviciene, K. and Plink-Björklund, P. 2009. Recognizing tide-dominated versus tide-influenced deltas: Middle Devonian strata of the Baltic Basin. Journal of Sedimentary Research, 79(12), 887–905.
https://doi.org/10.2110/jsr.2009.096
Tucker, M. E. and Garland, J. 2010. High-frequency cycles and their sequence stratigraphic context: orbital forcing and tectonic controls on Devonian cyclicity, Belgium. Geologica Belgica, 13(3), 213–240.
Tucker, M. E. and Wright, V. P. 1990. Carbonate Sedimentology. Blackwell Science, Oxford.
https://doi.org/10.1002/9781444314175
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
Xu, Y., Hu, X., Garzanti, E., Sun, G., Jiang, J., Li, J. et al. 2023. Carbonate factories and their critical control on the geometry of carbonate platforms (mid-Cretaceous, southern Iran). Palaeogeography, Palaeoclimatology, Palaeoecology, 635, 111680.
https://doi.org/10.1016/j.palaeo.2023.111680