The Lava Formation is a Mesozoic geologic formation in Lithuania and Kaliningrad, being either the sister or the same unit as the Ciechocinek Formation. It represents the outcrop of Lower Toarcian layers in the Baltic Syncline and in the Lithuanian-Polish Syneclise (C8-borehole in Gdańsk Bay). It is known by the presence of Miospores and Pollen, as well Plant remains. The formation contains grey, greenish, and dark grey silt and clay with interealatians and lenses of fine-grained sand, pyritic concretions and plant remains (carbonised wood fragments). The Jotvingiai Group Toarcian deposits represent deposits laid down in fresh water and brackish basins, possibly lagoons or coastal plain lakes. The Bartoszyce IG 1 of the Ciechocinek Formation shows how at the initial phase of the Toarcian there was a regional transgression in the Baltic Syncline, indicated by greenish-grey mudstones, heteroliths and fine-grained sandstones with abundant plant fossils and plant roots, what indicates a local delta progradation between the Lava and Ciechocinek Fms. Then a great accumulation of miospores (+2500 specimens) indicates a local concentration, likely due to a rapidly decelerating fluvial flow in a delta-fringing lagoon forming a “hydrodynamic trap”, with the wave and currents stopping the miospores to spread to the basin. Latter a marsh system developed with numerous palaeosol levels, being overlaid by brackish-marine embayment deposits that return to lagoon-marsh facies with numerous plant roots (Radicites sp) and palaeosol levels in the uppermost section, ending the succession. Overall the facies show that the local Ciechocinek-Lava system was a sedimentary basin shallow and isolated, surrounded by a flat coastal/delta plain with marshes, delivering abundant spores and Phytoclasts, indicators of proximal landmasses with high availability of wood and other plant material. This climate at the time of deposition was strongly seasonal, probably with monsoonal periods. Due to the abundant presence of deltaic sediments on the upper part, it is considered to be related to the retry of the sea level. The Lava Formation was deposited on a mostly continental setting, with its upper part, dominated by argillaceous sediments, corresponding to the Ciechocinek Formation. There is a great amount of kaolinite content, being present laterally in the basin, decreasing and lifting space to increasing smectite to the south-west of the formation. On the other hand, there is a great amount of coarsest sediments, which consist mostly of sands.
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Palynology Genus Species Stratigraphic position Material Notes ImagesLeiotriletesLeiotriletes rotundiformisNida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholeMiosporesAffinities with Botryopteridaceae, Cooksoniaceae, Schizaeaceae, Sermayaceae and Zosterophyllaceae. Likely reworked from Devonian-Permian layersAcanthotriletesAcanthotriletes elatusNida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholeMiosporesAffinities with the Botryopteridaceae and Selaginellaceae. Reworked from primitive ferns found in Devonian and Carboniferous rocks of EuropeStaplinisporitesStaplinisporites caminusNida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholeMiosporesAffinities with the family Encalyptaceae inside Bryopsida. Branching Moss Spores, related with high water-depleting environmentsLycopodiumsporitesLycopodiumsporites semimurisNida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholeMiosporesAffinities with the family Lycopodiaceae inside Lycopodiopsida.FoveosporitesFoveosporites microreticulatusNida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholeMiosporesAffinities with the family Lycopodiaceae inside Lycopodiopsida. Lycopod spores, related with herbaceous to arbustive flora common on humid environmentsUvaesporitesUvaesporites argenteaeformisNida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholeMiosporesAffinities with the Selaginellaceae inside Lycopsida.DensoisporitesDensoisporites crassusNida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholeMiosporesAffinities with the Selaginellaceae inside Lycopsida. Relatively abundantHeliosporitesHeliosporites altmarkensisNida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholeMiosporesAffinities with the Selaginellaceae inside Lycopsida. Herbaceous Lycophyte flora, similar to Ferns, related with Humid Settings. This Family of Spores are also the most diverse on the Formation.LeiozonotriletesLeiozonotriletes sp sp. nov.Nida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholeMiosporesUncertain Affinities with the Pteridopsida.CingulatisporitesCingulatisporites scabratus Cingulatisporites sp sp. nov.Nida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholeMiosporesAffinities with Cibotiaceae and Selaginellaceae inside Pteridopsida. Relatively abundantLeptolepiditesLeptolepidites major Leptolepidites sp sp. nov.Nida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholeMiosporesAffinities with the family Dennstaedtiaceae inside Polypodiales. Forest Fern SporesPilosisporitesPilosisporites brevipapillosusNida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholeMioporesAffinities with Schizaeaceae and Lygodiaceae inside Pteridophyta. Either from herbaceous or climbing fernsKlukisporitesKlukisporites sp sp. nov.Nida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 Borehole C8-boreholeMiosporesAffinities with the family Lygodiaceae inside Polypodiopsida. Climbing fern sporesClathropterisosporaClathropterisospora obovata Clathropterisospora "sp. 1" Clathropterisospora "sp. 2"Nida-44 Borehole Kybartai-29 BoreholeMiosporesAffinities with Dipteridaceae inside Polypodiales. DictyophylliditesDictyophyllidites sp sp. nov.Uljanovo-3 Borehole Kybartai-29 BoreholeMiosporesAffinities with Dipteridaceae inside Polypodiales. Dictyophyllum is a common Dipteridacean genus of the mid-Mesozoic MarattiopsisMarattiopsis scabratusNida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholeMiosporesAffinities with the Marattiaceae inside Polypodiopsida. MatonisporitesMatonisporites phlebopteroidesNida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholeMioporesAffinities with the Matoniaceae inside Polypodiopsida. Fern spores from lower herbaceous flora CyathiditesCyathidites minorNida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholeMiosporesAffinities with the family Cyatheaceae inside Cyatheales. Arboreal Fern Spores TripartinaTripartina variabilis Tripartina sp sp. nov.Nida-44 Borehole C8-boreholeMiosporesAffinities with Dicksoniaceae inside Cyatheales. Common cosmopolitan Mesozoic Tree fern genus. CamptotriletesCamptotriletes anagrammensis Camptotriletes cerebriformis Camptotriletes triangularisNida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholeMiosporesAffinities with the Lepidodendraceae and Botryopteridaceae. Reworked Carboniferous PalynomorphsHymenozonotriletesHymenozonotriletes dalinkevidiusi Hymenozonotriletes speciosusNida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholeMiosporesAffinities with the Lepidodendraceae. ReworkedProtopinusProtopinus sp sp. nov.Nida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholePollenPollen from the Family Caytoniaceae inside Caytoniales. Caytoniaceae are a complex group of Mesozoic Fossil floras, that can be related to both Peltaspermales and Ginkgoaceae.ChasmatosporitesChasmatosporites apertus Chasmatosporites hians Chasmatosporites sp.Nida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 Borehole C8-boreholeAffinities with the family Cycadaceae inside Cycadales. Is among the most abundant flora recovered on the upper section of the coeval Rya Formation, and was found to be similar to the pollen of the extant Encephalartos laevifolius.PaleoconiferusPaleoconiferus sp sp. nov.Nida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholePollenAffinities with the Voltziaceae, Pinaceae, Cupressaceae and Araucariaceae inside Pinopsida. PseudopinusPseudopinus oblatinoidesNida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholePollenAffinities with the Voltziaceae inside Pinopsida.ProtopodocarpusProtopodocarpus sp sp. nov.Nida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholePollenAffinities with the Voltziaceae inside Pinopsida.PaleopiceaPaleopicea sp sp. nov.Nida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholePollenAffinities with the Pinaceae and Voltziaceae inside Pinopsida.PseudopiceaPseudopicea sp. sp. nov.Nida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 BoreholePollenAffinities with the Pinaceae inside Pinopsida. Relatively abundant Pinaceae Pollen, appears specially on Kaolinite-abundant strata. CerebropollenitesCerebropollenites dalinkeviciusiNida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 Borehole C8-boreholePollenAffinities with the Sciadopityaceae or Miroviaceae inside Coniferales. This Pollen resemblance with extant Sciadopitys suggest that Miroviaceae can be an extinct lineage of sciadopityaceaous-like plants. PerinopollenitesPerinopollenites sp sp. nov.Nida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 Borehole C8-boreholePollenAffinities with the family Cupressaceae inside Pinopsida. Pollen that resembles extant genera such as the Genus Actinostrobus and Austrocedrus, probably derived from Dry environments.CupressacitesCupressacites coriaceus Cupressacites subgranulatusC8-boreholePollenAffinities with the family Cupressaceae inside Pinopsida.TaxodiitesTaxodiites pallensC8-boreholePollenAffinities with the family Cupressaceae inside Pinopsida.ClassopollisClassopollis corniculatus Classopollis sp.1 sp. nov. Classopollis sp.2 sp. nov. Classopollis sp.3 sp. nov.Nida-44 Borehole Belyj Jar-1 Borehole Uljanovo-3 Borehole Kybartai-29 Borehole C8-boreholePollenAffinities with the Cheirolepidiaceae inside Pinopsida. Indicator of Dry settings
Megaflora Genus Species Stratigraphic position Material Notes ImagesPhlebopterisPhlebopteris cf. smithiiNida-44 BoreholeIsolated pinnaeAffinities with Matoniaceae inside Gleicheniales. GinkgoitesGinkgoites acuta Ginkgoites "sp. 1"Nida-44 Borehole Belyj Jar-1 BoreholeLeaves Affinities with Ginkgoaceae inside Ginkgoales. Large to medium Arboreal trees, common on the Fennoscandinavian realm, but also on the Siberian strataPicea?Picea? sp sp. nov. Picea? sp.1 sp. nov. Picea? sp.2 sp. nov.Nida-44 Borehole Uljanovo-3 BoreholeConesAffinities with the Piceoideae inside Coniferales. Pinus?Pinus? sp sp. nov.Nida-44 BoreholeConesAffinities with the Pinaceae inside Coniferales. PodozamitesPodozamites sp sp. nov.Nida-44 BoreholeLeaves Affinities with Krassiloviaceae inside Voltziales. The local Podozamites show a rather great range of Growth, reflecting Tropical to subtropical conditions. ElatocladusElatocladus sp.Nida-44 BoreholeLeavesAffinities with the Cupressaceae inside Coniferales.
See also List of fossiliferous stratigraphic units in Lithuania Toarcian turnover Toarcian formations Marne di Monte Serrone, Italy Calcare di Sogno, Italy Mizur Formation, North Caucasus Djupadal Formation, Central Skane Sachrang Formation, Austria Saubach Formation, Austria Posidonia Shale, Lagerstätte in Germany Ciechocinek Formation, Germany and Poland Krempachy Marl Formation, Poland and Slovakia Azilal Group, North Africa Whitby Mudstone, England Fernie Formation, Alberta and British Columbia Poker Chip Shale Whiteaves Formation, British Columbia Navajo Sandstone, Utah Los Molles Formation, Argentina Mawson Formation, Antarctica Kandreho Formation, Madagascar Kota Formation, India