The Csehbánya Formation is a

geological formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

in the Transdanubian Mountains of

Veszprém County Veszprém ( hu, Veszprém megye, ; german: Komitat Wesprim (Weißbrunn)) is an administrative county (''megye'') in Hungary. Veszprém is also the name of the capital city of Veszprém county. Veszprém county Veszprém county lies in western ...

Hungary Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Cr ...

. The formation dates to the Late

Santonian The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya. ...

(around 85-84 million years ago) of the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

. It represents a floodplain environment as opposed to the swampy lacustrine environment of the simultaneous Ajka Coal Formation, though there is complete overlap in terms of

fauna Fauna is all of the animal life present in a particular region or time. The corresponding term for plants is '' flora'', and for fungi, it is '' funga''. Flora, fauna, funga and other forms of life are collectively referred to as '' biota''. ...

. It underlies the Jákó Marl Formation, and laterally transitions to the Ajka Coal Formation.

Geology

The

lithology The lithology of a rock unit is a description of its physical characteristics visible at outcrop, in hand or core samples, or with low magnification microscopy. Physical characteristics include colour, texture, grain size, and composition. Li ...

of the unit is a cyclic variation of conglomerate, sandstone, variegated siltstone, clay and marl layers with some sporadic thin coal seams. It is unconformably overlies the

Late Triassic The Late Triassic is the third and final epoch of the Triassic Period in the geologic time scale, spanning the time between Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch and followed by the Early Jurassic Epoch ...

Main Dolomite Formation, which has deposits of the

Upper Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

Nagytárkány Bauxite Formation within deep

karst Karst is a topography formed from the dissolution of soluble rocks such as limestone, Dolomite (rock), dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathe ...

ic sinkholes in the formation. There is a basal conglomerate of dolomite clasts at the base of the Csehbánya formation. The main exposed portion of the formation is called the Iharkút locality, which is a disused

bauxite Bauxite is a sedimentary rock with a relatively high aluminium content. It is the world's main source of aluminium and gallium. Bauxite consists mostly of the aluminium minerals gibbsite (Al(OH)3), boehmite (γ-AlO(OH)) and diaspore (α-AlO ...

quarry. At this location due to Paleogene uplift, it is unconformably overlain by the

Lutetian The Lutetian is, in the geologic timescale, a stage or age in the Eocene. It spans the time between . The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it is sometimes referred to as the ...

Ikharkút Conglomerate. In the upper levels of the formation, there are sandstone lens beds present, which represent channel bodies. These are indicative of an

anastomosing An anastomosis (, plural anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf veins, or streams. Such a connection may be normal ...

fluvial system. The exposure at this locality is between 100–150 m. Most of the fossils are found within the SZ-6 site at the locality, which is interpreted as a lag channel deposit

Invertebrate paleofauna

Amber is known from both the Ajka Coal and Csehbánya Formations, and is commonly referred to as ajkait. However most of the arthropod inclusions in these are undescribed, only being shown in photographs, With only two species of Ceratopogonids (biting midges) in the extant genus '' Leptoconops'' and the extinct genus ''Adelohelea'' being described. A list of known taxa is given below.

Vertebrate paleofauna

Csehbanya Formation representative fauna

Fishes, amphibians, turtles, squamates, crocodilians, dinosaurs,Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, Europe)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 588-593. . birds and pterosaurs present in Veszprém, Hungary, near the village of Németbánya in the Iharkút locality, an

open-pit Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique of extracting rock or minerals from the earth from an open-air pit, sometimes known as a borrow. This form of mining ...

mine.Makádi, L., Botfalvai, G., Ősi, A. 2006: Egy késő-kréta kontinentális gerinces fauna a Bakonyból: halak, kétéltűek, teknősök, gyíkok. Földtani Közlöny 136/4, pp. 487-502. Other finds include

Abelisauridae Abelisauridae (meaning "Abel's lizards") is a family (or clade) of ceratosaurian theropod dinosaurs. Abelisaurids thrived during the Cretaceous period, on the ancient southern supercontinent of Gondwana, and today their fossil remains are fou ...

indet.,

Rhabdodontidae Rhabdodontidae is a family of herbivorous iguanodontian ornithopod dinosaurs whose earliest stem members appeared in the middle of the Lower Cretaceous. The oldest dated fossils of these stem members were found in the Barremian Castrillo de la Re ...

indet.,Ősi, A. & Rabi, M., 2006. Egy késő-kréta kontinentális gerinces fauna a Bakonyból II.: krokodilok, dinoszauruszok, pteroszauruszok és madarak (The Late Cretaceous continental vertebrate fauna from the Bakony Mountains II: crocodiles, dinosaurs (Theropoda, Aves, Ornithischia), pterosaurs). Földtani Közlöny, 136, 4, 503–526.

Tetanurae Tetanurae (/ˌtɛtəˈnjuːriː/ or "stiff tails") is a clade that includes most theropod dinosaurs, including megalosauroids, allosauroids, tyrannosauroids, ornithomimosaurs, compsognathids and maniraptorans (including birds). Tetanurans ar ...

indet. Coprolites and eggshells are also known from the locality.

Fish

Amphibians

Squamates

Crocodyliformes

Turtles

Pterosaurs

Non-avian dinosaurs

Birds

References

{{DEFAULTSORT:Csehbanya Formation Geologic formations of Hungary Upper Cretaceous Series of Europe Santonian Stage Siltstone formations Sandstone formations Conglomerate formations Alluvial deposits Fluvial deposits Fossiliferous stratigraphic units of Europe Paleontology in Hungary