The Fur Formation is a marine

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 ...

Ypresian In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian ...

( Lower Eocene Epoch, c. 56.0-54.5 Ma) age which crops out in the Limfjord region of

Denmark ) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of Denmark , establish ...

from Silstrup via Mors and Fur to Ertebølle, and can be seen in many cliffs and quarries in the area. The

Diatomite Diatomaceous earth (), diatomite (), or kieselgur/kieselguhr is a naturally occurring, soft, siliceous sedimentary rock that can be crumbled into a fine white to off-white powder. It has a particle size ranging from more than 3 μm to le ...

Cliffs (''moler'' in Danish) is on the Danish list of tentative candidates for

World Heritage A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for ...

and may become a world Heritage site.

Geology

The Fur Formation is a

unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...

of diatomitic sediment approximately 60 meters thick consisting of

diatom A diatom ( Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, diatémno, "to cut in twain". is any member of a large group comprising se ...

s and

clay mineral Clay minerals are hydrous aluminium phyllosilicates (e.g. kaolin, Al2 Si2 O5( OH)4), sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths, and other cations found on or near some planetary surfaces. Clay minera ...

s with up to 180 layers of

volcanic ash Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used to refer ...

. In Danish literature the formation has informally been referred to as the ''moler'' (''Ler'' means clay). The diatomite comprises 2/3 opal tests of diatoms and 1/3 clay, interbedded with layers of volcanic ash and a few

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms w ...

horizons (‘cementstones’), and has exceptionally complete fossil preservation. It is known for its abundant

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

fish, insects, reptiles, birds and plants. The Fur Formation was deposited just above the

Palaeocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pala ...

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', ...

boundary, about 55 million years ago, and its tropical or sub-tropical flora indicate that the climate after the Paleocene-Eocene Thermal Maximum was moderately warm (approximately 4-8 degrees warmer than today).

Glacial A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betwe ...

activity has moved and folded all exposed ''moler'' in a complicated pattern which permits very precise mapping of glacial movement at the end of the last ice age, and has, due to the ash layers, created an extraordinary pedagogical case for studying

tectonics Tectonics (; ) are the processes that control the structure and properties of the Earth's crust and its evolution through time. These include the processes of mountain building, the growth and behavior of the strong, old cores of continents k ...

Members

The Fur Formation is divided into two members: The lower Knudeklint Member was named for a location on the island of Fur. The upper Silstrup Member was named for a location in Thy. The stratigraphy exposed at Knudeklint constitutes the unit that containing the

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pala ...

boundary informally named Stolleklint Clay, which grades up into the Fur Formation.

Paleontological significance

Fossils of great diversity and unique preservation (only 10 my. after the ‘great extinction’ of dinosaurs, ammonites etc.) Most unusual, if not unique, diversity of life from both ocean and land with extremely good preservation of details rarely seen, therefore very reliable reconstruction of palaeobiology. By far most of the important ‘Danekræ’ fossils since 1990 have been found in the ‘Mo-clay area’.Bonde, N., Andersen, S., Hals, N., and Jakobsen, S.T. (2008). ''Danekræ - Danmarks bedste fossiler.'' Copenhagen: Gyldendal. 224 pp.

Birds

The earliest

Paleogene The Paleogene ( ; also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago ( Mya) to the beginning o ...

fauna of any diversity, over 30 species, including some near complete, some preserved in 3-D, and some excellent bird-fossils (even with

feathers Feathers are epidermal growths that form a distinctive outer covering, or plumage, on both avian (bird) and some non-avian dinosaurs and other archosaurs. They are the most complex integumentary structures found in vertebrates and a premier ...

and

chromatine Chromatin is a complex of DNA and protein found in eukaryote, eukaryotic cells. The primary function is to package long DNA molecules into more compact, denser structures. This prevents the strands from becoming tangled and also plays important ...

). Most are earliest known representatives of their

orders Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

(e.g.

Trogons The trogons and quetzals are birds in the order Trogoniformes which contains only one family, the Trogonidae. The family Trogonidae contains 46 species in seven genera. The fossil record of the trogons dates back 49 million years to the Early E ...

Swifts Swift or SWIFT most commonly refers to: * SWIFT, an international organization facilitating transactions between banks ** SWIFT code * Swift (programming language) * Swift (bird), a family of birds It may also refer to: Organizations * SWIFT, a ...

, Ibises) and all are terrestrial birds.Pedersen, G. K., Pedersen, S. A. S., Bonde, N., Heilmann-Clausen, C., Larsen, L. M., Lindow, B., Madsen, H., Pedersen, A. K., Rust, J., Schultz, B. P., Storey, M. og Willumsen, P. S. 2012: Molerområdets geologi – sedimenter, fossiler, askelag og glacialtektonik. Geologisk Tidsskrift 2011, pp. 41–135

/ref> * †

Lithornithiformes Lithornithidae is an extinct, possibly paraphyletic (but see below) group of early paleognath birds. They are known from fossils dating to the Upper Paleocene through the Middle Eocene of North America and Europe, with possible Late Cretaceou ...

Galliformes Galliformes is an order of heavy-bodied ground-feeding birds that includes turkeys, chickens, quail, and other landfowl. Gallinaceous birds, as they are called, are important in their ecosystems as seed dispersers and predators, and are ofte ...

* Gruiformes :*

Rallidae The rails, or Rallidae, are a large cosmopolitan family of small- to medium-sized, ground-living birds. The family exhibits considerable diversity and includes the crakes, coots, and gallinules. Many species are associated with wetlands, alth ...

:* † Messelornithidae * Apodiformes (Swifts) *

Charadriiformes Charadriiformes (, from ''Charadrius'', the type genus of family Charadriidae) is a diverse order of small to medium-large birds. It includes about 390 species and has members in all parts of the world. Most charadriiform birds live near water a ...

* Psittaciformes * Musophagiformes * Coliiformes * Strigiformes *

Caprimulgiformes Nightjars are medium-sized nocturnal or crepuscular birds in the family Caprimulgidae and order Caprimulgiformes, characterised by long wings, short legs, and very short bills. They are sometimes called goatsuckers, due to the ancient folk tal ...

Coraciiformes The Coraciiformes are a group of usually colourful birds including the kingfishers, the bee-eaters, the rollers, the motmots, and the todies. They generally have syndactyly, with three forward-pointing toes (and toes 3 & 4 fused at their bas ...

* Trogoniformes :* Primoscenidae :* Trogonidae ::*†'' Septentrogon madseni'' File:Septencoracias morsensis block.jpg, '' Septencoracias morsensis'' File:Bird_skeleton_December_019.jpg, Bird skeleton at

Fur Museum The Fur Museum is a nationally recognized local natural history museum in Denmark. The museum is named after the Danish island Fur on which it is located. When the museum was founded in 1954, the focus was on the local history of the island. In 19 ...

File:Charadriiformes-fossil.JPG, Bird (

) File:Bird-head.jpg, Bird head with preserved feathers, Geological Museum, Copenhagen

Reptiles

Several fossil sea turtles are known from the Fur Formation. In one of them, a large leatherback turtle ( Eosphargis breineri)NIELSEN, E. 1963. On the postcranial skeleton of Eosphargis breineri Nielsen. Meddelelser fra Dansk Geologisk Forening, 15, 281–328 remains of soft tissue and skin pigmentation have been recovered A number of well-preserved turtle specimens have been recovered from the Fur Formation, two of which have been recognized to be a completely new species of the genus Tasbacka Sea snakes are also known from the Fur Formation.HOCH, E. 1975. Amniote remnants from the eastern part of the Lower Eocene North Sea Basin. Colloque International du Centre National de la Recherche Scientifique, Paris, 218, 543–562.Kristensen, H.V., Cuny, G., Rasmussen, A.R., ang Madsen, H., 2012: Earliest record of the fossil snake Palaeophis from the Paleocene/Eocene boundary in Denmark. Bull. Soc. géol. France, 2012, t. 183, no 6, p. 623-627 File:Eosphargis.jpg, Leatherback turtle ''

Eosphargis breineri ''Eosphargis'' is an extinct genus of sea turtles from the Eocene of Africa, Europe, and North America. It was first named by Richard Lydekker in 1889, and contains one species, ''E. gigas''. The species is also known as ''Anglocetus beatso ...

'' skull cast, at Geological Museum in Copenhagen. File:Tasbacka danica.JPG, Sea turtle '' Tasbacka danica'' Complete unique fossil baby sea turtle. Length 10.5 cm File:Snake-Fur_Museum2162.JPG, Sea snake '' Palaeophis sp.'' in Early Eocene Stolleklint Clay, Fur Formation * '' Palaeophis'' (Sea Snake) * '' Eosphargis''brenieri (Leatherback turtle) ) * ''

Cheloniidae Cheloniidae is a family of typically large marine turtles that are characterised by their common traits such as, having a flat streamlined wide and rounded shell and almost paddle-like flippers for their forelimbs. They are the only sea turtles t ...

'' :* †''

Puppigerus ''Puppigerus'' is an extinct genus of sea turtle from the Eocene. It is known from finds in the United States, the United Kingdom, Belgium, Denmark, and Uzbekistan. Taxonomy ''Puppigerus'' was described by Edward Drinker Cope in 1870. As of ...

'' * '' Glarichelys''

Fish

Large teleostean fauna, oceanic, possibly including earliest truly deep water fish, a ‘whale-fish’; earliest members of many living families and Tertiary diversity preserved as complete skeletons; some rare and sensational large and complete specimens (two ‘bony tongues’, one tarpon. Image:Argentinoid.jpg, The most common species of fish in the Fur Formation. Image:Antigonia.jpg, ''Antigonia''- Small Eocene fish from the Fur Formation, Denmark. Image:Polymixiid.JPG, Polymixiid - Early Eocene fish from the Fur Formation, Denmark. Image:Havaborre.jpg, Unidentified fish from the Fur Formation at Fur Museum, Denmark File:Palaeocentrotus.jpg, Palaeocentrotus *'' Archaeozeus'' *'' Protozeus''

Insects

Huge fauna from land, over 200 species, many are oldest of their families; many with colour spots and eye lenses, some extraordinary preservation with stridulation (sound) apparatus in grasshoppers, and apparently migratory moth mass mortality. Species described include: *'' Cimbrophlebia bittaciformis'' - a Cimbrophlebiid scorpionfly *'' Limfjordia breineri'' - A dictyopharid plant hopper *'' Forficula paleocaenica'' - a forficulid earwig *'' Ypresiomyrma rebekkae'' - a bull dog ant File:Forficula paleocaenica Fur Formation.jpg, '' Forficula paleocaenica'' earwig Image:Cimbrophlebia bittaciformis Fur Formation.jpg, '' Cimbrophlebia bittaciformis'' (

Mecoptera Mecoptera (from the Greek: ''mecos'' = "long", ''ptera'' = "wings") is an order of insects in the superorder Endopterygota with about six hundred species in nine families worldwide. Mecopterans are sometimes called scorpionflies after their lar ...

) Fur Museum, Denmark File:Fossil_Hemiptera.JPG,

Hemiptera Hemiptera (; ) is an order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from to arou ...

(

Pentatomidae Pentatomidae is a family of insects belonging to the order Hemiptera, generally called shield bugs or stink bugs. Pentatomidae is the largest family in the superfamily Pentatomoidea, and contains around 900 genera and over 4700 species.Robert ...

) File:Parasitic-wasp.JPG, Parasitic wasp File:Ypresiomyrma rebekkae holotype.jpg, '' Ypresiomyrma rebekkae'' holotype, in Stolleklint Clay File:FUM-3-diptera.jpg,

Mosquito Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin ''culex'' meaning " gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish for "li ...

(diptera) File:FUM-4-diptera.JPG, Mosquito (diptera) File:FUM-5-Neuroptera.jpg,

Lacewing The insect order Neuroptera, or net-winged insects, includes the lacewings, mantidflies, antlions, and their relatives. The order consists of some 6,000 species. Neuroptera can be grouped together with the Megaloptera and Raphidioptera in the ...

(

Neuroptera The insect order Neuroptera, or net-winged insects, includes the lacewings, mantidflies, antlions, and their relatives. The order consists of some 6,000 species. Neuroptera can be grouped together with the Megaloptera and Raphidioptera in th ...

) File:Lacewing - Palaeopsychops latifasciatus.jpg,

Palaeopsychops ''Palaeopsychops'' is an extinct genus of lacewing in the moth lacewings family Ithonidae. The genus is known from Early Eocene fossils found in Europe, and North America and is composed of ten species. The ten species can be informally separate ...

latifasciatus

Crustacea

Extraordinary cirripeds (

barnacles A barnacle is a type of arthropod constituting the subclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosiv ...

), and the only fossil shrimps from Denmark. File:DK49_Reje.jpg, Shrimp '' Penaeus hamleti'', Stolleklint Clay File:Fossil_crab.jpg, Crab '' Portofuria enigmatica'',Stolleklint Clay File:Schrimp-Fur_Museum2060.JPG, Shrimp '' Morscrangon acutus''

Molluscs

* '' Gari'' sp. * '' Mytilus'' sp. * '' Nucula'' sp. File:Musseel.jpg, Mussel at Geological Museum in Copenhagen

Land plants

Some members of the ‘Arcto-Tertiary flora’; some with cuticle preservation and some flowers preserved. Large silicified trunks (up to 9 m) of redwood, and some very soft wood preserved. Some trunks with mussels and barnacles attached. Many seeds and fruits. File:Leaf_from_ash.jpg, Undidentified leaf File:Fossil_Leaf.JPG, Unidentified leaf file:DK502.jpg, ''Jenkinsella'' sp. seeds File:Flower-Fur_Museum1687.JPG, unidentified flower.

Diatoms

Great diversity of unicellular, marine algae with siliceous (opal) tests, 130 species.

Ash layers

More than 200 layers of

of predominantly

basalt Basalt (; ) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90 ...

ic composition have been found within the Mo-clay of the Fur Formation. 179 of the most prominent ash layers have been numbered. Comparison with volcanic ash layers in

oil well An oil well is a drillhole boring in Earth that is designed to bring petroleum oil hydrocarbons to the surface. Usually some natural gas is released as associated petroleum gas along with the oil. A well that is designed to produce only gas ma ...

s in the

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian ...

indicates that the Mo-clay is coeval with the Sele Formation and Balder Formation in the North Sea. The ash layers have also been found at other sites in

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...

Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...

and the

Bay of Biscay The Bay of Biscay (), known in Spain as the Gulf of Biscay ( es, Golfo de Vizcaya, eu, Bizkaiko Golkoa), and in France and some border regions as the Gulf of Gascony (french: Golfe de Gascogne, oc, Golf de Gasconha, br, Pleg-mor Gwaskogn), ...

. The total eruption volume of this series have been calculated as 21,000 km³, which occurred in 600,000 years. The most powerful single eruption of this series took place 54.0 million years ago (Ma) and ejected ca. 1,200 km³ of ash material, which makes it one of the largest basaltic pyroclastic eruptions in geological history. Egger, H. and Brückl, E., 2006: Gigantic volcanic eruptions and climatic change in the early Eocene - International Journal of Earth Sciences, Volume 95, Number 6, 1065-1070. Image:Fur geological layers.jpg, Image showing the distinct geological layers. Image:Fur layers 2.jpg, An inland location. Image:Fur cliffs.jpg, These cliffs of Fur have been a rich source of fossils. image:Moclay_Fur_Island_2010-08-06_2.JPG, MoClay with layers of volcanic ash

References

External links

{{Commons category, position=left Fur Formation Fossil parks Paleontology in Denmark