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Limestone |
Plattenkalk is a very finely grained limestone chemically precipitated in a stratified water column under conditions where bioturbation does not occur. The reasons for the quiet depositional environment and the processes of sediment accumulation vary greatly among different plattenkalks, but the lack of bioturbation contributes to the creation of thinly bedded, finely laminated, undisturbed limestones where exceptionally detailed fossils or imprints of organisms occur. The Solnhofen Plattenkalk in Bavaria is a famous example where complete skeletons of large marine vertebrates and impressions of soft-bodied animals have been found. [1] [2] [3] Lithographic limestone is a type of plattenkalk chosen for its suitable lithography characteristics.
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles to settle in place. The particles that form a sedimentary rock are called sediment, and may be composed of geological detritus (minerals) or biological detritus. The geological detritus originated from weathering and erosion of existing rocks, or from the solidification of molten lava blobs erupted by volcanoes. The geological detritus is transported to the place of deposition by water, wind, ice or mass movement, which are called agents of denudation. Biological detritus was formed by bodies and parts of dead aquatic organisms, as well as their fecal mass, suspended in water and slowly piling up on the floor of water bodies. Sedimentation may also occur as dissolved minerals precipitate from water solution.
The Solnhofen Limestone or Solnhofen Plattenkalk, formally known as the Altmühltal Formation, is a Jurassic Konservat-Lagerstätte that preserves a rare assemblage of fossilized organisms, including highly detailed imprints of soft bodied organisms such as sea jellies. The most familiar fossils of the Solnhofen Plattenkalk include the early feathered theropod dinosaur Archaeopteryx preserved in such detail that they are among the most famous and most beautiful fossils in the world. The Solnhofen beds lie in the German state of Bavaria (Bayern), halfway between Nuremberg (Nürnberg) and Munich (München) and were originally quarried as a source of lithographic limestone. The Jura Museum situated in Eichstätt, Germany has an extensive exhibit of Jurassic fossils from the quarries of Solnhofen and surroundings, including marine reptiles, pterosaurs, and one specimen of the early bird Archaeopteryx.
The Purbeck Group is an Upper Jurassic to Lower Cretaceous lithostratigraphic group in south-east England. The name is derived from the district known as the Isle of Purbeck in Dorset where the strata are exposed in the cliffs west of Swanage.
The Kaibab Limestone is a resistant cliff-forming, Permian geologic formation that crops out across the U.S. states of northern Arizona, southern Utah, east central Nevada and southeast California. It is also known as the Kaibab Formation in Arizona, Nevada, and Utah. The Kaibab Limestone forms the rim of the Grand Canyon. In the Big Maria Mountains, California, the Kaibab Limestone is highly metamorphosed and known as the Kaibab Marble.
The Hunsrück Slate is a Lower Devonian lithostratigraphic unit, a type of rock strata, in the German regions of the Hunsrück and Taunus. It is a lagerstätte famous for exceptional preservation of a highly diverse fossil fauna assemblage.
Biostratinomy is the study of the processes that take place after an organism dies but before its final burial. It is considered to be a subsection of the science of taphonomy, along with necrology and diagenesis. These processes are largely destructive, and include physical, chemical and biological effects:
The Blue Lias is a geological formation in southern, eastern and western England and parts of South Wales, part of the Lias Group. The Blue Lias consists of a sequence of limestone and shale layers, laid down in latest Triassic and early Jurassic times, between 195 and 200 million years ago. The Blue Lias is famous for its fossils, especially ammonites.
Lithographic limestone is hard limestone that is sufficiently fine-grained, homogeneous and defect free to be used for lithography.
The Posidonia Shale geologically known as the Sachrang Formation, is an Early Jurassic geological formation of southwestern and northeast Germany, northern Switzerland, northwestern Austria, southern Luxembourg and the Netherlands, including exceptionally well-preserved complete skeletons of fossil marine fish and reptiles.
The Walcott–Rust quarry, in Herkimer County, New York, is an excellent example of an obrution Lagerstätte. Unique preservation of trilobite appendages resulted from early consolidation (cementation) of the surrounding rock, followed by spar filling of the interior cavity within the appendages. The presence of so many well preserved trilobites in one location alone qualifies the beds as an exceptional trilobite site, but the beds are further distinguished as the source of the first trilobites for which appendages were definitively described.
Fossiliferous limestone is a type of limestone that contains noticeable quantities of fossils or fossil traces. If a particular type of fossil dominates, a more specialized term can be used as in "Crinoidal", "Coralline", "Conchoidal" limestone. If seashells, shell fragments, and shell sand form a significant part of the rock, a term "shell limestone" is used.
The Muav Limestone is a Cambrian geologic formation within the 5-member Tonto Group. It is a thin-bedded, gray, medium to fine-grained, mottled dolomite; coarse- to medium-grained, grayish-white, sandy dolomite and grayish-white, mottled, fine-grained limestone. It also contains beds of shale and intraformational conglomerate. The beds of the Muav Limestone are either structureless or exhibit horizontally laminations and cross-stratification. The Muav Limestone forms cliffs or small ledges that weather a dark gray or rusty-orange color. These cliffs or small ledges directly overlie the sloping surfaces of the Bright Angel Shale. The thickness of this formation decreases eastward from 76 m (249 ft) in the western Grand Canyon to 14 m (46 ft) in the eastern Grand Canyon. To the west in southern Nevada, its thickness increases to 250 m (820 ft) in the Frenchman Mountain region.
The Stenophlebiidae is an extinct family of medium-sized to large fossil odonates from the Upper Jurassic and Cretaceous period that belongs to the damsel-dragonfly grade ("anisozygopteres") within the stem group of Anisoptera. They are characterized by their long and slender wings, and the transverse shape of the discoidal triangles in their wing venation.
The Redwall Limestone is an erosion-resistant, Mississippian age, cliff-forming geological formation that forms prominent, red-stained cliffs in the Grand Canyon. these cliffs range in height from 150 m (490 ft) to 244 m (801 ft). It is one of the most fossiliferous formations exposed in the Grand Canyon region.
The Cliefden Caves is a heritage-listed geoheritage site in Mandurama, Cowra Shire, New South Wales, Australia. The caves comprise Ordovician fossil localities, limestone caves, a spring and tufa dams, and a site where limestone was first discovered in inland Australia.
The Nusplingen Limestone is a geological formation in Baden-Württemberg, Germany. It preserves fossils dating to the Kimmeridgian age of the Late Jurassic. It mainly consists of lithographic limestones deposited in a marine basin, similar to the Solnhofen Limestone. Fossils of pterosaurs, thalattosuchians, and the oldest geophilomorph centipede Eogeophilus were found in the Nusplingen Limestone.
Mauriciosaurus is a genus of polycotylid plesiosaur from the Late Cretaceous of Mexico. It contains a single species, M. fernandezi, described in 2017 by Eberhard Frey and colleagues from a single well-preserved juvenile specimen about 1.9 metres long. Morphologically, it is overall most similar to the polycotyline polycotylids Trinacromerum and Dolichorhynchops. However, several features separate Mauriciosaurus from all other polycotylids, warranting the naming of a new genus. These include the sophisticated pattern of ridges on the bottom of the parasphenoid bone on its palate; the narrow openings in the palate bordered by the pterygoid bones; the lack of perforations in the surface of the coracoid; and the highly unusual arrangement of gastralia, or belly ribs, which is only otherwise seen in the non-polycotylid Cryptoclidus.
Eichstaettisaurus is a genus of lizards from the Late Jurassic and Early Cretaceous of Germany, Spain, and Italy. With a flattened head, forward-oriented and partially symmetrical feet, and tall claws, Eichstaettisaurus bore many adaptations to a climbing lifestyle approaching those of geckoes. The type species, E. schroederi, is among the oldest and most complete members of the Squamata, being known by one specimen originating from the Tithonian-aged Solnhofen Limestone of Germany. A second species, E. gouldi, was described from another skeleton found in the Matese Mountains of Italy. Despite being very similar to E. schroederi, it lived much later, during the Albian stage. Fossils of both species show exceptional preservation due to deposition in low-oxygen marine environments.
The geology of Greece is highly structurally complex due to its position at the junction between the European and African tectonic plates.
The Granton Shrimp Bed is a fossil-bearing deposit exposed on the southern shore of the Firth of Forth near Edinburgh, in Scotland. It is classified as a Konservat-Lagerstätten because of the exceptional quality of preservation of the fossils and is dominated by crustaceans; the deposit dates back to the Lower Carboniferous, some 359 to 323 million years ago.
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