Plattenkalk

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Plattenkalk
Solnhofen Plattenkalk (11232573043).jpg
Plattenkalk at Solnhofen
Composition
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] Lithographic limestone is a type of plattenkalk chosen for its suitable lithography characteristics.

Related Research Articles

Solnhofen Limestone

The Solnhofen Plattenkalk, or Solnhofen Limestone, geologically 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.

Phosphorite Sedimentary rock containing large amounts of phosphate minerals

Phosphorite, phosphate rock or rock phosphate is a non-detrital sedimentary rock that contains high amounts of phosphate minerals. The phosphate content of phosphorite (or grade of phosphate rock) varies greatly, from 4% to 20% phosphorus pentoxide (P2O5). Marketed phosphate rock is enriched ("beneficiated") to at least 28%, often more than 30% P2O5. This occurs through washing, screening, de-liming, magnetic separation or flotation. By comparison, the average phosphorus content of sedimentary rocks is less than 0.2%. The phosphate is present as fluorapatite Ca5(PO4)3F typically in cryptocrystalline masses (grain sizes < 1 μm) referred to as collophane-sedimentary apatite deposits of uncertain origin. It is also present as hydroxyapatite Ca5(PO4)3OH or Ca10(PO4)6(OH)2, which is often dissolved from vertebrate bones and teeth, whereas fluorapatite can originate from hydrothermal veins. Other sources also include chemically dissolved phosphate minerals from igneous and metamorphic rocks. Phosphorite deposits often occur in extensive layers, which cumulatively cover tens of thousands of square kilometres of the Earth's crust.

Bioturbation Reworking of soils and sediments by organisms.

Bioturbation is defined as the reworking of soils and sediments by animals or plants. These include burrowing, ingestion, and defecation of sediment grains. Bioturbating activities have a profound effect on the environment and are thought to be a primary driver of biodiversity. The formal study of bioturbation began in the 1800s by Charles Darwin experimenting in his garden. The disruption of aquatic sediments and terrestrial soils through bioturbating activities provides significant ecosystem services. These include the alteration of nutrients in aquatic sediment and overlying water, shelter to other species in the form of burrows in terrestrial and water ecosystems, and soil production on land.

Bear Gulch Limestone

The Bear Gulch Limestone is a limestone-rich geological lens in central Montana, renowned for the quality of its late Mississippian-aged fossils. It is exposed over a number of outcrops northeast of the Big Snowy Mountains, and is often considered a component of the more widespread Heath Formation. The Bear Gulch Limestone reconstructs a diverse, though isolated, marine ecosystem which developed near the end of the Serpukhovian age. It is a lagerstätte, a particular type of rock unit with exceptional fossil preservation of both articulated skeletons and soft tissues. Bear Gulch fossils include a variety of fish, invertebrates, and algae occupying a number of different habitats within a preserved shallow bay.

Biostratinomy Study of post-mortem–pre-burial tissue decay

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:

<i>Zoophycos</i> Trace fossil

Zoophycos is a somewhat cosmopolitan ichnogenus thought to be produced by moving and feeding polychaete worms.

<i>Trachyteuthis</i> Genus of fossil cephalopod

Trachyteuthis is a genus of fossil cephalopod, comprising five species: T. hastiformis, T. latipinnis, T. nusplingensis, T. teudopsiformis, T. covacevichi and T. chilensis.

<i>Falcatus</i> Extinct genus of cartilaginous fishes

Falcatus is an extinct genus of falcatid chondrichthyan which lived during the early Carboniferous Period in Bear Gulch bay in what is now Montana.

The Burgess Shale of British Columbia is famous for its exceptional preservation of mid-Cambrian organisms. Around 69 other sites have been discovered of a similar age, with soft tissues preserved in a similar, though not identical, fashion. Additional sites with a similar form of preservation are known from the Ediacaran and Ordovician periods.

Lithographic limestone Type of limestone with hard fine grain

Lithographic limestone is hard limestone that is sufficiently fine-grained, homogeneous and defect free to be used for lithography.

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

Fossiliferous limestone is any type of limestone, made mostly of calcium carbonate (CaCO3) in the form of the minerals calcite or aragonite, that contains an abundance of fossils or fossil traces. The fossils in these rocks may be of macroscopic or microscopic size. The sort of macroscopic fossils often include crinoid stems, brachiopods, gastropods, and other hard shelled mollusk remains.

<i>Cancrinos</i> Extinct genus of crustaceans

Cancrinos is a genus of fossil crustacean closely allied with the slipper lobsters. One species is known, C. claviger from the Jurassic of southern Germany.

Stenophlebiidae Extinct family of insects

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 Sierra Madre Formation is a geologic formation in Chiapas state, southern Mexico. It consists of marine dolomites and limestones. The formation dates to the Middle Cretaceous, spanning from the Aptian of the Early to the Cenomanian of the Late Cretaceous.

Nusplingen Limestone

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.

<i>Mauriciosaurus</i> Extinct genus of reptiles

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.

<i>Eichstaettisaurus</i> Genus of lizard from the Late Jurassic and Early Cretaceous periods

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.

References

  1. Bottjer, Etter, Hagadorn, Tang (2001). Exceptional Fossil Preservation. Columbia University Press.{{cite book}}: CS1 maint: multiple names: authors list (link)
  2. Wilkin, J.T.R. (2020) The south German Plattenkalks. Geology Today 36(1): 27-32. https://doi.org/10.1111/gto.12288