The Kimmeridge Clay is a
sedimentary
Sedimentary rocks are types of rock (geology), rock that are formed by the accumulation or deposition of mineral or organic matter, organic particles at Earth#Surface, Earth's surface, followed by cementation (geology), cementation. Sedimentati ...
deposit of
fossiliferous
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 ...
marine
clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4).
Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...
which is of
Late Jurassic
The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987.
In European lithostratigraphy, the name ...
to lowermost
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
age and occurs in southern and eastern England and 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 S ...
.
This rock
formation
Formation may refer to:
Linguistics
* Back-formation, the process of creating a new lexeme by removing or affixes
* Word formation, the creation of a new word by adding affixes
Mathematics and science
* Cave formation or speleothem, a secondar ...
is the major
source rock
In petroleum geology, source rock is rock which has generated hydrocarbons or which could generate hydrocarbons. Source rocks are one of the necessary elements of a working petroleum system. They are organic-rich sediments that may have been depo ...
for
North Sea oil
North Sea oil is a mixture of hydrocarbons, comprising liquid petroleum and natural gas, produced from petroleum reservoirs beneath the North Sea.
In the petroleum industry, the term "North Sea" often includes areas such as the Norwegian Sea ...
. The fossil fauna of the Kimmeridge Clay includes turtles,
crocodile
Crocodiles (family (biology), family Crocodylidae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to inclu ...
s,
sauropods
Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their b ...
,
plesiosaurs
The Plesiosauria (; Greek: πλησίος, ''plesios'', meaning "near to" and ''sauros'', meaning "lizard") or plesiosaurs are an order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia.
Plesiosaurs first appeared i ...
,
pliosaurs and
ichthyosaurs, as well as a number of
invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...
species.
Description
Kimmeridge Clay is named after the village of
Kimmeridge
Kimmeridge () is a small village and civil parish on the Isle of Purbeck, a peninsula on the English Channel coast in Dorset, England. It is situated about south of Wareham and west of Swanage. In 2013 the estimated population of the civil p ...
on the
Dorset
Dorset ( ; archaically: Dorsetshire , ) is a county in South West England on the English Channel coast. The ceremonial county comprises the unitary authority areas of Bournemouth, Christchurch and Poole and Dorset (unitary authority), Dors ...
coast of England, where it is well exposed and forms part of the
Jurassic Coast
The Jurassic Coast is a World Heritage Site on the English Channel coast of southern England. It stretches from Exmouth in East Devon to Studland Bay in Dorset, a distance of about , and was inscribed on the World Heritage List in mid-Decembe ...
World Heritage Site
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 h ...
.
Onshore, it is of Late Jurassic (
Kimmeridgian
In the geologic timescale, the Kimmeridgian is an age in the Late Jurassic Epoch and a stage in the Upper Jurassic Series. It spans the time between 157.3 ± 1.0 Ma and 152.1 ± 0.9 Ma (million years ago). The Kimmeridgian follows the Oxfordian ...
) age and outcrops across England, in a band stretching from Dorset in the south-west, north-east to
North Yorkshire
North Yorkshire is the largest ceremonial counties of England, ceremonial county (lieutenancy area) in England, covering an area of . Around 40% of the county is covered by National parks of the United Kingdom, national parks, including most of ...
. Offshore, it extends into the Lower Cretaceous (
Berriasian
In the geological timescale, the Berriasian is an age/stage of the Early/Lower Cretaceous. It is the oldest subdivision in the entire Cretaceous. It has been taken to span the time between 145.0 ± 4.0 Ma and 139.8 ± 3.0 Ma (million years ago ...
Stage) and it is found throughout the Southern, Central and Northern North Sea.
The foundations of the
Humber Bridge on the southern (Barton) side of the bridge are on Kimmeridge Clay beneath superficial deposits, under the
Humber
The Humber is a large tidal estuary on the east coast of Northern England. It is formed at Trent Falls, Faxfleet, by the confluence of the tidal rivers Ouse and Trent. From there to the North Sea, it forms part of the boundary between t ...
estuary.
Economic importance
Kimmeridge Clay is of great economic importance,
being the major
source rock
In petroleum geology, source rock is rock which has generated hydrocarbons or which could generate hydrocarbons. Source rocks are one of the necessary elements of a working petroleum system. They are organic-rich sediments that may have been depo ...
for oil fields in the
North Sea hydrocarbon province.
It has distinctive physical properties and
log responses.
Vertebrate fauna
Fauna uncovered from the Kimmeridge Clay include:
[Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Jurassic, Europe)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 545–549. .]
Ray-finned fish
Lobe-finned fish
Cartilaginous fish
Turtles
Archosaurs
Thalattosuchians
Ornithischians
Indeterminate ankylosaur osteoderms have been found in Wiltshire, England. Indeterminate stegosaurid remains have been found in Dorset and Wiltshire, England.
Saurischians
Indeterminate ornithomimmid remains have been found in Dorset, England.
An undescribed theropod genus was found in Dorset.
Pterosaurs
Plesiosaurs
Ichthyosaurs
Invertebrates
The invertebrate fauna of the Kimmeridge Clay includes:
[http://www.fullbooks.com/The-Student-s-Elements-of-Geology7.html The Student's Elements of Geology by Sir Charles Lyell Part 7 out of 14 accessed 13 February 2009.]
*
Mollusca
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...
:
**''Cardium striatulum''
** ''Ostrea deltoidea''
**''Gryphaea'' (''Exogyra'') ''virgula''
** ''
Trigonellites''
** ''
Belemnotheutis''
**''
Etchesia''
*
Arthropoda
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...
:
**''Phlyctosoma sp.''
** ''
Eryma
''Eryma'' is a genus of fossil lobster-like crustacean
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapoda, decapods, ostracoda, seed shrimp, branchiopoda, branchiopods, argulidae, fish lice, ...
sp.''
** ''Magitalatimana sp.''
** ''Mechochirus sp.''
** ''Archaeolepas redtenbacheri''
See also
*
List of dinosaur-bearing rock formations
This list of dinosaur-bearing rock formations is a list of geologic formations in which dinosaur fossils have been documented.
Containing body fossils
* List of stratigraphic units with dinosaur body fossils
** List of stratigraphic units with ...
References
Bibliography
* Galton, P.M. 1999. Cranial anatomy of the hypsilophodontid dinosaur Bugenasaura infernalis (Ornithischia: Ornithopoda) from the Upper Cretaceous of North America. Revue Pale´obiologie, 18, 517–534.
Further reading
* Martill, D.M., Naish, D. & Earland, S. 2006. Dinosaurs in marine strata: evidence from the British Jurassic, including a review of the allochthonous vertebrate assemblage from the marine Kimmeridge Clay Formation (Upper Jurassic) of Great Britain. In: Colectivo Arqueologico y Paleontologico Salense, (ed.) Actas de las III Jornadas Intrernacionales sobre Paleontologı´a de Dinosaurios y su Entorno, 16–17 September 2004. Salas de los Infantes, Burgos, 47–84.
{{Authority control
Geologic formations of England
Jurassic System of Europe
Jurassic England
Tithonian Stage
Lower Cretaceous Series of Europe
Cretaceous England
Berriasian Stage
Shale formations
Shallow marine deposits
Source rock formations
Fossiliferous stratigraphic units of Europe
Paleontology in England
Geography of Dorset
Geology of the North Sea
Energy in Europe