The Aymestry Limestone is a

fossiliferous limestone Fossiliferous limestone is a type of limestone that contains noticeable quantities of fossils or trace fossil, fossil traces. If a particular type of fossil dominates, a more specialized term can be used as in "Ames Limestone, Crinoidal", "Coral ...

Gorstian In the geologic timescale, the Gorstian is an age of the Ludlow Epoch of the Silurian Period of the Paleozoic Era of the Phanerozoic Eon that is comprehended between 427.4 ± 0.5 Ma and 425.6 ± 0.9 Ma (million years ago), approximately. The ...

age (

Upper Silurian The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the third and shortest period of t ...

) deposited in a warm shallow sea near the eastern margin of the

Iapetus Ocean The Iapetus Ocean (; ) existed in the late Neoproterozoic and early Paleozoic eras of the geologic timescale (between 600 and 400 million years ago). It was in the southern hemisphere, between the paleocontinents of Laurentia, Baltica and Avalon ...

. It occurs in

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

in the

Ludlow Group The Ludlow Group are geologic formations deposited during the Ludlow epoch of the Silurian period in the British Isles, in areas of England, Ireland, Scotland, and Wales. Formations This group contains the following formations in descending or ...

, between the Upper and Lower Ludlow Shales. It derives its name from

Aymestrey Aymestrey ( ) is a village and civil parish in north-western Herefordshire, England. The population of this civil parish, including the hamlet of Yatton, Aymestrey, Yatton, at the United Kingdom Census 2011, 2011 Census was 351. Location It ...

(sic),

Herefordshire Herefordshire ( ) is a Ceremonial counties of England, ceremonial county in the West Midlands (region), West Midlands of England, bordered by Shropshire to the north, Worcestershire to the east, Gloucestershire to the south-east, and the Welsh ...

, where it may be seen on both sides of the

River Lugg The River Lugg () rises near Llangynllo in Powys, Wales. From its source, it flows through the border town of Presteigne and then into Herefordshire, England. It meets its main tributary, the River Arrow, to the south of Leominster, then ...

. It is well developed in the neighbourhood of

Ludlow Ludlow ( ) is a market town and civil parish in Shropshire (district), Shropshire, England. It is located south of Shrewsbury and north of Hereford, on the A49 road (Great Britain), A49 road which bypasses the town. The town is near the conf ...

(it is sometimes called the Ludlow limestone) and occupies a similar position in the Ludlow shales at

Woolhope Woolhope is a village and civil parish in the English county of Herefordshire. The population of the civil parish was 486 at the 2011 census. The civil parish includes the hamlet of Broadmoor Common to the west of the village (and a nature res ...

, the

Abberley Hills Abberley is a village and Civil parishes in England, civil parish in north west Worcestershire, England. It is situated on the northern slopes of Abberley Hill, which is tall, between the River Severn and River Teme. The civil parish had a p ...

, May Hill and the

Malvern Hills The Malvern Hills are in the English counties of Worcestershire, Herefordshire and a small area of northern Gloucestershire, dominating the surrounding countryside and the towns and villages of the district of Malvern. The highest summit af ...

Description

In lithological character, this limestone varies greatly; in one place it is a dark grey, somewhat crystalline limestone, elsewhere it passes into a flaggy, earthy or shaly condition, or even into a mere layer of nodules. When well developed it may reach 50 ft. in thickness in beds of from 1 to 5 ft.; in this condition it naturally forms a conspicuous feature in the landscape because it stands out by its superior hardness from the soft

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...

s above and below. The most common

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 preserve ...

is '' Pentamerus knightii'', which is extremely abundant in places. Other

brachiopod Brachiopods (), phylum (biology), phylum Brachiopoda, are a phylum of animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear e ...

coral Corals are colonial marine invertebrates within the subphylum Anthozoa of the phylum Cnidaria. They typically form compact Colony (biology), colonies of many identical individual polyp (zoology), polyps. Coral species include the important Coral ...

s and

trilobite Trilobites (; meaning "three-lobed entities") are extinction, extinct marine arthropods that form the class (biology), class Trilobita. One of the earliest groups of arthropods to appear in the fossil record, trilobites were among the most succ ...

s are present, and are similar to those found in the Wenlock limestone.

References

External links

* * Geologic formations of England Silurian England Silurian southern paleotemperate deposits Limestone formations of the United Kingdom Mudstone formations of the United Kingdom Sandstone formations Fossiliferous stratigraphic units of Europe Paleontology in the United Kingdom {{UK-geologic-formation-stub

Description

See also

References

Further reading

External links