The Maidens () or Hulin Rocks () are two islets and several

skerries A skerry is a small rocky island, usually defined to be too small for habitation. Skerry, skerries, or The Skerries may also refer to: Geography Northern Ireland * Skerries, County Armagh, a townland in County Armagh * Skerry, County Antrim, a ...

in the

North Channel North Channel may refer to: *North Channel (Great Britain and Ireland) *North Channel (Ontario), body of water along the north shore of Lake Huron, Canada *North Channel, Hong Kong *Canal du Nord, France {{geodis ...

off County Antrim in Northern Ireland. The Eastern Maiden or Southern Rock lies about 9 km from the coast at

Ballygalley Ballygally or Ballygalley (, IPA: �bˠalʲəˈɟɛhlʲiː is a village and holiday resort in County Antrim, Northern Ireland which lies on the Antrim coast, approximately north of Larne. It is also a townland of and is situated in the civil p ...

, or 13 miles from Larne. The West Maiden or Northern Rock is about half a mile further out. Lighthouses were built on both rocks; the West Maiden was abandoned in 1903 and the East Maiden was automated in 1977.

Geology

The Maidens is an example of an olivine- dolerite

sill Sill may refer to: * Sill (dock), a weir at the low water mark retaining water within a dock * Sill (geology), a subhorizontal sheet intrusion of molten or solidified magma * Sill (geostatistics) * Sill (river), a river in Austria * Sill plate, a ...

, one of many similar

intrusion In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and com ...

s along the Antrim coast. They were formed during the

Paleogene The Paleogene ( ; British English, also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period, geologic period and system that spans 43 million years from the end of the Cretaceous Period million yea ...

and

Neogene The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...

periods (66 million to 2.6 million years ago), a period of intense volcanic activity in Northern Ireland. The Giant's Causeway, also from this time period, was created by volcanic eruption. At the Maidens, magma was forced underground through layers of weakness, but never reached the surface. It cooled more slowly, solidifying and leaving a hard rock, relatively resistant to weathering compared to the strata around it and so forming the islands left today. Other examples of nearby sills are Fair Head, the Portrush sill which forms Ramore Head and the Skerries, and the Knocksoghey Sill near Ballintoy, part of which forms Sheep Island.

References

{{DEFAULTSORT:Maidens Islands of County Antrim Geology of Northern Ireland Sills (geology)

Geology

See also

References