The Slyne-Erris Trough is a

geological Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other E ...

basin off the west coast of

Donegal Donegal may refer to: County Donegal, Ireland * County Donegal, a county in the Republic of Ireland, part of the province of Ulster * Donegal (town), a town in County Donegal in Ulster, Ireland * Donegal Bay, an inlet in the northwest of Ireland b ...

Ireland Ireland ( ; ga, Éire ; Ulster-Scots: ) is an island in the North Atlantic Ocean, in north-western Europe. It is separated from Great Britain to its east by the North Channel, the Irish Sea, and St George's Channel. Ireland is the s ...

. In recent years it has been shown to be prospective for

hydrocarbon In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ...

s, hosting

Royal Dutch Shell Shell plc is a British multinational oil and gas company headquartered in London, England. Shell is a public limited company with a primary listing on the London Stock Exchange (LSE) and secondary listings on Euronext Amsterdam and the New ...

Corrib gas field (discovered by

Enterprise Oil Enterprise Oil was a major UK independent exploration and production company based in Europe, with core areas of activity in the United Kingdom and Ireland, mainland Europe, Brazil and the Gulf of Mexico. The Company was once a constituent of t ...

, bought by Shell), and several other prospects being evaluated by a number of other oil companies. Structurally, the trough is a series of NNE-SSW trending

half-graben A half-graben is a geological structure bounded by a fault along one side of its boundaries, unlike a full graben where a depressed block of land is bordered by parallel faults. Rift and fault structure A rift is a region where the lithosphere ...

The Slyne Trough

The Slyne Trough or Slyne Basin consists of three sub-basins, the Northern, Central and Southern Slyne Basins. The Northern and Central Slyne Basins are half-grabens of opposite polarity with the switch occurring across the Central Slyne Transfer, interpreted to be a splay of the

Great Glen Fault The Great Glen Fault is a strike-slip fault that runs through the Great Glen in Scotland. The fault is mostly inactive today, but occasional moderate tremors have been recorded over the past 150 years. Location Aligned northeast to southwest, t ...

. The Corrib Field is situated in the Northern Slyne Basin. In the Central Slyne the 27/5-1 well proved the presence of Late

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleo ...

evaporites including salt, possibly indicating fault activity at this time. The basin is interpreted to have been active particularly during the

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest per ...

and Middle

Jurassic The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of ...

periods. The Slyne Basin links the Erris and

Porcupine Basin The Porcupine Seabight or Porcupine Basin is a deep-water oceanic basin located on the continental margin in the northeastern portion of the Atlantic Ocean. It can be found in the southwestern offshore portion of Ireland and is part of a series o ...

The Erris Trough

The Erris Trough or Erris Basin is a half-graben that runs parallel with the

Rockall Basin The Rockall Trough ( gd, Clais Sgeir Rocail) is a deep-water bathymetric feature to the northwest of Scotland and Ireland, running roughly from southwest to northeast, flanked on the north by the Rockall Plateau and to the south by the Porcupi ...

and is separated from it by a horst structure, the Erris Ridge. It is interpreted to have been active particularly during the

and middle

periods.

References

* P.N.Dancer, S.T.Algar & I.R.Wilson. 1999. Structural evolution of the Slyne Trough. In: A.J.Fleet & S.A.R.Boldy(editors) Petroleum Geology of Northwest Europe: Proceedings of the 5th Conference, 445-453. Geological Society of London. * T.J.Chapman, T.M.Broks, D.V.Corcoran, L.A.Duncan & P.N.Dancer. 1999. The structural evolution of the Erris Trough, offshore northwest Ireland, and its implications for hydrocarbon generation. In: A.J.Fleet & S.A.R.Boldy(editors) Petroleum Geology of Northwest Europe: Proceedings of the 5th Conference, 455-469. Geological Society of London. {{coord missing, Ireland Economic geology Structural geology Sedimentary basins of Europe Geography of Ireland Mesozoic rifts and grabens