Garnedd-Wen Formation facts for kids
Quick facts for kids Garnedd-Wen FormationStratigraphic range: Hirnantian Age |
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The upper slopes of Tarren y Gesail are primarily in the Garnedd-Wen Formation
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| Type | Group |
| Unit of | Abercorris Group |
| Overlies | Narrow Vein Mudstone Formation |
| Thickness | 1,000 metres (3,300 ft) to 3,000 metres (9,800 ft) |
| Lithology | |
| Primary | Mudstone |
| Other | Sandstone |
| Location | |
| Coordinates | 52°38′07″N 3°54′26″W / 52.6354°N 3.9071°W |
| Region | Mid Wales |
| Country | Wales |
| Extent | Tywyn to Dinas Mawddwy |
| Type section | |
| Named for | Garneddwen |
The Garnedd-Wen Formation is a special group of rocks found in Mid Wales. Geologists also call it the Garnedd-Wen Beds. This rock formation was created during the Ordovician Period, a very long time ago. It's made up of different kinds of rocks, like mudstones, siltstones, and various types of sandstones. You can find these rocks stretching from Dinas Mawddwy in the north-east all the way to Tywyn in the south-west.
What is the Garnedd-Wen Formation?
The Garnedd-Wen Formation is a "lithostratigraphic group." This is a fancy way of saying it's a specific set of rock layers that share similar features. These layers were formed in the same geological period. The rocks in this formation include fine and coarse-grained sandstones. You can also find greywackes and conglomerates here. Greywacke is a type of sandstone that contains a mix of different rock fragments. Conglomerates are rocks made of rounded pebbles and stones cemented together.
Where can you find the Garnedd-Wen Formation?
This rock formation makes up the upper layers of rock in a large area of western Mid Wales. It's especially noticeable in the Tarren Hills. These hills are located on the south side of the Bala Fault, which is a major crack in the Earth's crust. The formation is found west of Talyllyn Lake, a beautiful lake in the region. The rocks here tell us a lot about what the Earth was like millions of years ago.
