Dike Cutting Folded Layers
What is a Dike
A dike (or dyke) is a type of geological formation where molten rock (magma) intrudes into a fracture or crack in existing rock layers and then solidifies. Dikes are typically vertical or near-vertical sheet-like bodies of igneous rock that cut across the surrounding rock layers. They form when magma is forced upward through fractures in the Earth's crust, often as a result of tectonic activity.
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| A Dike of Cenozoic Age Cutting Folded Layers. |
In the Augrim Quarry, County Down, Northern Ireland, a striking geological feature is on display: a Cenozoic-aged dike that cuts discordantly through complexly folded wacke formations. The dike, a 2-meter-wide reddish structure, can be seen rising nearly vertically up the rock face behind a person standing in the foreground.
Formation and Significance
Dikes are common in volcanic regions, where they can invade the cone and inner core of a volcano. They often form along zones of structural weakness, such as fractures or faults, where magma can more easily penetrate. In some cases, hundreds of dikes can be found within a single volcanic system, highlighting the dynamic and intrusive nature of magmatic activity.
The dike at Augrim Quarry is a remarkable example of this geological process. Its vivid reddish hue and vertical orientation provide a clear contrast to the surrounding folded wacke, offering a visual representation of the powerful forces that shape the Earth's crust. This feature not only serves as a testament to the region's volcanic history but also provides valuable insights into the processes of magma intrusion and rock deformation.
