Volcanic plug

A volcanic plug, also called a volcanic neck or lava neck, is a volcanic object created when magma hardens within a vent on an active volcano. When present, a plug can cause an extreme build-up of pressure if rising volatile-charged magma is trapped beneath it, and this can sometimes lead to an explosive eruption. Glacial erosion can lead to exposure of the plug on one side, while a long slope of material remains on the opposite side. Such landforms are called crag and tail. If a plug is preserved, erosion may remove the surrounding rock while the erosion-resistant plug remains, producing a distinctive upstanding landform.

An example of two volcanic plugs can be found at the Pitons, in Saint Lucia, as they rise abruptly out of the eastern Caribbean Sea.

Near the village of Rhumsiki in the Far North Province of Cameroon, Kapsiki Peak is an example of a volcanic plug and is one of the most photographed parts of the Mandara Mountains. Spectacular volcanic plugs are present in the center of La Gomera island in the Canary Islands archipelago, within the Garajonay National Park.

There are several volcanic plugs in New Zealand, including the Pinnacles in the Coromandel Peninsula, Bream Head, Paritutu and the adjacent Sugar Loaf Islands, St. Paul's Rock at Whangaroa Harbour, and Piha's Lion Rock, which hosted a fortified Maori pa.

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