A volcanic neck, also known as a volcanic conduit, is the solidified remains of magma that once flowed through a volcanic vent. Over time, as the surrounding softer material erodes due to various geological processes such as wind and water erosion, the more resistant rock that makes up the volcanic neck is left standing prominently above the surrounding landscape.
The distinct feature of a volcanic neck is its origin; it forms when magma is trapped in a volcanic pipe and cools and solidifies. Once the softer volcanic materials and ash have eroded away, what remains is the shape of the pipe, which can take on various forms but is generally a steep-sided column. The visibility of these structures provides valuable information about the volcanic activity that once occurred in the area.
In contrast, a lava flow refers to the movement of molten rock during an eruption, a crater is the depression or hole that forms at the summit of a volcano after an eruption, and a pipe refers generally to a channel through which magma travels to the surface, which is similar to a volcanic neck but not solidified. Therefore, identifying a volcanic neck specifically points to both its formation and the geological processes that result in its prominent elevation above the surrounding terrain.