Shield volcano are cave-like volcanic straights formed by the hardening of overlaying lava. These structures help further the propagation of lava, as the walls of the tube insulates the lava within. Lava tubes can account for a large portion of shield volcano activity; for example, an estimated 58% of the lava forming Kīlauea comes from lava tubes. In some shield volcano eruptions, basaltic lava pours out of a long fissure instead of a central vent, and shrouds the countryside with a long band of volcanic material in the form of a broad plateau. Plateaus of this type exist in Iceland, Washington, Oregon,
The Quill (volcano) The Quill (volcano) The Quill is a stratovolcano located on the island of Sint Eustatius in the Caribbean Netherlands. The summit elevation is above sea level. It is also the second highest mountain in the Netherlands. The name 'Quill' originates from the Dutch term "kuil" (), meaning 'pit' or 'hole', which was used originally with reference to the volcanic crater. The Quill was designated as a national park by the government of the Netherlands Antilles in 1998. It is administered by the Sint Eustatius National Parks Foundation, STENAPA, which maintains a number of trails for hikers. The Quill formed between