CONES

Volcanic cones are among the simplest volcanic formations. They are built by ejects from a volcanic
vent, piling up around the vent in the shape of a cone with a central crater. Volcanic cones are of
different types, depending upon the nature and size of the fragments ejected during the eruption.

Shield Cones

1. - produced by the accumulation of fluid basaltic lava
2. - broad, slightly dome structure or a gently sloping mountain
3. - usually has gentle eruptions and quiet lava that covers a large area
4. - Ex. Taal Volcano; Mauna Kea in Hawaii

Cinder Cones

1. - a small volcano built primarily of pyroclastic materials ejected from a single vent formed from explosive eruptions
2. - active for only a short time
3. - has a narrow base and steep sides; not very high
4. - erodes easily
5. - Ex. Jolo volcano

Composite Cones

1. - �stratovolcano�
2. - often develop into high volcanic-mountains
3. - built up of alternating layers of rock particles and lava
4. - formed by alternating and repeated violent and quiet eruptions
5. - Ex. Mayon Volcano (Albay), Bulusan Volcano, Mount St. Helens (Washington)

Active volcano

� currently in a state of regular eruptions and expected to erupt again very soon;
had an eruption within the last 10,000 years or so.

Dormant volcano

� one capable of erupting, and will probably erupt in the future,
but it had no eruption for a very long time.

Extinct volcano

� never had an eruption before and is not expected to erupt in the future.