Cinder cone by linzhengnd


									Cinder cone
From Wikipedia, the free encyclopedia
Jump to: navigation, search
For peaks named "Cinder Cone", see list of peaks named Cinder Cone.

Schematic representation of the internal structure of a typical cinder cone.

A cinder cone or scoria cone is a steep conical hill of volcanic fragments that accumulate
around and downwind from a volcanic vent.[1] The rock fragments, often called cinders or scoria,
are glassy and contain numerous gas bubbles "frozen" into place as magma exploded into the air
and then cooled quickly.[1] Cinder cones range in size from tens to hundreds of meters tall.[1]
Cinder cones are made of pyroclastic material.

Cinders from a Pleistocene cinder cone, San Bernardino Valley, southeastern Arizona.

Many cinder cones have a bowl-shaped crater at the summit. Lava flows are usually erupted by
cinder cones, either through a breach on one side of the crater or from a vent located on a
flank.[1] If the crater is fully breached, the remaining walls form an amphitheatre or horseshoe
shape around the vent. Lava rarely issues from the top (except as a fountain) because the loose,
uncemented cinders are too weak to support the pressure exerted by molten rock as it rises
toward the surface through the central vent.[1]
Capulin Volcano cinder cone, New Mexico.

Cinder cones are commonly found on the flanks of shield volcanoes, stratovolcanoes, and
calderas.[1] For example, geologists have identified nearly 100 cinder cones on the flanks of
Mauna Kea, a shield volcano located on the island of Hawaii.[1] These cones are also referred to
as 'scoria cones' and 'cinder and spatter cones.'[1]

Perhaps the most famous cinder cone, Paricutin, grew out of a corn field in Mexico in 1943 from
a new vent.[1] Eruptions continued for 9 years, built the cone to a height of 424 meters, and
produced lava flows that covered 25 km².[1]

The Earth's most historically active cinder cone is Cerro Negro in Nicaragua.[1] It is part of a
group of four young cinder cones NW of Las Pilas volcano.[1] Since it was born in 1850, it has
erupted more than 20 times, most recently in 1992 and 1995.[1]

    1. ^ a b c d e f g h i j k l m This article incorporates public domain material from the United States
       Geological Survey document "Photo glossary of volcano terms: Cinder cone".

  A cinder cone is a steep conical hill formed above a vent. Cinder cones are among the most common
volcanic landforms found in the world. They aren't famous as their eruptions usually don't cause any loss
of life. Cinder cones are chiefly formed by Strombolian eruptions. The cones usually grow up in groups
and they often occur on the flanks of strato volcanoes and shield volcanoes.

   Cinder cones are built from lava fragments called cinders. The lava fragments are ejected from a
single vent and accumulate around the vent when they fall back to earth.

   Cinder cones grow rapidly and soon approach their maximum size. They rarely exceed 250m in
height and 500m in diameter.
                                         (Fig.2.7) Cinder Cone.

    The shape of a cinder cone can be modified during its (short) life. When the position of the vent
alters, aligned, twin or secant cones develop. Nested,buried or breached cones are formed when the
power of the eruption varies.

    A great example of a cinder cone is Paricutín in Mexico. It was born in February 20, 1943 in a corn
field and grew to 300 feet in 5 days.

Cinder Cones
Cinder cones are simple volcanoes which have a bowl-shaped crater at the summit and only
grow to about a thousand feet, the size of a hill. They usually are created of eruptions from a
single opening, unlike a strato-volcano or shield volcano which can erupt from many different

They are usually made of piles of lava, not ash. During the eruption, blobs ("cinders") of lava,
blown into the air, break into small fragments that fall around the opening to the volcano. The
pile forms an oval-shaped small volcano, as shown in this picture.

Famous cinder cones include Paricutin in Mexico. Another well known cinder cone is in the
middle of Crater Lake.

To top