Shield Volcanoes
Shield volcanoes, as the name states are like shields, they are very broad, wide and flat. These kinds of volcano occur at constructive plate boundaries. Shield volcanoes are normally made when two plates move apart (constructive plates) form a gap which is then filled with magma from inside the earth which then forms a shield volcano. Another way a shield volcano is formed is when it goes under a hotspot which causes an island to form. The hotspot is very hot and spews out lava which then dries when it cools. The lava will keep coming out until it forms a volcano or island (The Hawaiin islands are made this way). The hotspot will then send lava to the volcano which them makes the erupt.

Shield volcanoes have runny lava which can flow far away from the volcano. This also makes the volcano sides really smooth and gentle. These volcanoes don't erupt violently as the lava is runny.shield_volcanoes.jpg
Mt Bellknap Oregon
A shield volcano that is in the US