Here's why:
* Basaltic lava is very fluid due to its low silica content, allowing it to flow easily and spread over large areas.
* Shield volcanoes are characterized by their broad, gently sloping shape. This shape is a direct result of the repeated eruptions of fluid basaltic lava, which flows outwards in all directions, gradually building up the volcano.
Some examples of shield volcanoes include:
* Mauna Loa (Hawaii)
* Kilauea (Hawaii)
* Mount Etna (Italy)
* Olympus Mons (Mars)