Prelims MCQ · Geography
Consider the following statements:
- Shield volcanoes are composed mainly of fluid basaltic lava and usually have low-explosivity eruptions.
- Composite volcanoes erupt cooler and more viscous lava than basalt and commonly accumulate layers of lava, ash and pyroclastic material.
- Calderas characteristically build tall volcanic structures rather than collapsing after explosive eruptions.
- The system of mid-ocean ridges extends for more than 70,000 km, with frequent eruptions occurring along its central portions.
Which of the statements given above are correct?