Types of Volcano

1. Shield Volcanoes These are the largest of all volcanoes on Earth (excluding flood basalts). Composition: Made almost entirely of basalt, a type of lava that is very fluid when melted. Structure: Because the lava is runny, it travels long distances, creating a broad, low-profile cone resembling a warrior’s shield. Eruption: Usually low-explosivity unless water gets into the vent. 2. Composite Volcanoes (Stratovolcanoes) These are the "picturesque" snow-capped peaks often seen in Japan or the Andes. Composition: Cooler, more viscous lavas (Andesitic/Rhyolitic). Structure: Layers of lava flows, pyroclastic material (ash/dust), and "bombs." Eruption: Highly explosive. The thick lava plugs the vent, building immense pressure until it blows. 3. Caldera When a volcano is so explosive that it "eats itself." The Process: They don't just erupt; they explode violently. The magma chamber beneath empties so rapidly that the structural support is lost. Result: The mountain collapses into the empty chamber, leaving a massive depression or "caldera" which often turns into a lake. 4. Flood Basalt Provinces These represent extraordinary volcanic events where lava flows for thousands of square kilometers. Example: The Deccan Traps in India. Significance: These are caused by mantle plumes and can lead to massive climate shifts due to gas release.