Final answer:
A volcano with steep slopes composed of alternating layers of lava and pyroclastics is called a stratovolcano or composite volcano.
Step-by-step explanation:
Volcano with Steep Slopes and Alternating Layers of Lava and Pyroclastics
A volcano with steep slopes composed of alternating layers of lava and pyroclastics is known as a stratovolcano or composite volcano. These volcanoes are characterized by their explosive eruptions and the accumulation of layers of lava flows and pyroclastic material such as ash, tephra, and volcanic bombs. The alternating layers form as the volcano alternates between effusive eruptions that produce lava flows and explosive eruptions that generate pyroclastics.
For example, Mount Vesuvius in Italy is a well-known stratovolcano that erupted in AD 79, burying the ancient Roman cities of Pompeii and Herculaneum under layers of ash and pyroclastics. Another example is Mount St. Helens in the United States, which had a major eruption in 1980, resulting in the collapse of its northern slope and the deposition of volcanic ash.