GEOLOGY

Detailed explanation-1: -Shield volcanoes are composed almost entirely of relatively thin lava and are built by many layers over time and the layers are usually of very similar composition. Hence, Option 1 is correct. Most shields were formed by low viscosity basaltic magma that flows easily downslope away from the summit vent.

Detailed explanation-2: -Shield volcanoes are constructed primarily of thin lava flows that cover large areas. Basaltic shield volcanoes such as Mauna Loa and Kīlauea in Hawai’i Volcanoes National Park erupt primarily pāhoehoe and ‘a’ā lavas.

Detailed explanation-3: -Shield volcanoes are built up of a great many flows of runny lava, each of which is relatively thin, only a few meters (yards) thick. Characteristic features of shield volcanoes are lava tubes, underground channels that fed the flows on the slopes of the volcano.

Detailed explanation-4: -It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more viscous lava erupted from a stratovolcano. Repeated eruptions result in the steady accumulation of broad sheets of lava, building up the shield volcano’s distinctive form.

Detailed explanation-5: -Shield volcanoes Where a volcano produces low viscosity, runny lava, it spreads far from the source and forms a volcano with gentle slopes: a shield volcano. Most shield volcanoes are formed from fluid, basaltic lava flows. Mauna Kea and Mauna Loa are shield volcanoes.