Question: how are basaltic magmas thought to be formed?
Answer: Basaltic magma is formed through dry partial melting of the mantle. The mantle lies just below the crust of the earth. Basalts make up most of the ocean's crust; this is why basaltic magma is typically found in oceanic volcanoes. ... The partial melt contains both liquid and crystals that need a higher temperature to melt.