BasaltPillowLavaAuflagerungen

Basalt pillows are a distinctive geological formation found in volcanic rock. They are characterized by their rounded, pillow-like shapes, often several meters in diameter. These structures form when basaltic lava erupts underwater or when lava flows into water. The rapid cooling of the outer surface of the lava by the water creates a hardened crust. As more lava flows from within, the pressure causes this crust to break, extruding more lava which then cools and forms another rounded lobe. This process repeats, creating a series of interconnected, pillow-shaped masses.

The interior of a basalt pillow often remains molten for a period, and as it cools, it can solidify into a glassy or fine-grained texture. The outer surface is typically a dark, glassy rind, which may be scoriaceous (full of vesicles or gas bubbles) due to rapid cooling. Internally, the rock is generally more crystalline. Pillow basalts are common in oceanic crust, where volcanic activity is prevalent at mid-ocean ridges and seamounts. They are also found in regions where ancient oceanic crust has been uplifted and exposed on land. The study of basalt pillows provides valuable insights into the conditions of underwater volcanic eruptions and the formation of oceanic lithosphere. Their characteristic morphology makes them easily recognizable in the geological record.