Which resulting phenomenon occurs when highly viscous lava cools rapidly?

💡 Explanation

Obsidian flows, formed by rapid cooling that inhibits crystal growth, result because there's insufficient time for minerals to organize via the mechanism of rapid thermal quenching; therefore obsidian forms, rather than slower-cooled structures which allows crystallization.

• Which ecosystem collapse mechanism occurs in coastal South America during a strong El Niño event?
• Which mechanism primarily reduces lake water salinity in closed-basin lake systems over geological timescales?
• Which mechanism initially drives the thermohaline circulation following surface water cooling near Greenland?
• Which risk increases when thawing permafrost causes widespread solifluction on Arctic slopes used for pipeline construction?
• Which mechanism causes tsunami formation during a subduction zone earthquake with significant vertical displacement?
• Which mechanism primarily contributes to the steep walls observed surrounding fjords?