Chemical Composition
Different lava types form based on their chemical composition, primarily silica content. Basaltic lava contains low silica levels (45-52%), flowing easily and creating smooth surfaces. Andesitic lava has intermediate silica content (52-63%), while rhyolitic lava contains high silica (>63%), resulting in thick, slow-moving flows. These compositions determine eruption characteristics and final rock formations.
Flow Behavior
Lava flows exhibit distinct patterns based on composition and cooling conditions. Pahoehoe lava forms smooth, ropy surfaces as thin crust folds over flowing material. A'a lava creates rough, jagged surfaces due to rapid cooling and high viscosity. Flow speed varies from walking pace for basaltic lava to extremely slow movement for silica-rich flows.
Cooling Structures
As lava cools, it forms characteristic structures. Rapid cooling creates volcanic glass, while slower cooling allows crystal formation. Columnar jointing develops in thick flows, creating hexagonal columns. Lava tubes form when surface crust insulates flowing channels, leaving cave-like structures after drainage. These features influence local topography and create unique geological formations.Shutdown123