 Large igneous province

A large igneous province is a geographically extensive accumulation of igneous rock emplaced in unusually large volumes over a comparatively concentrated geological episode. Surface lava flows can be accompanied by substantial dikes, sills and deeper intrusive material, so mapped lava area alone does not measure the total magmatic addition.

Its physical effects depend on emplacement rate and environment as well as volume. Rapid gas release can alter atmospheric composition, and intrusions can heat surrounding volatile-bearing rocks. The Siberian Traps and Deccan Traps illustrate why eruptive chronology, intrusive volume and gas production must be measured separately when testing environmental consequences.