the emeishan traps in southwestern china, around sichuan province, the deccan traps of central india, the siberian traps, and the columbia river plateau of western north america are four large regions covered by prehistoric flood basalts. the two largest flood basalt events in historic time have been at eldgjá and lakagigar, both in iceland. the largest and best-preserved continental flood basalt terrain on earth is part of the mackenzie large igneous province in canada. the maria on the moon are additional, even more extensive, flood basalts. flood basalts on the ocean floor produce oceanic plateaus.