The Emeishan Traps constitute a flood basalt volcanic province, or large igneous province, in south-western China, centred in Sichuan province. It is sometimes referred to as the Permian Emeishan Large Igneous Province or Emeishan Flood Basalts. Like other volcanic provinces or "traps," the Emeishan Traps are multiple layers of igneous rock laid down by large mantle plume volcanic eruptions. the Emeishan Traps eruptions were serious enough to have global ecological and paleontological impact.
It is named for Emeishan, a mountain in Sichuan.
The Traps
The eruptions that produced the Emeishan Traps began 265 million years ago (Ma) or earlier. The main eruptive period is between 262 Ma and 261 Ma, and the volcanism activities end 259 Ma.
In volume, the Emeishan Traps are dwarfed by the massive Siberian Traps, which occurred, in terms of the geological time scale, not long after, at c. 252 Ma. The Emeishan basalts covers an area of more than 2.5 × 105 km2 with thicknesses ranging from several hundred meters up to 5.5 km (the average flood basalt thickness throughout the entire region is estimated to be ~700 m), but the Emeishan traps may have initially covered an area as much as 5 × 105 km2. Thus the entire volume of the Emeishan basalts to be 0.3 × 106 km3. Evidences of Emeishan volcanology suggest that the initial volcanism of the central ELIP occurred in a deep submarine environment without any significantly pre-volcanic uplift.
The Emeishan Traps are associated with the so-called end-Guadalupian Extinction or End-Capitanian extinction event, the extinction of animal and plant life that occurred at the end of the Capitanian stage of the Guadalupian epoch of the Permian period. Intertrappean limestone show the extinction to occur immediately below the first eruptive unit and marked the mass extinction occurred at the onset of explosive Emeishan volcanism. The onset of volcanism is violent phreatomagmatic-style eruptions forming volcaniclastics suggest that such effects are likely to have been severe. The synchrony between the Emeishan Traps and the end-Guadalupian extinction has been taken to support the argument, supported by Vincent Courtillot among many others, that volcanism is the main driver of mass extinctions.