Question

### Models of the Permian-Triassic Extinction Event

The Permian-Triassic (P-Tr) extinction event, which occurred approximately $252\text{ million years ago}$, resulted in the loss of over $90\%$ of marine species. Geologists have proposed different models to explain the cause of this mass extinction.

Model 1 (Volcanic Outgassing Model)
This model proposes that the eruption of the Siberian Traps, a massive region of volcanic rock, released enormous volumes of carbon dioxide ($CO_2$) and methane ($CH_4$) into the atmosphere over a span of several hundred thousand years. This led to rapid global warming of approximately $10^\circ\text{C}$, causing severe ocean acidification. Warm oceans absorbed less oxygen, leading to widespread ocean anoxia (oxygen depletion), which suffocated marine life.

Model 2 (Bolide Impact Model)
This model proposes that a large asteroid or comet (bolide) collided with Earth at the P-Tr boundary. The impact vaporized target rocks containing anhydrite ($CaSO_4$), releasing massive quantities of sulfur dioxide ($SO_2$) into the stratosphere. This caused global cooling and severe acid rain. The subsequent collapse of land and ocean food webs led to massive organic decay, which depleted dissolved oxygen in the oceans, causing widespread marine anoxia.

Instruction:
Based on the models provided, match each description of an extinction trigger, mechanism, or timeline on the left with the model(s) on the right that it describes.