The cause of the great Permian extinction has remained an enduring mystery. The extinction represents the end of the ancient way of life on Earth and marks the end of the Permian period. The Triassic period which followed the extinction is the first period of the Mesozoic era which is the, “meso” or, middle of three eras of life on Earth. The Mesozoic might be better thought of as the transitional era, representing the time between the ancient pre-Permian era and the modern world of the Cenozoic Era in which we live today.
There are several features of the Permian extinction event which must be addressed by any hypothesis which hopes to solve the mystery of the Permian extinction. The eruption of the Siberian traps is the feature most associated with the Permian Triassic boundary. Though it is accepted that the tremendous outpouring of volcanic material which formed the traps must have played a significant role in the extinction, it is generally believed that their must be more to the story.
A unique feature of the Permian extinction is the devastation which occurred to the shallow water marine species. These surf zone creatures were particularly hard hit by the extinction event. Interestingly, however, fresh water species seem to have been little effected. One explanation for this anomaly is that the deep waters of the oceans during the Permian period lacked oxygen and that something caused the deep ocean waters to mix with the well oxygenated surface waters, essentially suffocating the surf zone creatures. Another peculiar feature of the Permian extinction is the long time of recovery. Life hung in the balance for nearly 5 million years before genuine recovery began.
A New Model
The Close Approach Lunar Model is a comprehensive model which assigns one cause, the close approach of the Moon, to solve a myriad of problems associated with the mystery of the Permian extinction. The close approach of the Moon to the Earth at the Permian had three major impacts on the Earth. First, solid body tidal heating, similar to that found today on Jupiter’s moon Io, would have caused the massive Siberian traps which dumped huge quantities of volcanic material onto the Earth’s surface and gases into the Earth’s atmosphere.
Second, the gravitational pull of the Moon on the Earth’s oceans would have had a couple major effects, which are seen at the P/T boundary. The tidal tug of a closer Moon would drive the mixing of the deeper anoxic layers of the ocean which contributed to the surf zone extinctions. In addition the large tidal surges would replace the placid tidal zones which had existed on Earth since life first formed. This very high energy environment would make life extremely difficult, particularly for the attached and filter feeding forms of life in the surf zone. This ecosystem had previously faced the smaller tides of a more distant Moon. The disruption of the shallow reefs through tidal action brought on by the now closer Moon caused increased erosion of the shoreline and the deposit of associated sediments onto these near shore environments; a catastrophe not experienced before on such a global scale.
Finally, the most devastating thing may well have been that the Earth’s upper atmosphere was partially stripped away, exposing life to the radiation of space.
Life on Earth came closest to being exterminated at the Permian-Triassic boundary, with some 95% of shallow marine creatures and 90% of all species becoming extinct.