Géosciences - Blog Posts
Pour mes fellow français out there si on rapportait l'histoire de la Terre sur une année, actuellement on serait au niveau de l'equateur, il ferait chaud sa grand-mère, les massifs anciens genre armoricain (c'est les granites en Bretagne) s'érodent mais les Alpes et les Pyrénées existent pas encore...
On est presque mi décembre et quasi toutes les structures que j'ai étudié en géologie sur des cartes depuis le début de ma scolarité n'ont pas encore été créées. La méditerranée n'existe pas encore... l'Atlantique non plus...Et on est mi décembre...
IT'S TIME FOR PERMIAN WEEKEND BABEY!!!
Do you like volcanoes but wish they were bigger?
Would you like to see the world choked with smoke?
Do you in all your cosmic power feel like things need a hard reset?
Then the Permian period might be for you!
Lasting from 298.9-251.9 Ma, if you compressed all of Earth's history into a year, December 7th-11th would mark the Permian period.
While it did see some innovations in life with the continued diversification of therapsids and sauropsids as they spread around Pangaea, the period is mainly known for mass extinctions, of which there were at least three.
The first was fairly minor in comparison to the others, where the end of the early Permian saw the extinction of several groups of early land vertebrates such as Dimetrodon as other tetrapods gained prominence.
And then, some time in the mid Permian, the sea began to erupt.
The Emeishan Traps are a formation in China where basalt covers an area extending approximately 250,000 square kilometers, which is roughly the size of the state of Michigan. It could have originally been twice that size, covering an area larger than the state of California with volcanic deposits an average of 700 meters thick. Originating on the sea floor, it released massive amounts of sulfur and carbon dioxides, wreaking havoc on the world's climate. A recent paper published in the journal Geology also makes the case that the eruptions also managed to heat up oil and gas deposits in the area, cooking them underground and leading to the release of even more carbon dioxide and methane gas.
Estimates on the impact of this eruption vary, but around a third of marine life went extinct, and the majority of survivors on land were burrowing animals.
This was already about as significant as the extinction that would kill the non-avian dinosaurs in the late Triassic Cretaceous in terms of severity, but it would soon be eclipsed by the single worst mass extinction in Earth's history: the end Permian, or "The Great Dying".
In what is now modern day Siberia, another massive series of eruptions took place, forming the Siberian Traps. Over the course of two million years, around a million cubic miles of basalt were laid down over an area of 7 million square kilometers. This was 14 times the size of the Emeishan Traps, and covered an area roughly the size of Australia. Most of it erupted in the first million years. The massive amounts of carbon and sulfur dioxide released led to dramatic ocean acidification and climate change.
It is speculated that the traps also lit coal fields on fire, adding to their emissions. This, combined with a possible contribution from a meteorite impact on the other side of the world led to mass die offs.
81% of Marine life, and 70% of terrestrial species went extinct.
On land, it is estimated to have taken nearly 30 million years for life to recover.
As heavy as that is though, it did recover.
When the dust settled, there was still life in the oceans, and plants still grew on the land, and animals came out from their burrows, blinking in the light of a new day. And they lived.
New species would come. Life would be made new. The sun continued to shine, and rain continued to fall, and in the end the Earth had made it through.
Life found a way to make it through a level of destruction beyond anything we have ever seen or could imagine as a species. And, with a little bit of hope, help, and luck, so can we.
Edit: ( Mistakenly wrote "Triassic" rather than Cretaceous)
Watercolour on paper - Patella Vulgata (the common limpet)
My best friend analyzed rare earth element patterns in a series of shells - including one from the common limpet - for her bachelor thesis, this is an illustration I made for her presentation :)