Saturday, October 20, 2018

Pondering the Precambrian #11

Proterozoic:

NeoProterozoic:

The problematic Orbisiana fossil from the Ediacaran of Russia is reevaluated.

Ediacaran life formed complex ecological communities.

Dickinsonia is confirmed to be an Ediacaran animals.  In fossils from the White Sea, molecular traces of steroids were found.

There is more evidence of sponges being present on the sea floor during the Cryogenian.

Precambrian Research is doing a special issue on the Cryogenian and especially the Tonian/Cryogenian transition.

There is evidence of the Rodinia supercontinent breakup during the Tonian.

MesoProtoerozoic:

From during the Stenian, there is evidence of an intracontinental rift forming in Australia.

There is evidence the shallow waters of the MesoProterozoic were anoxic.

Where and when did the PaleoAsian Ocean form?   Another view.

PaleoProterozoic:

There is evidence Africa and Brazil were part of the Congo-Sao Francisco continent during the PaleoProterozoic and of mountain building from that timeframe.

Carbonatite found in China gives a precise time for the beginning of the breakup of the Columbia supercontinent during the Orosirian.

Archean:

There is evidence of sulfur munching microbes from NeoArchean hydrothermal system ~2.7 billion years ago.

The oldest known paleosols - soil fossils - may have been found and date from the EoArchean.

The trace fossils from the PaleoArchean attributed to life might NOT be anything of the sort.

Hadean:

Hadean into the Archean, Earth seems to have lost an ocean's worth of water.  Or at least the hydrogen from it.

There is evidence suggesting there might have been banded iron formations and chert deposits laid down in the Hadean.

Do plate tectonics date from the Hadean?!

Origin of Life:

A new timeline has been proposed for the evolution of life.

What was the origin of life in the Hadean to PaleoArchean?

What was the time period for the origin of life?

Aging may have been a fundamental property of life and dates from life's actual origin..

Could formamide been the original prebiotic solvent?

Did liquid crystals help with the formation of life?

The ancestral eukaryote is slowly being understood.

Ws early photosynthetic life on Earth purple?

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