Environmental factors for around 484 million years ago in the Voyage area
Barnt Green Voicanic Formation
Coarse grained green tuffs, grey sandstones, purple/dark brown grits with some calcite veins and thin bedded siltstones and mudstones, which appear to have been laid down in water and were intruded by a few microdiorite dykes after their deposition.
Around 484 million years
Environment of rock formation
Shallow marine – shelf sea – resulting from marine transgression
Warm. Greenhouse Earth
57′ S of Equator
Oxygen as percentage of atmosphere
19% (21% today)
Carbon Dioxide as parts per million of atmosphere composition
4400ppm (around 415ppm today and rising)
Maximum day time temperatures
Minimum night time temperature
High winds. Rough seas. Lightning. Thick ash falls
Very low in northern sky
Earthquake risk (scale 1 low risk to 9 high risk)
Violent volcanic activity – subduction of oceanic lithosphere.
Severe. Ash falls. Hydrogen sulphide and toxic gasses.
Lower Ordovician microfossils (acritarchs)
First primitive land plants
Days in year