Environmental factors for around 187 million years ago in the future Bredon Hill area
Rock Name
Dyrham Formation (former name Middle Lias)
Lithology (appearance)
Pale to dark grey and greenish grey, silty and sandy mudstone, with interbeds of of silt or very fine-grained sand (locally muddy or silty).
Period
Lower Jurassic
How old
Around 187 million years
Environment of rock formation
Silty sea becoming shallower over time.
Climate
Subtropical
Latitude
45′ N of Equator
Oxygen as percentage of atmosphere
20% (21% today)
Carbon Dioxide as parts per million of atmosphere composition
1000ppm (around 415ppm today and rising)
Maximum day time temperatures
29’C
Minimum night time temperature
12’C
Sea temperature
24’C
Weather risk
Seasonal storms
Midday Sun
High in southern sky
UV index
8
Earthquake risk (scale 1 low risk to 9 high risk)
6
Tectonic
Crustal extension due to opening Atlantic
Volcano risk
None in area
Top predator
Icthyosaurus
Animal Life
Pleiosaurus – Ichthyosaurus – bony fish – Ammonites
Plant Life
Cycads – Ginkgo – ferns
Humidity
High
Rainfall
Winter season high
Wind
SE?
Day length
23 hours
Days in year
385