The Permo-Trias - 290-208 million years ago

The Permian Period began 290 million years ago and ended 245 million years ago. There are no rocks of Permian age in South Gloucestershire but the period is important because of the effect on the landscape of the time.

Following the Carboniferous Period the region continued its journey into latitudes north of the equator where hot arid conditions prevailed.

Large-scale earth movements had brought about the formation of a super-continent containing most of the earlier separate continental landmasses. The tip of this super-continent covered the South Pole, such that landmasses were glaciated extensively in the Southern Hemisphere. The loss of the smaller continents reduced the total length of coastline and therefore of the coastal waters, globally. The first major reptile evolution took place at this time together with the appearance of many new insects. However because of the environmental conditions at the time the Permian period was a time of mass extinction when 90 per cent of all species died out.

The mountains initiated during the Carboniferous Period were now subjected to intense erosion. There was little or no water to transport sediment or to nourish plants or animals and this barren time lasted up to 20 million years into the Triassic period.

There are no new rocks here for this period apart from the tons of erosion debris spread around the lower slopes of the heavily eroded mountains, which spans both the Permian and the Trias.

[Home] [Top] [Geological History of South Gloucestershire - Main Page]