How the Welsh landscape was transformed by events in Turkey – 300 million years ago

Turkey may seem a long way away to the people of Wales. But events there some 300 million year ago have had a profound and lasting effect, on our Welsh climate, landscape and wildlife.

For about 10 million years, Wales was part of an enormous tropical swampland extending from eastern North America to Turkey and the Caucasus. The dead remains of the plants that grew there caused massive deposits of peat to build-up. This peat was then buried by mud and sand, and the resulting heat and pressure changed it into the coals on which much of the industrial growth of places such as Wales depended, especially in the 19^th and early 20^th centuries.

But nothing lasts for ever, and the swamps eventually dried up and the accumulation of the economically important coal-forming peat came to an end. What caused this profound change to the environment has been the subject of much scientific debate. Research co-ordinated from Amgueddfa Cymru–National Museum Wales (as part of the International Geoscience Programme project IGCP 575) suggests that it was due to the combination of two major factors.

1. Landscape Change: The collision of two large continental plates (Euramerica and Gondwana) caused a massive upheaval of the landscape, with rivers changing direction and new mountain ranges forming. The effect of these changes was particularly felt in the areas where the swamps had been.
2. Climate Change: The changing landscape caused a different type of vegetation to grow here, and this coincided with a significant warming of the climate and a reduction in rainfall.

Importantly, these environmental changes started first at the eastern end of these swamplands, in places such as northern Turkey, and then progressively moved westwards towards Wales.

So, in order to understand properly what caused the collapse of this ancient wetland in Wales, we need to study events in Turkey. To do this might have needed extensive (and expensive) field excursions to the area. Fortunately, we have a scientific resource nearer to hand that can provide at least a start to this work. In the years just before and after World War II, the great Dutch palaeobotanist Wilhelmius Jongmans led expeditions to northern Turkey to collect Carboniferous plant fossils. He sadly died before he could properly work on them. Fortunately, however, his collection of over 5,000 Turkish fossils is now stored safely in the Naturalis Museum in the Netherlands.

Chris Cleal from Amgueddfa Cymru–National Museum Wales is now leading a collaborative project with colleagues from the Netherlands, Germany and the UK, to research this collection – using expertise developed in Wales to bear on an internationally important problem. It will help us understand what controlled the formation of coal deposits such as those found in Wales, and how vegetation, atmosphere and climate interacted in Carboniferous times. 

The world 300 million years ago was in many ways similar to today (far more similar to what it was in the intervening millions of years ago, for instance in Mesozoic times, when the dinosaurs were roaming around). Studying how climate, vegetation and the atmosphere interacted in this ancient world therefore allows us to check some of the assumptions on which scientists have been basing their modern-day climate models.

This shows the importance of international collaboration between museums in scientific research – why it is vital for scientists in Wales to work with colleagues from across the world.