The Carboniferous Period (290-366 million years ago) was an important time for Britain which would ultimately lead to the industrial revolution of the Victorian era and the rise of the British Empire. This was down to the coal that was mined from the rocks of this age. This coal was formed from the decaying plants that grew in vast swamps across the country when it was located close to the tropical equator. This month’s blog looks at the plants that grew across Britain at this time.
Fossil Grove
One of the best places to visit a fossil forest from the Carboniferous is at Fossil Grove, located in Victoria Park, Glasgow. This museum shows the evidence for great dense forests in Carboniferous Britain. Here, the casts of 11 lycopod tree stumps are preserved where the trees once grew and form one of the best ‘in situ’ fossil examples of these trees in the World. Their scientific importance was thankfully recognized by the quarry workers who revealed them in 1887, who constructed a protective museum building around them, thus creating one of the earliest ‘geo-tourism’ sites in the World.
Lycopods are a subgroup of plants that are defined as having one single vein per leaf to distribute water and nutrients (rather that complex branching veins). Such plants can still be found today, clubmosses for example. In the Carboniferous one such plant was the Lepidodendron, or ‘Scale Tree’ (so called due to its scale like trunk pattern). These plants reached 30 m in height with tall trunks topped with a crown of branches with grass-like leaves.
Lycopod Forests
The nature of these forests is illustrated well at Barns Ness in East Lothian, where potholes on the wave-cut platform represent the site of a Lepidodendron tree (Figure). The hollows are each about one meter across and would have formed a dense mangrove. The roots of these trees are are named Stigmaria and are commonly seen below coal layers in Carboniferous strata and are recognized by their characteristic mottled pattern. At Barns Ness numerous examples can be seen (Figure).
Lepidodendron were important coal-forming trees in the Carboniferous, however they were one of a number of extinct species found in the UK at this time. The largest tree fossil to be discovered to date is a Pitus Withamii tree fossil, which was excavated from Craigleith Quarry in Edinburgh. It now sits in the Royal Botanical Gardens stretching 10.5 m across the Fossil Courtyard (Figure). Other fossils plants that have been identified from this period are the Sigillaria and Fern Trees.
The decay of these dense forests upon death has gone onto form the coal seams of the UK, and much of the gas in the Southern North Sea, and have been central to the industrial development of the country.
-- Happy Exploring --
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