carboniferous
The Carboniferous period succeeded the Devonian and preceded the Permian making it the 5th stage of the Paleozoic era, lasting between 359.2 million years ago to 299 million years ago. The Carboniferous period takes its name from the coal bearing rocks which are characteristic of this time and is an exception to the paleoclimate of Britain as the time with the most similar climate to Earth today. The average temperature at the beginning of the Carboniferous was 20° C but this declined and due to cooling in the middle Carboniferous the average global temperature dropped to between 10 and 12° C, which eventually lead to another ice age. Towards the end of the period the Southern hemisphere of the Earth began to form ice caps.
Periods of cooler and warmer cycles correlated with glaciation expansion and retreat. The Carboniferous period began with a great sea level rise, which could have been due to the melting of ice sheets, and water covered England and Wales. Consequently, shallowing of the sea and the formation of extensive river deltas which fed from the Northern Landmass, Scotland, created the conditions for a terrestrial environment by the end of the period. The carboniferous is known for the explosion of plant growth and the first large lizards and insects in this terrestrial environment.
The Carboniferous period is divided into an upper and lower time period, known nationally as the Mississippian and the Pennsylvanian with the boundary between the two found approximately 318 million years ago. In the Upper Carboniferous from approximately 327 million years ago, the climate became more arid, with increased run-off in Britain due to the extent of the deltas. Remains of the Upper Carboniferous period include coal beds in the Midlands and Northern England formed from the compression of dense, low lying fern and horsetail forests. Coal is mostly carbon accumulations from fossils of these deposited plant materials. Common rocks from this time also include thick layers of millstone grit in the Pennines. The Lower Carboniferous saw the deposition of marine limestones, where once tropical seas were rich in coral, trilobites and brachiopods. These features are visible in the Derbyshire Peak District and the Yorkshire Dales.
Periods of cooler and warmer cycles correlated with glaciation expansion and retreat. The Carboniferous period began with a great sea level rise, which could have been due to the melting of ice sheets, and water covered England and Wales. Consequently, shallowing of the sea and the formation of extensive river deltas which fed from the Northern Landmass, Scotland, created the conditions for a terrestrial environment by the end of the period. The carboniferous is known for the explosion of plant growth and the first large lizards and insects in this terrestrial environment.
The Carboniferous period is divided into an upper and lower time period, known nationally as the Mississippian and the Pennsylvanian with the boundary between the two found approximately 318 million years ago. In the Upper Carboniferous from approximately 327 million years ago, the climate became more arid, with increased run-off in Britain due to the extent of the deltas. Remains of the Upper Carboniferous period include coal beds in the Midlands and Northern England formed from the compression of dense, low lying fern and horsetail forests. Coal is mostly carbon accumulations from fossils of these deposited plant materials. Common rocks from this time also include thick layers of millstone grit in the Pennines. The Lower Carboniferous saw the deposition of marine limestones, where once tropical seas were rich in coral, trilobites and brachiopods. These features are visible in the Derbyshire Peak District and the Yorkshire Dales.
As tectonic plates moved together to eventually form the supercontinent Pangea in the Permian period, folds were created in carboniferous rocks in North Devon coast lines and gentle folds formed the Mendip hills. In South West England
intrusion granites can also be found.
intrusion granites can also be found.