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  • Writer's picturePenrith and Eden Museum

Ages of Eden - Geology Gallery, Part 1

Updated: Aug 25, 2020



Caption display cases in the geology gallery


Caption - Ages of Eden museum panel from Ages of Eden exhibition, showing two images, one of volcanic lava, the other shows Eycott Hill, a rocky volcanic landscape.


Some of the oldest rocks in Cumbria result from continental collisions and violent activity some 470 million years ago. The continents were different sizes and shapes from today - and this area was the south of the Equator! Earth movements later raised these deposits far above sea level and they now form the Lake District mountains. Outcrops of some of these ancient rocks occur in Eden, such as the volcanic lava seen above.



GRAPTOLITES

These free-floating colonial animals were very common in the early oceans, but are now extinct. They evolved into many different forms and geologists find them useful in dating rocks formed from sea-bed deposits. Keswick area




Caption - Images show two graptolites.




TRILOBITES

Trilobites mainly bottom-dwelling animals of ancient seas. They were segmented and had many pairs of jointed legs. There were many different kinds, but by about 250 million years ago the group had died out. (Specimen non-local)


Caption - image shows a Trilobite





A rare specimen found near Penrith in 2011 by schoolboy James Gee has been loaned for temporary display in the museum.





Caption - Trilobite with a one pence coin, next to it to illustate its size.


Trilobites are rare in the ancient rocks of Eden. A local schoolboy found this one at Keld Gill near Penrith in 2011. It is a species of Novakella, itself a very rare type. The Natural History Museum, London were delighted to study this specimen. The head end is largely missing, which made the specimen difficult for them to name.






VOLCANIC LAVA FROM EYCOTT HILL

The spotted appearance of this rock is due to the large crystals of feldspar. Eycott Hill is a few miles west of Penrith. It is an isolated ouctrop of the rocks that form much of the Lake District. Like other volcanic rocks, it does not contain fossils.



Caption - image shows a volcanic piece of rock









Some 350 million years ago the Eden area was at the edge of shallow tropical seas near the Equator. Some of the sea-bed deposits of these times have become the limestones of the Pennines and Eden Valley. Some beds of limestone have been exposed as 'pavements' by the action of ice in the last few million years.





CRINOID or ‘SEA LILY’ fossil

Relatives of the starfishes, these ‘stalked’ animals were very abundant on the rocks and reefs of the tropical seas which once covered Eden.

(Find-spot unknown)


Caption - image shows a Crinoid or 'Sea Lily' fossil







AMMONOID fossil

Common in the tropical seas which would have covered Eden about 320 million years ago. The modern ‘Pearly Nautilus’ is a near relative of these extinct molluscs. Voreda, Plumpton (context uncertain)



Caption - image shows a a Ammonoid fossil








FERN FROM COAL-AGE SWAMPS

About 300 million years ago, low-lying swamps were often drowned by changing sea levels. Over time some became beds of coal. Primitive plants of that period were often found fossilised in these rocks. West Cumbria




Caption - image shows a fossilised Fern.








A 320 MILLION YEAR OLD SEA-BED

Fragments of corals, bryozoans (‘sea-mats’), brachiopods, trilobites and crinoids (‘sea-lilies’) show the richness of the seas which once covered Eden. Red Hills, Penrith



Caption - image shows stone with numerous fossils.








CORAL fossil (Syringopora)

Corals are tiny animals that form fixed plant-like colonies. They would have been common in the shallow tropical seas of Eden over 300 million years ago. Orton, Cumbria











Caption - image shows three images of sandstone formations


Around 290 million years ago, the land that is now Britain was just north of the Equator. It was part of a huge 'super-continent' - Pangea - that later split to form the modern continents. The Eden area would have looked like the picture on the left above. Its red sandstones have been formed from wind-blown sands from the erosion of desert rocks.


GYPSUM FROM KIRKBY THORE

Gypsum and anhydrite (both sulphates of calcium) were deposited in the Eden valley when shallow seas evaporated. Gypsum has different forms, depending on the conditions under which it was deposited. Top left - ‘Satin-Spar’; Bottom -‘Daisy-bed’ gypsum; Top right - Massive form










‘MILLET-SEED’ SANDSTONE

A coarse-grained local sandstone, formed from wind erosion of the rocks of the Eden deserts

Caption - image shows a grainy rock orange in colour.







A FOSSIL FOOTPRINT IN THE EDEN DESERT?

Rare footprints of early types of reptile have been found in the Eden sandstones. This is from a period well before the age of the true Dinosaurs. Experts are uncertain about exactly what this footprint-like mark actually is – including the possibility that despite appearances, it is the result of natural geological processes. Current research may reveal the answer. Bowscar Quarry, Penrith

Caption - image shows a piece of sandstone with an imprint of what could be a footprint of an unknown creature.








Caption - Three images, glaciers, shap granite boulder and Glencoyne, Ullswater.


The last 'Ice Ages' occurred at various times during the past three million years (above left). Glaciers of moving ice carved and shaped the landscape, smoothing out mountain valleys. The final melting of the ice left other tell-tale signs, such as deposits of clay, sand and gravel. It also moved large boulders long distances (centre: Shap granite boulder on resting limestone, Orton).




After the ice......

The latest of the Ice Age cold period ended some 12,000 years ago. As the climate warmed, woodland established and humans colonised. The earliest traces of these hunter-gatherers are their stone tools and weapons. The earth's climate continues its cycles of chnage, now for the first time affected by the activities of the human race.


Caption - Image of a flint arrow headm around 4000 years old.















ICE-SCRATCHED BOULDER

The surface of this small boulder from the Eden valley bear scratch-marks made when it was carried by an Ice Age glacier.



Caption - small round grey boulder, will scratch marks





ICE-TRANSPORTED ROCK: ‘ERRATICS’

Distinctive Eden rock types, such as Shap granite (left) and Eycott Hill lava (right) are often found far from source. Geologists can use them to help work out the routes of the Ice Age glaciers that carried them.










Caption - Image shows aerial photo from a glider: High Cup Nick, Dufton, by Sandy McCarthy 2011, of a mountainess landscape amongst cloud formations.


Overlooking the eastern side of the Eden valley, the North Pennines range up to almost 900 metres in height. They are formed from deposits laid down in tropical seas over 300 million years ago.


The crags seen near the rim of the High Cup valley (left, foreground) are the Whin Sill, a layer of igneous rock penetrating the layers of older sedimentary rocks. The smooth, regular U-shape of the valley is a tell-tale indicator of the action of glaciers during the Ice Ages of the past 3 million years.















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