This is a Callander Geodiversity Trail. The publicly-accessible route is approximately 4.2km (3 miles), half of which is on paths/trails, and half along a single-track minor road. Please take care along the roads and keep an eye out for traffic when crossing.
There are three Field Tasks, highlighted in red to complete. Please remember to submit your responses (email or via the Message Centre) prior to logging this cache as Found. In addition it would be great (but not essential!) for you to share any photos of features you have observed..
STAGE 1 - Car Park
The posted coordinates will take you to the Coilhallon Woods car park, which is the start and end point for this trail.
The place we now call Callander has been shaped by extraordinary forces over millennia. It may be hard to believe nowadays, but where we now stand was once a desert-like region south of the Equator, before continental drift brought the landforms together to create Scotland. A series of Ice Ages have left their mark, from the slow advance of the ice sheets, thousands of metres thick, to the grinding of the glaciers which carved out the glens. The streams and rivers which ran within the ice have left their traces, and the last remnant of the retreating glaciers remains at the east end of the town to tell its story. A major geological feature, a little over 2 km to the north-west of Callander, is the Highland Boundary Fault, a near-vertical fracture that penetrates deep into the Earth’s crust, crossing Scotland from coast to coast, from Arran in the south-west to Stonehaven in the north-east, and separating the Grampian Highlands to the north from the Midland Valley to the south. All of these events have left evidence for us to investigate, and this Earthcache will show you where some of that geological evidence is to be found.
STAGE 2 - Dunmore Hill Fort
Dunmore Hillfort occupies the summit of the steep hillock in front of you. It is not clear when it was first built, but is likely to have been founded no later than the Iron Age and remained in operation well into the Dark Ages. The central enclosure was oval shaped and probably included a number of round houses. On the exterior, the eastern side was protected by a sheer drop whilst the west was approached via a shallower slope and a complex defensive entrance called a barbican. The fort sits on a hillock composed of a rock called puddingstone, and this particular formation is part of the "Craig of Monievreckie Conglomerate". Conglomerate rocks are formed from rounded gravel and broken pieces of larger rock which have been chemically cemented together over time.
Field Task 1 - Look around to the flatter lands at the base of the hillock. Even though this whole area was shaped by glacial ice flow, the hillock remains. Why do you think that is?
STAGE 3 - Puddingstone Boulder
Near to the Information Board is a boulder of Craig of Monievreckie Conglomerate, which may have fallen off the Dunmore Crag due to erosion in the past. This is a puddingstone rich in volcanic fragments. It is made up of rounded pieces, from the size of pebbles to cobbles, and is mainly of lava set amongst coarse sand. Other boulders of puddingstone and small exposures of similar bedrock are in this vicinity.
STAGE 4 - Split Erratic of Folded Highland Metamorphic Rock
Look for a large boulder which is neatly split along the folds of rock. This attractive minor glacial feature is a boulder over one metre in size of folded metamorphosed sandstone. It has fractured along the folding probably because of weathering and frost action since the end of the last ice age 12,000 years ago.
Field Task 2 - Examine the rock - roughly how wide is the split at the top of the boulder? Boulder's like these are known as erratics, because they do not match the surrounding geology. How do you think this huge boulder was carried here?
STAGE 5 - Samson’s Stone - Erratic of Highland Metamorphic Rock
This well-known erratic is perched on the hillside above the road. It is a geological curiosity that has probably been visited by many visitors to the Callander area over hundreds of years. It is a boulder over 3 metres in size made of folded metamorphosed sandstone brought here by nature from the Highlands in the west. Local myth alleges that the Stone was thrown here by one of the Fingalian giants in ancient times. It was originally located upon the nearby mountain of Ben Ledi nearly 3 miles northwest, and was one of several stones being thrown in a competition to see who was the strongest of the giants — and Samson was the name of the one who threw this huge rock.
Field Task 3 - The sandstone of Samson's Stone is described as "metamorphosed". This means that it has been subjected to very strong heat or pressure - what forces in nature might have caused this? Describe what patterns or colours you can see in the rock layers.
Afterwards, retrace your steps back to the car park.
I hope you have enjoyed this Earthcache. Please remember to submit your Field Task responses prior to logging this Earthcache.
Credits: Much of the above information was adapted from the "Stories in the Landscape" leaflet written by Mike Browne, in association with and produced by Callander’s Countryside, an associated organisation of Callander Community Development Trust. www.callandercdt.org.uk