Glen Artney Donalds - Fingal's Putting Stone
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This cache is one of a series of caches up in the hills here.
The cache is on a circuit of the hills to the South of Glen Artney. At the summit of Meall Clachach is a large erratic boulder known colloquially as Fingal's Putting Stone. The view from the top is superb especially looking North to the Highlands.
The series is described from a clockwise direction so you would approach Meall Clachach from Uamh Bheag. It is a straighforward section of the walk following the fence line down. Equally you could approach from Am Beannan.
The Glen Artney hills are situated just south of the Highland Boundary Fault which separates the more mountainous West Highlands from the Central Lowlands (Midland Valley).
The distinction between the long rounded, rolling hills here of the Lowlands and the mountains of the Highlands is very apparent here when you look to the North.
Glen Artney is defined by a clear valley along which the Water of Ruchill flows northeast and then north to join the River Earn near Comrie.
The Highland Boundary Fault can be traced NE–SW across Scotland for around 240 km and defines the northern margin of the Midland Valley. At this point it runs parallel to the Glen.
Ben Vorlich 985m is the mountain immediately to the North. The geology of this mountain is very different from the sandstone bedrock of Meall Clachach with its smooth grassy and heather covered slopes. Ben Vorlich is on the broad band of rocks which run parallel to the Highland boundary. Mica Shist and Shistose grits dominate here. These rocks were once sediments of sandstones and shales but have metamorphosed by heat and pressure over millions of years. There are significant intrusions of other rock forming parallel bands. These rocks include granites, limestones, quartzites and intrusive diorite.
At between 600 and 900 metres there is a pronounced transition from heather and grass moorland to the arctic alpine zone with many screes, rock outcrops.
A short distance south South from Meall Clachach on the top of Uamh Bheag (the highest hill here at 664m) if you look South East the whole vista of the Forth valley (Midland Valley) opens up. The rocks of the Scottish lowlands are very different from the mountains of the north. In the midland valley, some of Scotland's youngest rocks cover over the older crust. Nearly 400 million years ago, the newly formed continent began to be pulled apart.
Tectonic movements created major faults which created the outline of Scotland from previously scattered fragments. One of these faults is the Highland Boundary Fault, separating the Lowlands from the Highlands.
The result in the Lowlands to the south was a rift valley, covered with a rash of volcanoes and a hole filling with sediments being washed from the high ground to the north and south. Look South from here towards Scotland's central belt, and the hills that define the landscape such as the Campsies and the Ochills are all the result of volcanic activity during the Carboniferous Period.
The bedrock on the hills in Glen Artney, though, is old sandstone covered in peat which has been deposited over the last 12,000 years. It is only in areas where it is exposed and weathered are you able to see the pebbly sandstones of the Glen Artney hills.
Many of these sediments in the Midland Valley have had economic significance as the coal and iron bearing rocks formed during the Carboniferous period fuelled Scotland's industrial revolution.
At Uamh Mhor N56°16.434', W004°07.234' there is a Dolerite dyke which has been traced from a point where it crosses the Dunning Burn above Pitmeadow N56°17.753', W003°34.241' at intervals through the hills north of the Braes of Doune and Uamh Mhor, and across the Highland boundary fault, where it enters the Highland schists, near Callander, a total of 30 miles.
The rocks here, being much more durable and resistant to erosion than the surrounding sedimentary rocks have created a wonderful mini rift valley.
Glaciation
Several ice ages shaped the land through glacial erosion, creating u-shaped valleys like Glen Artney. The ice sheet helped carve the glens and lochs that surround the mountains today, affecting almost every aspect of the visual landscape. The glaciers carried huge boulders many miles. When the glaciers retreated - the last major incursion of ice peaked about 18,000 years ago, it left other remnant features such as erratic boulders like the one here.
They are called erratics because they are different from the bed rock of the area. Erratics and erratic trains are relatively widespread in Scotland. Erratics are useful indicators of patterns of former ice flow.
We know the boulder on Meall Clachach is an erratic because of a number of points. The boulder is on the very highest point of Meall Clachach and could not have got there by debris from cliff erosion for example. It therefore must have been transported and deposited by a glacier.There are marks on the boulder which indicate it has been moved by the glacier and scored on the surface in a particular way.
Erratic boulders in Scotland have been found large distances away from their "parent" rock formations. This is unlikely the case with this erratic, as the rock type is sandstone ( as is Meall Clachach)although appears to be different from the rock seen nearby where it has been exposed by weathering on Creag na Craoibhe.
Coire na Fionnarachd to the east, contains boulder trains but it is quite probable these have fallen from the crags as the rocks have much sharper edges in contrast to the erratics.
On the North slopes of Uamh Bheag are some other smaller, erratic boulders, but which have very clearly defined lines on them. (see photograph).
The boulders are rounded and smoothed in a remarkable manner. There are some deep groves and finer lines over the surface, This indicates which way the glacier sheet passed over these hills, which we know was roughly from SW to NE following the line of Glen Artney.
IMPORTANT
In order to log the cache
1. measure the boulder and estimate the volume in cubic meters.
2. Take a photo of yourself (if possible) with gps at the boulder with the camera pointed towards the line of the Highland boundary fault.
Once you have the answer please email me this info (Do not post the answer in your log!!)
Please post lots of other photos on the cache page. I would welcome any other interesting erratic boulders that you find on the hill.
Robert Burns: Scotland’s Bard was born in the c18th during the ‘Age of Enlightenment’ but also in a time when the country superstitions and supernatural beings were an integral part of folk belief. The fear of the Devil , witchcraft and the supernatural was still very real for many people. Robert Burns was sceptical about such supernaturnal powers.
The Address to the De’il for example is a poem that pokes fun at folk beliefs about the Devil and his powers.
In those days, huge out of place rocks such as on Meall Clachach, were seen to have been deposited by the Devil, and often given corresponding names such as Devils Chair.
One wonders what Burns might have made of the hills here had he visited?
As Burns did not write about mountains of Scotland I will have to rely on William Wordsworth who perhaps described an erratic? in ‘The Leech Gardener' 1807
"As a huge Stone is sometimes seen to lie
Couched on the bald top of an eminence;
Wonder to all who do the same espy"
**** congratulations to the Swedish Cachers on their FTF*****
Additional Hints
(Decrypt)
Lbh ner cebonoyl erfgvat ba vg.