Corstorphine Hill provides one of the most accessible locations in central Scotland to examine the effects of glacial erosion on a band of hard rock. Here a thick quartz dolerite sill provides the tough, jointed rock in which roches moutonnées are typically formed.
What is a roche moutonnée?
In glaciology, a roche moutonnée ("rawsh mootenay") is a rock formation created by the passing of a glacier. When a glacier erodes down to bedrock, it can form tear-drop shaped hills that are oriented in the direction of flow.
The appearance of the erosional glacier feature is very defined: a rock formation where all the sides and edges have been smoothed and eroded in the direction of the glacier that once passed over it, with the exception of the rough and craggy downstream or lee side. It is this side that has been subjected to "plucking", the erosional process in which ice melts slightly by pressure and seeps into cracks in the rock. When the water freezes, the rock is attached to the glacier and eventually ripped away from the landform as the glacier continues its forward progress.
They are often marked with glacial striations (scratches) inflicted by pebbles embedded in the undersurface of the ice. These too, allow the flow direction to be ascertained.
The term "roche moutonnée" comes from the French for "fleecy rock", despite its popular misinterpretation as "rock sheep".
The Task
To claim this cache, you will have to climb to the top of Corstorphine Hill and answer the following questions.
But before doing so please take note: If you have an internet connection to log your find, then you have an internet connection to send me the required answers! Send your answers BEFORE posting your log. Failing to do this will result in the deletion of your log without notice. You DO NOT have to wait for a reply. If I have an issue with your email I will contact you about it.
Now down to the questions.
1. Using the above information, determine from the rock feature, which you are standing on, in what direction did the glacier flow?
2. Optional: Get a photo of yourself on top of rock formation.