Mam Tor - Photos

Mam Tor from the east.  The moving slip is in front and right of the camera.  White patches are snow. Geology.
Close up of the slip scarp; the highly layered nature of the Mam Tor Beds, showing a regular cycle of (now) crumbling shales and sandstones is clear. That the face is still being actively eroded is made clear by the lack of plants.   The Edale Shales, lower in the series, are even weaker and failed, initiating the original slip. All were formed at the edges of an immense delta that covered the area about 320 million years ago during the Namurian phase of the mid Carboniferours. The main delta laid down sandstones  - what we now see as grits - whilst finer muds were carried to deeper water by slumps & currents and eventually formed shale grit and shale.
Looking east  across the scarp towards Lose Hill.  For the technically minded, these are the Mam Tor Beds of the Millstone Grit series. The underlying  Edale Shales are not exposed as they are covered by the slip.
Repeated movements of the slip, which is around 750m long,  have produced an apparently chaotic surface, although individual movements were probably simple rotations. The centre of the slip was reported to be moving 50cm annually in a paper published in 2003.    White patches are snow.   Underneath the slip is a layer of Edale Shale. This layer has provided a slip surface for the blocks above as it has decayed.

At the top of the image are lead workings that exploited the minerals in the limestone that underlies the whole area.
Once the A625 -  the Mam Tor slip.  Throughout the 20th century, repairs were made  with various forms of asphalt, now exposed like a layer cake in sections a metre or more thick, as the underlying grit and shale moves downhill.
The north west side of Mam Tor from Rushup Edge. Various tracks and the Bronze Age fortifications are picked out by snow. Although various hummocks - the remains of rotational slips - can be seen along the line of the road, this north side seems currently stable.

Copyright © 2010 Stephen N.Wood. All rights reserved.