Geological History of Saddleworth

The rocks exposed in the Saddleworth region reveal a fascinating history of how the land around us was formed. The typical rocks exposed here are commonly known as ‘millstone grits’ due to their coarse sandstone texture. These feldspar and quartz rich deposits are dominant but are associated with siltstones, mudstones, marine shales and minor coal deposits which can also be seen in the area. This rock group has an average thickness of around 2000m.

The origin of these geological facies lies in the Carboniferous period which spans from 355-290 Million years ago. More specifically, the Saddleworth region reveals sediments of Upper Carboniferous age and therefore date between 310-290 Million (Ma) yrs before present (BP). At this time, Saddleworth (and indeed the British Isles) had a very different climate as a result of its dramatically different position on earth. Magnetic analysis of the geological rock record has revealed an apparent ‘polar wandering’ where it is clear that the British Isles have gradually moved from the southern hemisphere to our present latitude in the sub-polar northern hemisphere. (See fig 1 below)

Fig 1