Cenozoic weathering covers in Buchan, Scotland and their significance

Abstract

Isolated occurrences of chemically weathered rock or saprolite are common in many formerly glaciated areas around the North Atlantic1–6. These pockets of saprolite are widely regarded as remnants of Cenozoic deep-weathering covers which existed before the first extensive Northern Hemisphere glaciations at ∼2.4 Myr (ref. 7) and their apparent survival has long been used as evidence for the local ineffectiveness of glacial erosion2,4,8,9. However, the scarcity of correlative deposits means that the age and significance of these fragmented saprolites are uncertain. I report here the results of a detailed survey which shows that in Buchan, Scotland, a combination of Cenozoic tectonic stability and extremely limited Pleistocene glacial erosion has allowed the preservation of deep-weathering covers of probable Miocene to early Pleistocene age on a scale not previously reported from any other formerly glaciated area.