glacial stratigraphy

ice age events

Significance: thick sequences of glacial deposits on the border of East and Mid Lothian

Red Scar (NT 438631) and East Water (NT 437623) are river bank section lying within the meltwater channel system of the Keith Water. Both sites were described by JAT Young in 1966 at a time where exposure of these deposits was probably rather better than at present.

Red Scar is a 30 m face in the Keith Water of which the lower third was vegetated. The sequence shows:

1. More than 15 m of dark brown sand resting on
2. 4 m of red brown till with fragments of coal, Carboniferous sandstone and greywacke on
3. 4m  of pale brown sand
4. 10 m of very dark grey till with fragments of Carboniferous sandstone, and greywacke, limestone and coal

Nearby a section in the valley side of the East Water shows:

1. 1 m dark brown sand with Holocene soil.
2. 1.5 m, dark red Brown till with fragments of call, Carboniferous sandstone and greywacke.
3. 0.6 m pebbly sand
4. More than 4 m and dark brown till with fragments of coal, Carboniferous sandstone, greywacke and tuff
5. 1 m current bedded sands with coal fragments
6. More than 3 m, dark grey till with fragments of call, Carboniferous sandstone, greywacke it and limestone.

Young concluded that the local stratigraphy showed an initial movement of ice from the southern uplands, and a later movement across part of the Midlothian basin. Till fabric analyses showed that the tills were mainly lodgement tills but the fabrics revealed no clear differences between successive units, probably a reflection of deposition with pre-existing and deep valleys. The numerous sand layers point to ponding of meltwater as ice margins fluctuated.