Welcome to the Ice Age Coast

These are not Glacial Erratics

(mostly from the Holderness Coast)


Aluminium - from used ordinance

armoured mud ball

Armoured mud balls - boulders of boulder clay with attached pebbles

Asbestos as an erratic








Asbestos - from roofs

Augen Gneiss rock armour

Augen gneiss - imported from Scandinavia as "Rock Armour"

Bones and teeth - of animals buried by farmers in their fields

Brick - brick red normally. May have what appear to be borings!

China crockery - comes with many designs including the mock Chinese"willow pattern"

chocolate diegstive as an erratic

Chocolate covered digestive biscuits - seen at an exposure of Basement Till at Bridlington in 2019

Coal - it may have fallen off a boat in the past or be "sea coal". Often you can find patches of small black grains of coal gathered in a sand ripple on the beach.

calcrete boulder at Flamborough beach

Calcrete - a natural concrete formed by the percolation of hard water through sediment.

concrete boulder

Concrete - grey. May be reinforced with steel rods. May be large structures from WW II such as tank traps and pill boxes. May be coloured red or yellow when used as paving stones.

NRS found at Withernsea

Dimension Stone - used for buildings such as this piece of carved New Red Sandstone.

double yellow lines erratic

Double yellow lines - No Parking on the beach!

gneiss at Mappleton 

Folded gneiss - large boulders from Scandinavia used as Rock Armour

Glass (or "sea glass" naturally frosted) - from broken bottles

Graptolites - these are fakes drawn on Welsh slate with a pencil

Green glassy slag - hard, may be vesicular (containing bubbles), about 30mm across; mistaken for "meteorites". Origin - imported from Scandinavia and gets everywhere.

Iron - wartime defenses or car parts.

land drain

Land drains - unglazed terra cotta pipes and "U" shaped channels

Larvikite - imported from Norway as "Rock Armour", (note also occurs a natural glacial erratic)

Marble - white Cararra Marble from Italy used as worktops or slabs for rolling pastry

Oolitic Limestone - probably from the Middle Jurassic of Vale of Pickering used as "Rock Armour"

Pegmatite - imported from Scandinavia as "Rock Armour"

plastic erratic

Plastics - get everywhere (seen here attached to rusting iron)

Sewerage pipe - often grey inside with a brown glaze

Slate - dark grey Welsh slate, used as a roofing material

Tarmac - a grey breccia with a black matrix



(c) Mike Horne & Hull Geological Society 2020

Copyright Hull Geological Society.