Hull Geological Society

Erratics – the silent sentinels of Holderness.

What the ice age did for Holderness.

Written by Stuart Jones FGS, Hull Geological Society.

Printed and published by R S Jones FGS, Kingston upon Hull.

First published 2011.  Copyright RS Jones 2011.

Edited and republished by Mike Horne FGS, Hull Geological Society 2026

Front cover: the Tesco Erratic, Southgate, Hornsea.

Introduction.

Walk along a beach in Holderness, say Barmston, Skipsea, Hornsea, Mappleton or Aldborough and before long you will come across some boulders of many shapes and sizes.  Look a little closer and it will be seen that they are not all made of the same material.

There are some of limestone, some are of granite, basalt or quartzite and many other different kinds of rock but most of them will have one thing in common.  Look very closely and at least one side or face will bear a series of parallel lines or grooves scratched into its surface.

This is a true sign that what you are observing is an object known to geologists as an ‘erratic’ of glacial origin.  These rocks have been transported to this place by being trapped and frozen into the ice at the bottom of a glacier during the ice age.  The grooves or striations are made by contact with other stones and rocks over which the ice passed as it gradually spread over the landscape.

What is not readily apparent is that these erratics are not only to be found on the beaches where they have been washed out of the cliffs by the sea’s constant erosion, but are also found inland.  Maybe they are not so obvious as a good many have been used for building material but the very large ones still survive and can be found in the most unlikely of locations where they sit keeping their solitary watch down the passing centuries.  This is their story.

At the end of the last period of glaciations the landscape in the Holderness area and the surrounding parts of the Yorkshire had taken on a somewhat different appearance to that which had been in existence before the ice had engulfed it.  Much of the original topsoil had been scoured away and subsoil together with the quantities of rock debris have been torn loose and brought up to what is now the new surface level.

Some of this material included very large boulders and of these there were some that have been carried many miles from their place of origin by the ice as it advanced across the landscape.

A large number of these rocks were crushed and broken into smaller pieces and became buried and together with the finer deposits of mud, silt etc.  They became part of the Boulder Clay of which most of Holderness is formed, but a fairly significant quantity remained on or close to the surface of the land.

As the years had passed by some of these rocks sank under their own weight into the soil or clay upon which they have been deposited as the ice cover melted and receded and yet others of their kind remained at the surface level in places where the soil and subsoil was of insufficient depth to allow them to become covered and survey remained visible covered only by a thin cover of moss or lichens.

Our story concerns some of these rocks that survived in today’s world in the locality of the town of Hornsea on the coast of Holderness in the East Riding of Yorkshire.

Enquiries made amongst the older citizens of this mini metropolis have produced the information that in times past there were no less than four of these large erratic boulders - one at each end of the four roads which enter the town and these were regarded as ‘way markers’ or boundary stones.

Unfortunately only one of these rocks has survived into the 21^st century more or less in the same place as it had always been, on Southgate roundabout opposite the fire station and near what was once a petrol station.

Adjacent to this site is the new ‘Tesco’ building currently under construction and the contractors have kindly undertaken to see that a place is made to display this last remaining artefact at the entrance to the store car park.

Another of the stones that was known to the author in the early 1960s was at a place on Atwick Road (at the north entrance to the town).  Their location is what is now the entrance to College Gardens - a housing development which in the 1960s was a farmer’s field used to store small fishing boats in the winter time when not in use.

The centuries and ages passed and in the fullness of time new vegetation developed to clothe the barren landscape and gradually the land became populated and an early form of cultivation began to develop.  As this proceeded these great pieces of rocks (or some of them) came to the notice of the people who worked the land etc.

At this point in history some villages and even what passed for small towns have sprung up in places where some of these rocks were in evidence.  At first these early boulders etc.  were content to lay where they have been deposited many centuries before and where they still lay – indeed in some cases moving them would have proved impossible given the limited equipment and tools at their disposal.

Also it is a fact that some of these ‘erratics’ - to give them the correct name, have proved to be so hard that they would have easily defied the efforts of men with recourse only to basic and towards and even the types of explosives available to the early engineers of the 15^th century onwards.  Therefore they stayed where they were patiently waiting as the centuries have passed them by until man had invented devices capable of moving such objects.

By this time some of these rocks have become surrounded by towns and indeed they can still be seen to this day in quiet corners where the people have become quite used to their presence and they are as familiar as lamp posts or pillar boxes - a sort of natural street furniture.

The cliffs at Aldborough.

 Showing some of the larger boulders that have recently been eroded out of the cliffs by the action of the sea, and one is visible just emerging halfway up the cliff (centre of picture).

  [Editor's note - the images are digital photographs of the original 2017 printed publication.]

Links -  Stuart Jones obituary

Copyright - Hull Geological Society 2026

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