Field Guide to the Geology of North Norfolk
West Runton - East Runton
Parking: car parks at both gaps; cafe and toilets at West Runton beach, amenities in East Runton. The proprietor makes a small charge in the except in winter. Pay at the Cafe if there is no attendant.
Access: from East Runton gap (TG 201428) or West Runton gap (TG 185432). Guided Geology Walks are available in 2011 from February to October.
This classic section and Site of Special Scientific Interest is used frequently for teaching.
This is a good sign for fossil collectors. A stormy day and a high tide should clean up the West Runton Freshwater Bed nicely, freshly exposing another crop of fossils.
The West Runton Freshwater Bed
For 300m to the east of Woman Hythe (West Runton Gap) is the main outcrop of the type deposit of the Cromerian warm stage, the West Runton Freshwater Bed. It forms a prominent dark bed at the base of the cliff up to a maximum of 2m thick. It is highly fossiliferous and rich in the remains of plants and trees (seeds, cones, wood, fungi and pollen), molluscs (terrestrial and aquatic shells), fish (scales, teeth and bones), amphibians, large and small mammals (bones and teeth) and birds (bones). The WRFB spans the late Beestonian cold stage to the mid-Cromerian warm stage. Wanton digging is unproductive. Sieving and careful searching are recommended. Remember, this is a scientifically crucial site. Please help to conserve it and report any interesting finds to the Norfolk Museums and Archaeology Service (Cromer Museum 01263 513543 or Norwich Castle Museum and Art Gallery 01603 493625).
This is the site of a famous fossil find - the West Runton elephant (now called the West Runton Mammoth) Mammuthus trogontherii. A new monograph has been published by Elsevier Quaternary International, 228 (2010), consisting of a collection of papers by the many scientists who worked on the West Runton elephant excavation. I reproduce here, the faunal list for the West Runton Freshwater Bed, as listed by Stuart
Stuart, A.J. and Lister, A.M. , 2010. The West Runton Freshwater Bed and the West Runton Mammoth: Summary and conclusions. Quaternary International, 228 (2010). Elsevier 241-248.
You can still buy copies of the original publication on the West Runton Elephant, but hurry, stocks won't last! The West Runton Elephant Discovery And Excavation by A. J. Stuart £ 4.50 ISBN: 0 903101 64 5 This is the story of the discovery and excavation of a most spectacular fossil elephant skeleton, the oldest and largest ever to have been found in Britain. (paperback 12 pages)
Weybourne Crag is an old term, used to describe mainly shallow marine facies, with sands, gravels and silts and clays that cover a long period of time through the Pre-Pastonian cold stage, the Pastonian warm stage and the Beestonian cold stage. These sediments are nowadays called the Wroxham Crag and underlie the West Runton Freshwater Bed.
Directly on the top of the Chalk is the Cromer Stone Bed and then the Weybourne Crag, which are often well cemented by iron pan and calcrete. When the West Runton eastern beach is heavily scoured by the tide, the exposed beds of Pastonian sands and gravels show strong saucer-shaped basins a few metres across and fossil ice-wedge casts, which may be attributed to the subsequent Beestonian cold stage.
Shelly sands, grey silts (when un-oxidised) and grey conglomerates of the Weybourne Crag (above) outcrop on the foreshore under Wood Hill and towards East Runton Gap and are attributed by West (1980) to the Pastonian and Pre-Pastonian stages. They have produced a fauna including voles, shrews, giant beaver, deer, elephant etc. This fauna is significantly older and more primitive than the succeeding Cromerian fauna of the West Runton Freshwater Bed.
Chalk, paramoudras and flint circles
The Paramoudra Chalk is only exposed at low water and the amount showing in these images is exceptional. Often much of the foreshore is covered by sand. In parts, the upper few centimetres of the Chalk on the shore platform are brecciated (broken in situ) due to subaerial periglacial conditions in the Lower Pleistocene, before the Cromer Stone Bed (Pre-Pa Ia) of the earliest Wroxham Crag were laid down on top of the Chalk.
On the low foreshore there are paramoudra flints (pot stones) and the related flint circles (occasionally double flint circles). These are trace fossils of an unknown creature inferred to be a worm-like thing named Bathychnis paramoudrae. Where a flint band outcrops across the beach (due to the easterly dip of the chalk) some of the flints are paramoudras that are are spaced 1 to 3 meters apart.
The 900m cliff section under Wood Hill has some of the most spectacular glaciotectonics in Europe. Rafts of Chalk, hundreds of metres long, have been thrusted and folded by ice moving from the north north west, raised up to 40m above beach level and incorporated within the Contorted Drift. In places some of the Weybourne Crag is carried on the Chalk rafts too.
To the west of Wood Hill is a large sand basin, which extends from the clifftop down almost down to the pre-glacial beds. There are also smaller basins and pods, incorporated in the Contorted Drift. Close to East Runton sea wall is a channel or basin of coarse boulder gravel at the top of the Contorted Drift. This is interpreted as a pro-glacial thrust stack.
Almost the whole section is underlain by the Cromer Forest-bed at the base of the cliff, and the fossiliferous Wroxham Crag below that on the foreshore (see the photo above).
Explore my Photosynths of the Wood Hill glaciotectonics:
This is best viewed full screen. Click on the full screen icon when it is up and running. Click Escape to come back to this point.
A second sequence, after a hard winter's frosts.
Sharman Cutler's Stone
Opposite a point between Goss' Gap and Wood Hill lies a large round-backed stone (TG193432). It only appears at low water, on spring tides, half buried in the sand. Made of a hard crystalline rock it is evidently very resistant to erosion, for on its seaward side are some carved initials and a date. It says 'SC 1770' or maybe it is 1773, it is hard to tell.
Alfred Savin, in his History of Cromer (1936), mentions this stone and tells us:
"An interesting fact was recently brought to my notice by my friend, Mr. Vial Abbs. At West Runton, opposite the Chine in the cliff, which conveys the stream of water from the Brick Yard, and cuts through the well known Upper Freshwater Bed, is a large Glacial boulder of Granite, 100 yards from the cliff.
"Mr. Abbs' father (born 1815) when a boy was shown this stone by his father. It was then at the foot of the cliff, and had the following initials and date cut in its face : 'S.CUTLER, 1770." S[h]arman Cutler was a builder at Runton and Cromer (on Poor Rate 1767). It is a large stone some 5 feet in length and about 3 feet high. and lies on hard sand; The inscription is on the sea side. Its greatest value is showing the rate of coast erosion. Many Geologists have tried to calculate this and they vary from one yard to three yards per year for all the Norfolk coast."
I measured the distance from the stone to the base of the cliff on 8 February 2011 and found it to be 146m. Dividing the distance by the apparent time elapsed gives an average rate of erosion since the 18th century at 0.61m per annum. This does not accord with Savin, nor the evidence from historic maps, which indicate a rate of only 22 cm of erosion per annum over the last couple of centuries. Evidently, either the stone has moved, or it was not actually at the bottom of the cliff when it was carved! I favour the former.
St. George's Rock (or 'Black Meg'?)
Closer to East Runton Gap, a short distance (about 250m from the cliff base) offshore from Wood Hill (TG198431) there lie some rectangular blocks heaped upon one another. On the Ordnance Survey First Edition 1838 they are named Black Meg but in modern times I have heard them refered to as (St.) George's Rock. Only exposed at low water, they are a favourite perch for cormorants. When viewed up close, they are clearly of dressed stone, covered in weed and barnacles. One supposes that they were once cargo in the hold of a wooden ship and destined for some coastal civil engineering project, perhaps a harbour, when she foundered on the lee shore at Runton. The ship would have quickly broken up (witness the Agenoria shipwrecked at Cromer in 1868) and now she has disappeared altogether, leaving her cargo stacked almost as it was in her hold. All this is supposition. If anyone knows the story of these rocks, would they please get in touch.
Compiled by Martin Warren. Last updated 15.1.2011