Age (Quaternary period, 400,000 to 10,000 years ago), whichoverlie all the older rocks mentioned above.

This leaflet is about aggregates - sand and gravel - which wereobtained from these desert rocks and Ice-age deposits and weremuch needed for roads or concrete and mortar in theconstruction and building of the expanding Black Countryconurbation.

Scorching desertsThe desert phase began in the late Carboniferous period and isrepresented in Sandwell by two groups of rocks known as theKeeleand Envilleformations, now sometimes grouped togetheras the Salop Formation by some authors. The change inenvironment was brought about by earth movements associatedwith the coming together of the earth’s landmasses to form onesupercontinent known as Pangaea around 300 million years ago.This caused repeated mountain building, erosion and creation ofrift valleys with volcanic activity in places. It was at this time thatthe local dolerite, the Rowley Rag, was intruded into the coalmeasures forming the Rowley Hills.

The Keele formation comprises mainly mudstones with somesandstones, all predominantly purple-red in colour formed undertemporary, probably seasonal lakes in a wide desert basin. Theformation extends from north of Causeway Green up to themotorway at Grove Vale. It underlies West Bromwich and thewestern half of Sandwell valley where small outcrops occur. Thebest outcrop can be seen, when travelling on the Metro, in therailway cutting immediately north of West Bromwich station (1).

The Enville formation is very similar to the preceding Keele butsandstones predominate. The formation extends from Brandhallthrough West Smethwick and the Hawthorns almost as far asSandwell Priory although exposures are small and mainlyconfined to old sand pits. Near Hampstead, sandstones withfootprints of amphibians or reptiles as well as plants werediscovered but these locations have now been lost.

A distinguishing feature of the Enville Formation is the sporadicoccurrence of thick bands of pebbles cemented together calledconglomerates which were exploited for gravel. The constituentpebbles comprise a mixture of limestone, chert, quartzites,sandstones and volcanic material bound together. These“calcareous” conglomerates are believed to have originated asgravel fans brought down to the desert basin from distanthighlands by seasonal flash floods. They form conspicuoussurface features giving rise to the higher ground at Bristnall Fieldsand Barnford Hill near Oldbury. One of the best exposures of theconglomerates can be seen in the rim of the old gravel quarry onthe far western side of Barnford Hill Park (2).

The early Permian Period, is represented in Sandwell by theClentFormation, which originated as rock debris washed downthe mountains and deposited as scree fans on the desert plain.

Hidden landscapes of SandwellRelative to its size, the Black Country has the most diversegeology of anywhere in the world. From the rocks has comeenormous mineral wealth, including coal, ironstone, limestone,fireclay, brickclay and roadstone all of which are revered today aspart of our mining and social heritage. The geology was the basisof the industrial revolution and the reason why Sandwell and theother boroughs became centres of industry and enterprise.

Rocks from four major geological periods are present inSandwell (Carboniferous, Permian, Triassic and Quaternary). Therocks are nature’s legacy providing a record and the hardevidence from which we learn about the environments andclimates of the past. Fossils, of animals and plants, found in therocks are the memorials of prehistoric life and their ecosystems.

Although the record of the rocks is nowhere complete, the layersof different rocks found in Sandwell, like the pages in a book,reveal a story of tropical swamps and forests, earthquakes andvolcanoes, scorching deserts, and icy wastes.

Geologically speaking, Sandwell is divided into two parts by agreat fracture known as the Eastern Boundary Fault, whichdisplaces the rocks either side of it by hundreds of metres.

To the west of the fault lies the Black Country Coal-fieldcomprising rocks known as The Coal Measures, deposited in thelush tropical forests and swamps of the Carboniferous Periodabout 318 million years ago when Sandwell lay towards thesouthern margin of a vast tropical river delta system near thepresent day equator.

To the east of the fault, the rocks are all much younger, recordinga very long desert phase ranging from late Carboniferousformations (about 300 million years ago) to formations belongingto the Sherwood sandstone group of the early Triassic Period(220 million years ago).

Much of Sandwell, particularly the central and northern parts, areblanketed by glacial sands, gravels and sandy clays from the Ice-

The main outcrop lies south of Brandhall Golf Course betweenthe motorway and the Wolverhampton road but unfortunately itspresence today is only indicated by the characteristic smallangular pebbles, which are mostly red stained, seen in the soil.

The Kidderminsterand WildmoorFormations of early Triassicage complete the story of scorching deserts. The rocks of theKidderminster formation outcrop from Warley Woods toSmethwick and in the area around junction 7 at Great Barr. TheFormation comprises pebbly sandstones and cross-beddedsandstones with thin mudstones but is very much characterisedby the presence of large, well rounded, hard, pink-grey quartzitepebbles which in places form thick conglomerate bands. Thesmooth well rounded condition of the pebbles indicates that theyhave been transported 100’s miles (from the area which is nowNorthern France) by rivers swollen by seasonal rainfall in thedistant mountains.

Scorching desertsand icy wastesDiscovering hidden landscapes of Sandwell

Kidderminster conglomerate, Warley Woods Kidderminster conglomerate, Warley Woods Barnford Hill Park Barnford Hill Park

The Geological CodeThe rocks and landscapes around us contain clues tothe ancient past of the planet, long before man walkedthe Earth. Rock faces, whether in quarries, at theroadside or canalside or in other places are where wecan access this ancient past. Just like sites for wildlifethese can be damaged and destroyed by carelessactions. So when visiting a special geological site:

• Obey the countryside codewww.countrysideaccess.gov.uk

• Stay on footpaths and never closely approach a rockface.

• Leaders of visiting parties must familiarise themselves with the current state of the exposures, carry out any risk assessment that is required by their organisation and plan their visit accordingly.

For more information contact Dudley Museum & Art Gallery 01384 815575

Please follow this geological code to ensure that ourfragile geological sites are protected and used wisely.

More informationIf you’ve enjoyed this leaflet and would like to find out moreabout rocks and fossils then visit these local museums.There’s something to appeal to children and adults.

1. Dudley Museum & Art Gallery, St James’s Road Dudley Tel 01384 81557510am - 4pm daily except Sundays and Bank holidays

2. Lapworth Museum, University of Birmingham, Edgbaston, Birmingham B15 2TT Tel 0121 414 7294Mon - Fri 9am - 5pm, Sat & Sun 2 - 5pmwww.lapworth.bham.ac.uk

3. Think Tank, The Birmingham Science Museum Millennium Point, Curzon Street, Birmingham B4 7XG10am - 5pm daily except 24 -26 Decemberhttp://www.thinktank.ac

Local groupsThe Black Country Geological Society meets monthly. Theprogramme includes field visits and interesting talks. Forfurther information contact Dudley Museum or go on-linewww.bcgs.info

Acknowledgements Cover illustration: Ice sheet meltwaters: copyright RichardWaller; Sandwell during the Ice-age copyright: Nick Arber, Norfolk Museums &Archaeology Service; Sandwell during the desert phase: copyright Neil Turner,Wollaton Hall, Nottingham; contorted bedding: Lapworth Museum, University ofBirmingham

Neither Sandwell Council nor any of its employees, nor the Black CountryGeological Society, nor the Wildlife Trust for Birmingham & The Black Countryaccept any responsibility for any loss or injury, howsoever caused, to anyonevisiting any of the sites mentioned in this leaflet

Enville conglomerate, Brandhall Enville conglomerate, Brandhall

The Kidderminster formation was worked in gravel pits and quarriesin the high ground around Warley Park (3) but all that can be seentoday are abundant quartzite pebbles in the ground surface on someof the paths or along the roadside in Harborne road. Numerous otherquarries were located north of Thimblemill Brook and intoSmethwick. The Kidderminster formation was an important localsource of building sand and gravel. The pebbles were also crushedfor road dressing.

The Wildmoor Formation, which outcrops from Lightwoods Park,Bearwood to Soho, was deposited as sand and silt in a broad,seasonally active river system with a general flow from the South toNorth as far as present day Cheshire. It contains virtually no pebblesand occasional mudstone bands probably representing wind blowndust accumulated under temporary lakes. Owing to an extensivecover of glacial material the Wildmoor sandstone was not workedlocally but elsewhere it was an important source of sharp sand andwhere it contained clay particles and the quality was good enough itwas also used as a moulding sand for the foundry industry.

Life in the desertsFor 80 million years Sandwell lay within or on the edge of a greattropical desert. It was hot, dry and windswept though not completelyrainless and at times subject to seasonal flooding from torrentswhich swept sand and gravels from mountains near and far.

Some of the lake sediments have yielded fossils of small shellfish orprimitive worms. Rare footprints of several different species of eitheramphibians or early reptiles have been preserved in the hardenedmud but generally land animals had poor chances of fossilisation insuch conditions. Plant fossils have been found in the EnvilleFormation near Hamstead. The skull of an amphibian was found inthe Enville Formation near Kenilworth, indicating that despite theharsh conditions some animals managed to eke out an existence.

Fossil scorpions and a fragmentary fish fossil is known from theWildmoor Formation near Bromsgrove.

Icy wastesThe larger part of Sandwell is blanketed by extensive superficialdeposits (drift) of sands and gravels which overlie all the other olderbedrock formations. Only the higher ground between Brandhall andWarley Woods and an isolated area either side of the motorway inSandwell Park are largely drift free. Most of the Ice Age deposits areclassified either as Till (boulder clay) or Glaciofluvial sands andgravels.

Till is mainly an unsorted mix of clay with pebbles and boulderstransported by ice and left behind when the ice melts and retreats.The larger boulders are known as erratics because they occurrandomly and in many cases have been transported hundreds ofmiles and have no relation to the local rock types.

Glaciofluvial sands and gravels were deposited by meltwaterstreams. Sometimes the streams would have been under or within

the ice sheets or glaciers. In other cases they are the product ofoutwash flooding during the seasonal thaw and form sheetlikespreads or river terrace deposits away from the ice front.

The Ice Age, technically known as the Quaternary period, was notjust one episode of severe glacial climatic conditions but severaloscillations from cold glacial to warm interglacial. Over the last 2.5million years of the Quaternary period there have been at least 21glacial stages interspersed by warmer conditions similar to orwarmer than today.

Most of the Sandwell Ice Age deposits are believed to date from theAnglian stage (about 400,000 years ago) which, at its height, wasthe most severe glacial episode in Britain and 1km thick Ice sheetsreached the outskirts of London.

The Ice sheets of the last phase of glaciation, the Devensian stage,reached as far south as Wolverhampton. This stage peaked ataround 20,000 years ago with the ice finally departing only 10,000years ago. So some till and sands and gravels may be of this age.

From an economic standpoint the Glaciofluvial deposits have beenthe most important source locally for sand and gravel and may yethave future potential. In places the thickness of cover isconsiderable, filling up deep channels in the underlying bed rock.

The area around Smethwick and West Bromwich once had a greatmany small scale pits working the thick plateau of glaciofluvial sandsand gravels which can sometimes be seen in the canal cuttings inGalton Valley.

The maximum thickness is found in the north of the borough wherethe workings were much more extensive. The sand pits at StoneCross, Bustlehome (4) and Newton/Grove Vale (5) exploited theMillfield Channel (also known as the proto Tame channel) where thethickness of drift reached 19m. The deposits at Stone Cross andBustlehome were remarkable for the contorted bedding, the foldingof which is believed to have been caused by an overriding ice-sheet.Today only glimpses of the deposits can be seen around these pits,in the ground surface and around the roots of trees. Someexposures occur in the adjacent canal banks.

From suitable vantage points the breadth of the relatively flatbottomed valley of the river Tame can be appreciated. The river hasin former times been considerably bigger and more powerful. Riverterrace deposits, believed to be associated with the later Devensianstage but probably derived from older glaciofluvial deposits, blanketthe bottom of the valley. During the last 10,000 years alluvium hasbeen accumulating along the floodplain consisting of about 2 metresof brown sandy clay and is well exposed on top of the terracedeposits in the west bank of the Tame near Tanhouse Avenue (6).

Life in the icy wastesIn areas south of the ice-sheets, tundra conditions existedsupporting a fauna which included Mammoth, Woolly Rhinoceras,Musk Ox, Reindeer and Giant Elk. Conditions would have beensimilar to those in the northern parts of Canada or Russia today.Fossils, usually teeth, antlers or jaw bones, were often found byquarrymen in and around the Black Country.

Fossils from the warm interglacial episodes include Elephant andHippopotamus, related to modern African species. At these timesthe English Channel had not fully formed and there was still a landbridge to the continent.

Human occupation of Britain occurred in phases linked to theadvance and retreat of the ice sheets. Evidence from further afieldsuggests that, except in the most severe climatic conditions,Neanderthal peoples were living in the midlands during the Anglianstage and the following interglacial. They appear to have departedsubsequently reappearing in the interglacial preceding the Devensianstage. About 35,000 years ago modern humans made their firstappearance in southern England and not long afterwards theNeanderthals died out. The onset of severe glacial conditions,peaking around 20,000 years ago saw human departure again withLate Upper Palaeolithic people returning around 13,000 years ago.

Published by Sandwell Council and The Black Country Geological Society. Designed by David Cole and produced by Whitecroft Designs Limited. This map is based upon Ordnance Survey material with the permission of Ordnance Survey on behalf of the Controller of Her Majesty's Stationery Office © Crown copyright. Unauthorised reproduction infringes Crown Copyright and may lead to prosecution or civil proceedings. Sandwell MBC Licence No100032119 2009 4th March 2009. Geological map based upon BGS Sheets 167/168 with the permission of the British Geological Survey, IPR/99-51C.

KEY

Alluvium

Glaciofluvialsand and gravel

Wildmoor fm

Kidderminster fm

Clent fm

Enville fmconglomerates

Keele fm

Coal measuresand Etruria Marl

Dolerite

Scorching desertsScorching deserts

Sandwell during the ice ageSandwell during the ice age

Tipton

CM/EM

CM

D

Ke

Cle

En

D

Cle

En

Ke

Kdm

Kdm

WmS

WmS

Wednesbury

Qua

tern

ary

Per

mia

nTr

iass

icC

arb

onife

rous

Eastern Boundary Fault

EasternBoundary Fault

56

4

3

2

1

Newton

GreatBarr

WestBromwich

SandwellValley

WarleyWoods

Smethwick

Blackheath

Oldbury

Cradley Heath

Contorted glacial sands at BustlehomeContorted glacial sands at Bustlehome

Glacial gravels, Stone CrossGlacial gravels, Stone Cross Dark brown alluvium on red sandy gravel, River Tame, NewtonDark brown alluvium on red sandy gravel, River Tame, Newton

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Simplified geological map of Sandwell

M

il l f ie ld Channel