The Geology of Britain

Peter Toghill (2000) Crowood Press

This was the book which started it all off for me. I read this book back in 2005 and all the references to diagrams from S236 Historical Geography from the Open University sent me straight through their (virtual!) doors. This book suffers from the same problem as a lot of geology books in that it sometimes reads like a shopping list. That aside it is a good overview of British geology.

 

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The Castleton Area, Derbyshire

Trevor D Ford (1996) Geologist's Association Guide

The ultimate in depth guide to Castleton with 4 itineries.

 

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Ancient Peakland

Bill Bevan (2007) Halsgrove

A get out and see guide to Peak archaeology.

Ice age hunters - 50,000-10,000 years ago

Creswell Crags

Thor's Cave

Forest Nomads - Mesolithic 10,000-6,000 years ago

First Farmers - Neolithic 6,000-4,000 years ago

Pea Low

Long Low

Five Wells

Arbor Low

Bull Ring

Dead Ringers - Neolithic to early Bronze Age 4,500-3,500 years ago

Stanton Moor, nine ladies and others

Robin Hood's Stride and nine stone close

Seven stones of Hordron

Froggatt edge stone circle

Wigber Low

Barbrook 1 and 2

Hob Hurst's House

Wet Withens

Pike Low burial mound

Beeley Moor triple cairn

Settling Down - Later Bronze Age to Iron Age 3,500-2,000 years ago

Mam Tor

Gardom's Edge

Castle Naze

Big Moor - Swine Sty

Carl Wark

Mellor

Romans and Natives - 43AD-400AD

Navio

Ardotalia

Chee Tor

Roystone Grange

North Lees

Poole's Cavern

Illuminating the Dark Ages - 400AD-1066AD

Grey ditch

Hope

Eyam

Benty grange Anglo Saxon burial

Alstonfield and Ilam

Bakewell crosses

Bradbourne church and cross

 

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The geology of Eyam

John S Beck (self published)

This slim pamphlet is available in the Eyam museum. It contains a (very!) brief introduction to the geology and 3 geology walks in the Eyam area.

 

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Castleton caves

Trevor D Ford (2008) Landmark Collectors Library

While the introduction of this book indicates that it is of interest to the general public as well as cavers, it would definitely be more interesting to the latter. It contains maps of the caves which would be useful to a caver but otherwise it contains a lot of tedious descriptions of the cave systems.

1. The Castleton Karst

2. Cave Exploration

3. Peak Cavern

4. The Speedwell Mine And Cavern

5. Leviathan And Titan

6. The Blue John Cavern

7. Treak Cliff Cavern

8. The Rushup Edge Swallets & Nearby Caves

9. Giants Hole

10. Windy Knoll Cave

11. Mam Tor Swallet

12. Caves In The Winnats Pass

13. Odin Mine

14. Rowter Hole

15. Longcliffe Mine And Pot

16a. Eldon Hole

16b. Thistle Pot

17. Oxlow Caverns

18. Nettle Pot

19. Lost Caverns

20. Hydrology

21. Speleogenesis - The Evolution Of A Cave System

22. Future Possibilities For Exploration

 

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Lead mining in the Peak District (4th edition)

T.D. Ford & J.H. Rieuwerts (2000) Landmark Publishing

Introduction: Geology

The common ores mined in the Peak District are GALENA (lead sulphide), SPHALERITE (zinc sulphide), FLUORITE (calcium fluoride), BARYTE (barium sulphate) and CALCITE (calcium carbonate).

RAKES are major veins formed in vertical fissures often 2-3 m wide but up to 15 m wide. They can be 4-5 km long and some have been mined to 200 m deep.

SCRINS are smaller versions of rakes not often more than 50 cm across and 1 km long.

FLATS are horizontal deposits laying parallel to the bedding.

PIPES are irregular deposits parallel to the bedding.

Pipes and flats are often close to or capped by thin volcanic deposits know as wayboards.

The mineral deposits were formed from hot fluids which came from 2-3 km below the surface and picked up minerals on the way. These were precipitated by cooling, mixing with cooler surface waters, reaction with sulphur compounds in pore waters or reaction with oxygen in such waters. This reached a climax at the end of the Carboniferous 270 million years ago.

Galena (PbS) is easily recognised by its silvery metallic lustre. Veins contained form as much as 10% to as little as 2%. The veins along the eastern margin of the mineral field also contained sphalerite (ZnS) recognised by its dark brown chocolate colour and also known as blende or blackjack. It had little value until brass (an alloy of zinc and copper) became popular in Victorian times. In a few areas the sulphides have been oxidised to carbonates, cerussite (lead carbonate) and smithsonite (zinc carbonate, commonly known as calamine). Cerussite is the raw material for white lead and several White Rakes are allegedly named after it. The gangue minerals of metal extraction were fluorspar, barytes and calcite. Nowadays these are the main products and metallic ores are byproducts. Fluorspar (CaF) is the chief source of fluorine for the chemical industry. It is largely confined to a 2 km wide strip at the eastern margin of the ore field. Baryte (BaSO4) and calcite (CaCO3) complete the 5 minerals which form the bulk of the mining activity in the Peak District.

This is followed by a comprehensive history of mining in the Peak District and then a list of itineries.

Itineraries:

1. Castleton

2. Peak Forest

3. Hucklow, Eyam, & Stoney Middleton Area

4. Sheldon & the Magpie Mine

5. The Ashford Black Marble Mines & Mill

6. The Lathkill Dale Mines

7. Hillocks & Knotlow Mines, Monyash

8. The Alport Mines

9. The Lead Mining Village of Winster

10. The Wensley-Darley Area & Mill Close Mine

11. The Matlock Area

12. Cromford & Bole Hill

13. Good Luck Mine, Middleton-By-Wirksworth

14. Wirksworth

15. Carsington Pasture & Brassington

16. The Crich Area

17. Stonedge Cupola, Ashover

18. The Ecton Copper Mines

 

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The Pennines and adjacent areas (Regional Geology Guides) Fourth Edition

N. Aitkinhead et al. (2002) British Geological Survey
Time to read the definitive guide to the geology of the Peak District and other Pennine regions.
Pre-carboniferous rocks. There are some outcrops of Ordovician and Silurian rocks in the Yorkshire Dales (near Ingleton, Horton-in-Ribblesdale and Malham) but non in the Peak District area. These have been shown to underlie the Peak District in borehole studies.
Dinantian deposits outcrop to the north of this region on the Askrigg block and Craven basin, and to the south as the Derbyshire dome. The Derbyshire dome consists of the Derbyshire and Staffordshire platforms separated by the Widmerpool Gulf. The Derbyshire platform deposits are from the ramp and shelf of the platform but not the slope and basin which outcrop to the south in the Widmerpool Gulf region.
Platform - thickly bedded, pale grey to grey, massive bioclastic limestones (packstones and grainstones), dolomitised limestone and dolomite. Woo Dale Limestones, Bee Dale Limestones and Monsal Dale Limestones.
Ramp - grey to dark grey, thinly bedded bioclastic limestones (packstones) commonly with chert nodules and pale grey micritic limestones forming knoll reefs (mud mounds).
The rocks of Namurian age form the continuous outcrop which forms the Pennines. It divides at the south of Edale to outcrop on either side of the Derbyshire Dome. Course grained to granular, feldspathic sandstones are the dominant characteristic of the Millstone Grit Group. Ashover Grit near Derby and Chatsworth Grit near Leek form the oldest rocks and overlie the Namurian mudstones of the Edale Shale Group (these also contain sandstones but their proto-quartzitic composition distinguishes them from the Millstone Grit Group).
The successions are of a remarkably cyclical nature marked by regular marine transgressions which define the base of each cycle. There are 46 + 3 more recent of these recognised. They were caused by the growth and decay of the Southern Hemisphere ices sheets.
The rocks are mostly formed from mud, silt and sand carried into the Pennine basin by a large river system from mountains in Scananavia and Greenland. The abundance of fresh feldspar show the erosion and rapid transport from granitic source. The sea level changes also controlled delta growth stopping as sea level rose, and starting again as it fell.
The lower Westphalian Coal Measures were laid down in the Pennine basin between the Southern Uplands High and the Wales-Brabant High. They were laid down as a continuous strata but the movements associated with the Variscan Orogeny in the late Carboniferous and early Permian deformed them into gentle folds. Erosion left only those in the downthrown areas intact. The outcrops are to the east and west of the Namurian sandstones and ad not well represented in the Peak District.
Limestone
The Carboniferous limestones of Derbyshire were famous as decorative stones, commonly termed 'marbles' by the trade because of their ability to take a high polish, their varied colours and attractive structure.They included the Ashford Black Marble, Birds Eye Marble. Rosewood Marble, Duke s Red and Muscle Marble. None of these stones are produced today, but they can be seen as decorative inlays in many of the great houses of Derbyshire such as Chatsworth, Hardwick and Bolsover Castle.Today, polished limestones are produced from the Bee Low Limestones at Hopton Wood and Griffeton Wood quarries. Hopton Wood Stone has been used in many major buildings, including the Bank of England and the city halls of Manchester and Sheffield. On a sombre note, the creamy grey, crinoidal Hopton Wood Stone provided the headstones for the graves of tens of thousands of British and Commonwealth troops who fell in the 1st and 2nd World Wars.
Sandstone
The exploitation of the Namurian sandstones in the Peak District also has a long history and all the major sandstones have been quarried for building stone. In the High Peak area sandstones of the Shale Grit (at Kinder Bank), Kinderscout Grit (at Chinley Moor, Ladybower and Hayfield), the Heyden Rock (at Thornseat), Roaches Grit (at Combs, Ridge Hall and Longhill), Chatsworth Grit (at Birch Vale and Buxworth) and the Rough Rock (at Cracken Edge) have all been extensively worked. The most important area of sandstone quarrying in Derbyshire lies farther south and east along the Derwent and Amber valleys and the intervening hillsides, where the Namurian sandstones crop along the valley sides from Hathersage to Belper. Quarries have long worked the Kinderscout Grit at Stokehall quarries),the Asbover Grit (at Darley Dale, Birchover, Duke's, Whatstandwell and Stanton quarries), and the Chatsworth Grit (at Yarncliff, Beeley Moor, Bole Hill, Lumshill and Millstone Edge quarries). The Rough Rock from the Coxbench quarries was used extensively for buildings in Derby.The Stancliff Darley Dale Stone is particularly famous for its durability and quality and has been widely used in towns and cities (for example Derby Cathedral, the Guildhall in Nottingham). The Ashover Grit used in buildings in the village of Kirk Ireton is stained pink by percolation of groundwaters through the former Triassic red-bed cover. The Shale Grit was used for the Kinder Reservoir and ’Stokehall Stone’ from Grindleford for the Howden and Derwent Reservoirs and Sheffield Town Hall.
Lead
Lead sulphide mineralisation (galena. PbS) has been worked in the area from large numbers of veins.There are several hundred named veins and many small, unnamed ones.They are up to several kilometres long, less than 10 m wide, of limited vertical extent and steeply dipping and consist of galena, fluorite, calcite and baryte.The major veins are commonly known as 'rakes', the minor ones as 'scrins'. Fluorspar and baryte have also been worked in more recent years and are now the main economic minerals recovered; no veins are now worked solely for lead. Semi-concordant 'flats' have also been worked as at Masson Hill near Bonsall. A few short, tubular, subhorizontal pipe oreshoots also occur, as at Hubberdale pipe.The mineralisation is largely confined to the eastern half of the exposed Dinantian limestone outcrop and is mainly hosted within the Monsal Dale Limestones, where overlying Namurian shales formed an impermeable caprock to the mineralising solution. The most important deposit was at the Millclose Mine near Darley Dale, where over 400 000 tonnes of lead concentrate and 90 000 tonnes of zinc concentrates were recovered from a remarkable orebody where natural concentration of galena in a cave system produced very high grades of mineralisation. Elsewhere in the orefield, the grades were about 5 per cent Pb, the exact figure dependent on the width of vein worked. Modern exploration has continued to develop the orefield, with the emphasis on fluorspar. In the early 1950s, there was an attempt to further develop the Riber Mine on the Great Rake for lead and zinc. Initial boreholes showed promising widths and is of lead mineralisation. However, subsequent underground development showed that miners had removed much of the mineral and that the boreholes had fortuitously through unworked pillars, giving a false impression of the possible resources left in the vein. The mine was closed in 1958. Calcite production continues from the Long Rake vein in the centre of the orefield.
This is very much just the highlights of the book. I expect I will be returning to this book again and again as the journey continues.

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Geological excursions in the Sheffield region

Various (1967) University of Sheffield

1. The Wye Valley

2. Earl Sterndale Area

3. The Castleton Reef Belt and adjoining areas

4. The Carboniferous Limestone of the Stony Middleton Area

5. The Visean Rocks of the Matlock—Wirksworth—Monyash Area

6. The Ashover Area

7. The Crich Inlier

8. Volcanic Rocks in the Peak District

9. Some Mineral deposits of the Carboniferous Limestone of Derbyshire

10. Fossiliferous localities in the Namurian Rocks of Edale

11. Namurian Sedimentation in the High Peak

12. The Bradfield—Ewden Area

13. The Ashover and Chatsworth Grits in North-East Derbyshire

14. The Namurian and Basal Westphalian Rocks of the Beeley—Holymoorside Area

15. The Namurian and lowermost Westphalian Rocks in the southern part of the Goyt Syncline

16. Westphalian A Palaeontology and Stratigraphy of the Langsett—Penistone Area

17. The City of Sheffield

18. The litho-facies of a Lower Coal Measure Sandstone Unit between Sheffield and Brighouse

19. The Middle and Upper Coal Measures (Westphalian B and C) north-east of Sheffield

20. Conisborough

21. The Permo-Triassic Rocks of the Worksop Area

22. Scunthorpe

23. Kirton, Lincolnshire

24. Nettleton, Lincolnshire

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The Living Landscape

Patrick Whitefield (2009) Permanent Publications

Reading the landscape is at the heart of this blog, not just in the Peak District but everywhere. This book is the book I have been looking for for ages, it brings together all I have learned and more into one volume. As a reminder for myself I made notes as I read it.

The landscape and how to read it

Four landscape forming factors: rocks, soil, climate and living things.

Or two: the natural and the human.

The four factors are constantly interacting. Rocks affect landforms. Landforms affect climate. Rocks and climate affect the soil. Soil and climate affect vegetation. Vegetation affects soil and climate.

Three important themes. Everything changes. Everything’s connected. Everything has multiple causes.

Different timescales: annual, succession, rotational (human controlled).

Rocks: the bones of the landscape

Most fundamental difference is basic v acidic. Basic - alkaline soils rich in plant nutrients, acidic - acid, nutrient poor soils.

Igneous rock: granite, acidic; basalt, basic.

Sedimentary rocks. Sandstone - acidic, nutrient poor soils. Sandy heaths were often common land as they are nutrient poor and often remain as common land now eg Hampstead Heath. Clay - alkaline, nutrient rich soils. Often used as agricultural land. Limestone (including chalk) almost always makes hills as it is so permeable that no erosive surface water remains. Limestone soils are very alkaline but not necessarily rich in other nutrients so not necessarily fertile. Coal measures are the major determinant in urban v rural landscapes.

Hills and valleys

Upfolds don't always form hills (although they can!). Downfolded rocks are compressed and hardened; upfolds are stretched and weakened. These erode away more quickly than the strengthened rocks of the downfold.

Young rivers form V-shaped valleys which twist and turn. Cultivation is on the hills above the valleys. Glaciers form U-shaped straight valleys where the cultivation is in the valley as the hills above are too exposed for cultivation.

The soil and what plants can tell us about it

Fundamental difference is between the well drained, nutrient poor sandy soils and the alkaline, plastic (and as a consequence not well drained) clay. Clay loams are nutrient rich but plastic (heavy) and was often used for wheat and beans. Easily worked sandy loams were used for vegetables (rabbits and bracken clues to sandy soil).

Soil types. Podsol - acid. Excessive drainage washes nutrients from surface to hard pan below. Often forms on granite and sandstone. Characteristic of heaths and moors. Too acid for worms! Brown earth - not too wet, not too dry. Very good for agriculture. Also found in forests and grasslands. Gley - heavy clay soil with high water table which forms a blue/grey layer. Too wet to cultivate so used for meadow or pasture. Too wet for worms! Peat - extreme waterlogging prevents decomposition leading to peat. Peat can often form when heather forms a hard pan on a podsol leading to poor drainage. Rendzina - thin, alkaline soil on limestone.

Plant indicator species. Strong indicators eg reeds always indicate wet soil v communities. Indicators can tell us about water content, acidity, levels of plant nutrients and light/heaviness. Water content: buttercups - moist not wet; rushes - wet most of year; reeds standing water at least part of year; compacted soil has poor drainage and is often wet - plantain can grow on compacted but not wet soil. Acidity: easy at extremes (heather, acid, old man’s beard, alkaline) but look out for exceptions.

Climate and microclimate

Aspect has an effect but not as much as in other countries or as much as the changes in rock/soil type. Altitude has a much greater effect. It is colder (1C per 100m), windier, wetter and cloudier. Frost pockets form in valleys where the cold air flows down from higher ground. Snow can be used to pick out the wind patterns by studying the drifts. Melting snow picks out the warmer and cooler parts of the landscape. Wind flagged trees show prevailing wind (south west) or effects of local landforms.

Heaths and moors

Heaths are usually sandy lowland areas with poor nutrients. Since the advent of fertilisation many of them were turned into agricultural land and they are now uncommon. Moors form on higher ground, usually acidic in nature. Many are semi natural, formed from woodland by grazing. They often follow the pattern of bracken on the slopes and heather or grass moor on the tops (if the slope is too steep heather will take over as the soil is too thin for bracken). Bracken is a very competitive plant but needs more in the way of bases, drainage and deeper soil than other moorland plants. It hates shallow soil, it hates wet feet: where there is shallow soil heather can grow, where it is wet grass and rushes grow. Alternatively gorse may grow on the slope and bracken a the bottom:

There's gold under bracken,

Silver under gorse,

And famine under heather

Moors are usually managed by burning for either grouse or sheep. Trees are more demanding than most heathland plants and often grow by streams where active erosion releases bases allowing them to grow quicker. Blanket bogs form peat where the rainfall is very high and drainage poor resulting in saturated soil. They are natural as they overwhelm the trees whic can't grow in these wet conditions. In the Pennines they often form on the western side at higher altitude, while heather moors form on the eastern side and lower down.

VEGETATION SUMMARY

The Heather Family

Heather or ling. Poor, acid soil, moist to dry, usually a podsol; tolerates thin soil.

Bell heather. Mixed with heather on drier soils, dominant on very dry ones.

Cross-leaved heath. Mixed with heather on wetter soils, dominant where it's too wet for heather.

Bilberry. Often on drier soil or boulders; shade tolerant and often grows in woods.

Plants of More Fertile Soils

Bracken. Deep, well-drained soil, richer and less acid than typical heather soil, usually a brown earth, usually on a slope; can out-compete other plants on a

favourable soil but is sensitive to trampling; altitude limited by cold.

Sweet grasses (bents and fescues). A mix of fine-leaved grasses, usually grazed down short because the animals like them; they grow on similar soils to bracken.

Gorse, common. Slightly poorer soils than bracken but sometimes more alkaline; not cold-tolerant.

Gorse, dwarf and western. Much smaller plants than common gone with similar soil preferences to heather.

Plants of Wet Soils

Matgrass. Similar soil to heather but often a bit wetter; both it and purple moorgrass may take over where heather is overgrazed.

Purple moorgrass. Similar soil to matgrass but usually a bit wetter still; often grows in big tussocks, especially when in a pure stand - very hard going for

walkers.

Bog myrtle. Wet to very wet soil, often with purple moorgrass; like the alder tree, it's a nitrogen-fixer.

Deergrass. Deep peat and bogs, very wet and acid.

Cottongrass. Bogs, even wetter than deergrass and including open water.

Bog moss. The ultimate peat-forming bog plant, only found in extremely wet conditions.

Water in the landscape

Springs form at the junction of permeable and impermeable rock such as limestone and clay. This is often at the boundary of hill and dale. Villages often built near a spring on this boundary with access to grazing and arable land.

Bogs can also form in valleys.

TYPES OF BOG

Blanket. Forms in regions of extremely high rainfall; covers all flat and gently sloping land in a layer of peat. Always acidic.

Valley. Forms in a low place where drainage is impeded, fed by drainage water. Can be acid (bog or moss) or alkaline (fen).

Raised. Forms on top of a valley bog, fed by rainfall. Always acidic.

The rest of the chapters in the book are less relevant to the Peak District or to my particular interests so I have only outlined them here.

The history of the landscape. Very interesting chapter about the farmed history of the landscape including the enclosures.

The three chapters wild animals and how to recognise their signs, niches or how plants and animals make their livings and succession how landscapes change through time are more about ecology than geology.

Woods play a large role in the landscape and there are three chapters are all about them - trees as individuals, the different kinds of woodland and how woods work. Lowland grassland, hedges & other field boundaries, and roads & paths complete the book contents.

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Rocks and Fossils: The Peak District

I.M. Simpson (1982) Unwin Paperbacks

1 Edale and Kinder Scout

2 Castleton Area: Treak Cliff and Mam Tor

3 Castleton Area: Cave Dale and Dirtlow Rake

4 Eyam, High Rake and Coombs Dale

5 Tideswell Dale and Miller's Dale

6 Ashford and Monsal Dale

7 Lathkilldale

8 Youlgreave and Alport

9 Black Rock and Steeple Grange

10 Thorpe Cloud and Lower Dovedale

11 Hartington, Wolfscote Dale and the Tissington Trail

12 Ecton and the Manifold Valley

13 Hen Cloud, The Roaches and The Ramshaw Rocks

14 Parsley Hay, the High Peak and Tissington Trails

15 Goyt's Moss

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Rocky Rambles in the Peak District

Fred Broadhurst (2001) Sigma Leisure

A short introduction to Peak geology is followed by the walks. Nice overview section of the geology.

The walks:

Walk 1: Castleton - Cave Dale - Pin Dale

Limestones, Lava and Lead

Walk 2: Castleton - Lose Hill - Mam Tor

Ridge, Landslip and a Resurrected Sea Floor

Walk 3: Edale - Kinder Scout

Sandstone Scenery, Wind Sculptures

Walk 4: Monsal Dale

Landslips and Fossils

Walk 5: Millstone Edge - Stanage Edge

Millstones and Concretions

Walk 6: Wirksworth

National Stone Centre and Dolomite

Walk 7: Dovedale

Limestone Scenery

Walk 8: The Roaches, Lud's Church

Geology and Scenery

Walk 9: Earl Sterndale - Parkhouse Hill - Chrome Hill

Limestone 'Reefs'

Walk 10: Lyme Park - Cage Hill - Bowstones

Sandstones, Glacial features

Walk 11: Lyme Park - West Parkgate

Glacial Spillway, Fossil Soils and Fossil Ripple marks

Walk 12: Lathkill Dale

Limestones, Fossils and Lead Mines

Walk 13: Goyt's Moss - Shining Tor

Sandstone Scenery and Coal

Walk 14: Ashford-in-the-Water - Magpie Mine

'Black Marble' and Lead

Walk 15: Tegg's Nose

Sandstone and Sandstone Quarries

Walk 16: Tideswell Dale - Miller's Dale

Limestones and Lavas

Walk 17: Rowarth - Cown Edge

Faults, Folds and Landslips

Walk 18: Rowarth - Lantern Pike

Rocks and Topography

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Geology Explained in the Peak District

F. Wolverson Cope (1998). Scarthin Books

This was the first Peak geology book I bought and I found it hard going when I first got into geology (before I started on my OU degree!), so we shall see if it makes more sense now!

Oh dear. After a somewhat superfluous set of introductory chapters this book ploughs on with descriptions of specific areas. It is written for someone with a degree in geology and lacks the idea of a specific itinary which is present in the other 3+ geology walk books available. It is also very old fashioned. Give it a miss.

1 Geology In The Field Field equipment - the Countryside Code - the Peak DistrictNational Park

2 Identifying Rocks, Minerals and Fossils Rocks - minerals - fossils

3 The Geological Time-scale

4 Geological Structure of the Peak District

5 The Valley of the River Wye: Buxton to Little Longstone The Carboniferous basement - the sequence east of Woo Dale - the massif fades

6 The Valley of the River Goyt Millstone Grit and Namurian - pre-Namurian denudation - the Goyt Syncline - Namurian cyclic sedimentation - contorted beds

7 Castleton, Edale and Mam Tor Reef limestones - caves of the Castleton district - the Speedwell Vent - fossils of the reef limestones - the use of goniatites - the Namurian of the Edale valley

8 Bradwell Dale and Eyam Bradwell Dale - Eyam - the Eyam and Woo Dale boreholes

9 Monsal Dale and Ashford-in-the-Water The Hobs House Coral Band - igneous rocks in Monsal Dale - the Ashford marble

10 Matlock, the Via Gellia, and Brassington The Grangemill vents - lead mining in the Peak District - dolomitisation of limestones - Tertiary pocket deposits

11 Ashover Dinantian rocks of Ashover - Namurian rocks of Ashover

12 The Valley of the River Dove Reef limestones of Thorpe Cloud and Bunster

13 Chrome Hill and Parkhouse Hill

14 The Valley of the River Manifold

15 The Roaches and Goldsitch Moss The Rough Rock of Quarnford and Goldsitch - Namurian successions in the Peak District

16 Kinder Scout The Mam Tor Beds - the Shale Grit - the Kinder Scout Grit

17 Economic Geology of the Peak District General and water supply - mining - quarrying

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Rock Trails Peak District

A hillwalker's guide to the geology and scenery

Paul Gannon (2010) Pesda Press Ltd

This is one of several books which contain geology walks. I hope to do some of these next year, maybe combining walks from several books. In this blog entry I will be going through the first 8 chapters which are about the Peak District geology.

Chapter 1 - basement blocks

We start off with a description of the position of the PD at this time, south of the equator and slowly moving north. To the north is a mountain range, and an arc of higher ground to the south (the Wales-Brabant high) from which the Peaks High pokes out. To the north of the Peaks High is the Edale Basin and the the west the Widermerepool Gulf. The area is under extension causing the basins to sink.

Chapter 2 - layers of limestone

Limestone was formed in the shallow seas of the continually sinking basins and on the Peaks High when it went below sea level. Occasionally the sedimentation stopped as the plateau was above sea level (plant roots and soil found between some bedding. This forms the shelf limestone which was a lagoonal environment. At the edge of the shelf are apron reefs which are made from an algal reef and often have fore-reef and back-reef structures. The form a rim around the shelf limestone except in the south west where there is a ramp down to the Widermerepool Gulf. Knoll reefs formed within the main platform and are also known as mud mounds.

Chapter 3 - grains of grit

Sandstone formed by erosion of mountains in north forming deltas into freshwater (and occasionally seawater) in the sinking basin. It is the presence of layers of shale which forms the distinctive step and shelf topography.

Chapter 4 - lingering lignin

Coal was formed in a swampy tropical forest closer inland from the delta lobes. These forests were formed by plants which had a much higher proportion of bark and therefore lignin than modern trees.

Chapter 5 - faulted and folded

At the end of the Carboniferous and into the Permian plates crashed together to the south (finishing the assembly of Pangea). This halted the subsidence and instead the subsided land popped up on existing faults. The harder base of the white peak prevented serious folding resulting in the gentle dome of limestone. Especially to the west much folding took place resulting in many synclines and anticlines. Faults caused by the movement were mineralised by this tectonic activity.

Chapter 6 - drainage delights

Spring lines and landslips.

Chapter 7 - solution and superimposition

Sink holes, caves, dry valleys, stalactites and superimposed drainage.

Chapter 8 - peak and people

Exactly what it says.

The walks:

Walk #1 Kinder Scout

Walk #2 Bretton Clough

Walk #3 Mam Tor & Back Tor

Walk #4 Upper Dove & Manifold Valleys

Walk #5 Chrome Hill

Walk #6 High Wheeldon

Walk #7 Dove Valley - Wolfscote Dale

Walk #8 Lower Dovedale

Walk #9 Stanage Edge

Walk #10 Curbar Edge

Walk #11 The Roaches & Gradbach Hill

Walk #12 Lathkill Dale

Walk #13 Cave Dale & Winnats

Walk #14 NSC, Middleton Moor & Black Rock

Walk #15 Wye Valley

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Rocks and Scenery of the Peak District

Trevor D. Ford (Landmark Collector's Library)

The first geology of the Peak District book I am going to read is this excellent little book published in 2006. The name of Trevor Ford will come up again and again in this blog as he has published widely on this subject. This book is aimed at the non specialist and is full of fantastic pictures to inspire an interest in geology. I will go through each chapter with a short synopsis a pattern I will repeat for all the books. In this way we can slowly build up our knowledge in bite sized pieces.

The limestones of the white peak

Limestones form the centre of the peak. They formed in warm tropical waters when Britain was near the equator in the Carboniferous. The area was an atoll like structure surrounded by reefs, although these did not form a continuous ring in time or space. The reefs were not formed of coral but algae and indeed some are better described as mud mounds than reefs. There was a lagoonal plateau in the middle.

Toadstones or volcanic lavas and ash falls

Bubbling under this atoll basalt lava seeped out onto the floor. There is also evidence of ash fall, hexagonal jointing and sills. Wow. Toadstone is a local name for this rock type but the origin is unclear.

The Millstone Grit

Surrounding the limestone to the west, north and east are the shale and sandstone sequences of the dark peak. These were formed by deltas resulting from the erosion of large mountains in the north. About 300 million years ago the lagoon subsided and the mountains raised resulting in the cessation of limestone and the deposition of sandstone which eventually covered the limestone.

Structures, folds and faults

There is a large scale anticline covering the whole of the South Pennines with the Derbyshire massif in the middle.

Minerals and mines

There is a long history of mining in the Peak District and we will return to it again and again. Galena, fluorspar, barite and calcite were all mined in the White Peak from deposits laid down at the end of the Carboniferous. Rakes and scrins are vertical fissure deposits with flats and pipes along the bedding or in caves. There is also Blue John but we will leave that for another day.

Before the ice age: the pocket deposits

Around Brassington are pockets of sand formed by the erosion of Triassic sandstones into a limestone basin 7 million years ago. Originally a sheet the pockets formed as the limestone eroded. They form an unusual landscape as the heathland vegetation of the silica pockets contrasts with the limestone vegetation.

The great ice age

The last ice advance, the Devensian (80-10 kya), did not reach the Peak District stopping only as far south as York and South Staffordshire. The earlier Anglian (470-420 kya) did reach the Peak but the flow was too slow to carve the U-shaped vallys.

The remaining 10 chapters are all short reports about more geomorphological features such as rivers, caves, dry valleys, landslips etc all of which I am sure we will have lots more to say about in the coming months.

This book is now out of print but it features many colour photos and geological sketch maps and is well worth getting hold of.

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