THE PHYSICAL GEOLOGY

AND GEOGRAPHY OF

GREAT BRITAIN:


A MANUAL OF BRITISH GEOLOGY.




BY

A. C. RAMSAY, LL.D. F.R.S. &c.

DIRECTOR-GENERAL OF THE GEOLOGICAL SURVEYS OF THE UNITED KINGDOM.




WITH A GEOLOGICAL MAP, PRINTED IN COLOURS.

FIFTH EDITION.



LONDON:
 EDWARD STANFORD, 55 CHARING CROSS.

1878.

(All rights reserved.)



This electronic edition prepared by Dr. David C. Bossard
from original documents in the library holdings of
Dartmouth College, Hanover New Hampshire.

Bookplate

February, 2003.

Copyright © 2003 by David C. Bossard.


Geological Map of Great Britain
Geological Map of Great Britain
8x10 map - 100 ppi
8x10 map - 400 ppi



INSCRIPTION
There rolls the deep where grew the tree.
O earth, what changes hast thou seen!
There where the long street roars, hath been
The stillness of the central sea.

The hills are shadows, and they flow
From form to form, and nothing stands;
They melt like mist, the solid lands,
Like clouds they shape themselves and go.
TENNYSON.




[v. Dedication.]

DEDICATION


TO THE MEMORY

OF

SIR HENRY THOMAS DE LA BECHE,

C. B., F. R. S.

TO WHOSE EARLY TEACHINGS IN PHYSICAL GEOLOGY

I AM SO MUCH INDEBTED,

THIS BOOK IS AFFECTIONATELY DEDICATED PREFACE.


[vii Preface.]

PREFACE


____________



IN this, the fifth edition, many improvements and additions have been made. Of these, the most important consists of an account of the British Formations, showing the topographical range of each in succession, their lithological characters and the general nature of their fossils. This part of the work begins with Chapter V., and ends with Chapter XVII., and it constitutes a condensed Manual of British Stratigraphical Geology from the Laurentian to the latest Pliocene strata. The substance of these 227 pages was originally written by me for Blackie's Cyclopadia, and by the kind permission of these gentlemen, I have, with some rearrangement and many additions, made much use of the matter printed in the article.

 A leading feature in this part of the book is, that I have endeavoured to give a sketch of the Physical Geography of each successive Geological Epoch, so as to induce a scenic interest in the matter, beyond what can be gathered from mere lithological descriptions and lists of fossils, which, in the bald shape that they are

[viii Preface.]

 sometimes presented to the reader, form merely the dry bones of geology.

 By attentively reading and remembering these successive revolutions of ancient geographies, the reader will more or less realise the geological history of our country, and perceive those processes of physical evolution that, in the long lapse of time, gradually impressed on Britain its present geographical phase, which to most men seems so stable, but is, in reality, no more lasting than those which went before. As keen-eyed Chaucer well expounded five hundred years ago:-
'Well may men knowen, but it be a fool,
That every part deriveth from his hool;
Of no partie ne cantle of a thing,
But of a thing that parfit is and stable,
Descending so, till it is corumpable.
And therefore of his wisé purveyance
He hath so well beset his ordinance,
That speces of things and progressions
Shullen enduren by successions,
And not eterne, withouten any lie:
This maiest thou understand and seen at eye.'

 Among many other matters, the subject of the Miocene strata of Britain has been more largely treated of, with special reference to the absence of recognised Miocene mammalia in our country, and the subject of glacial geology has, also, been treated more fully than in previous editions, while a condensed account of all the explored English bone-caves and their contents has been added, with special reference to the question of the antiquity of man.

 I have to express my acknowledgment of the debt I

[Preface. ix]

 owe to Mr. Etheridge and Mr. Sharman; to the first for much valuable information concerning the organic relics of each formation, and also for the plan of each of the sets of figures engraved as illustrative of the formations, every one of which may be considered as more or less typical of the strata or groups of strata referred to in the text, in which, however, all of the fossils figured are not always named. Mr. Sharman executed the drawings of these fossils with his accustomed skill and accuracy.

 I have also added some landscapes. One of these, the Pass of Llanberis, fig. 86, is reduced from a coloured crayon drawing by Mr. Gillespie Prout, and fig. 87 is taken from a photograph. The original of fig. 88 was drawn by the late Sir Henry De la Beche, and fig. 89, with the dwindling ice entering the lake, is the representation of an episode in the history of the glacier, supposed and drawn by myself. The blocs perches of fig. 90 was drawn by the late Professor Edward Forbes. All of these were originally published in my paper on 'The Old Glaciers of Switzerland and North Wales.' The Gorge of the Avon is from a photograph. All the other landscapes, excepting one from my 'Geology of Arran,' have been engraved directly from drawings, as they were roughly done in sepia and pencil in my geological note books, and, together with the sections and other illustrations, many of them new, they are intended to bring before the eye the meaning of various theories propounded in this work, by help of which, anyone, by a moderate exertion of thought, may realise the

[x Preface.]

 geological origin and meaning of the physical geography and scenery of our country, and thus, as he travels to and fro, add a new pleasure to those possessed before. The colours on geological maps will then no longer seem mysterious, but become easy to comprehend when associated with the geographical contours of our island.
ANDREW C. RAMSAY.

 KENSINGTON: May 16, 1878.


INDEX

[xi. Contents]

CONTENTS.


———————



CHAPTER I.
 PAGE
Modes of Formation and General Classification of Rocks,
 Aqueous and Igneous
 1


CHAPTER II.
The different Ages of Stratified Formations-Their successive Depositions
 23


CHAPTER III.
Denudation, Synclinal and Anticlinal Curves, unconformable Stratification, and Waste produced by Chemical action.
 31


CHAPTER IV.
Igneous Rocks, Metamorphism, Shrinkage and Disturbance of the Earth's crust
38


CHAPTER V.
Laurentian, Cambrian, and Lower Silurian Rocks
55


CHAPTER VI.
Arenig, Liandeilo, and Bala Beds
 69


CHAPTER VII.
Upper Silurian Series
88


CHAPTER VIII.
Devonian and Old Red Sandstone Rocks
99


CHAPTER IX.
Carboniferous Series
119


CHAPTER X.
Permian Strata
 139


CHAPTER XI.
New Red Sandstone and Marl, and Rhætic Beds
 152


CHAPTER XII.
Liassic and Oolitic, or Jurassic Strata
 166


CHAPTER XIII.
Purbeck and Wealden Strata
 201


CHAPTER XIV.
Cretaceous Series
 212


CHAPTER XV.
Eocene Formations
 236


CHAPTER XVI.
Miocene Epoch
 259


CHAPTER XVII.
Pliocene Strata
 270


CHAPTER XVIII.
The Physical Structure of Scotland—The Highlands—The great Valleys of the Forth and Clyde—The Lammermuir, Moorfoot, and Carrick Hills
 283


CHAPTER XIX.
Recapitulation of the General Arrangement of the Stratified Formations of England
 302


CHAPTER XX.
The Mountains of Devon, Wales, and the West of England—The Valley of the Severn, and the Oolitic and Chalk Escarpments—The Hilly Carboniferous ground of the North of England, and its bordering plains and valleys—The Physical Relation of these to the Mountains of Wales and Cumberland
 315


CHAPTER XXI.
The Origin of Escarpments, and the Denudation of the Weald—Grey Wethers and the Denudation of the Eocene Strata
 336


CHAPTER XXII.
The Miocene and Pliocene Formations
 352


CHAPTER XXIII.
The Glacial Epoch-Existing Glacial Regions
 361


CHAPTER XXIV.
Old British Glaciers
 372


CHAPTER XXV.
Old British Glaciers (continued)
 398


CHAPTER XXVI.
Glacial Epoch ( continued)—Submergence and Re-elevation of
 Land, and Final Disappearance of British Glaciers
 412


CHAPTER XXVII.
Glacial Epoch ( continued)-Origin of certain lakes
 432


CHAPTER XXVIII.
Newer Pliocene Epoch ( continued)—Bone-caves and Traces of Man — Migration of Terrestrial Animals into Britain across the Drift Plains — Subsequent Separation of Britain from the Continent — Denudation of the Coasts of Britain
 456


CHAPTER XXIX.
British Climates and their Causes-Rainfall in different areas — Areas of River Drainage
 490


CHAPTER XXX.
Origin of River-valleys — Their Relation to Tablelands — Escarpments cut through by Rivers — Geological Dates of different River-valleys — The Severn, the Avon, the Thames, the Frome, and the Solent — Tributaries of the Wash and the Humber — The Eden and the Westernflowing Rivers — Scotland
 496


CHAPTER XXXI.
Relation of River-valleys and Gravels to the Glacial Drifts — River-terraces — Bones of Extinct Mammals and Human Remains found in them — Raised Beaches, &c.
 530


CHAPTER XXXII.
Qualities of River-waters — Dissolving of Limestone Rocks by Solution
 552


CHAPTER XXXIII.
Soils
 563


CHAPTER XXXIV.
Relation of the different Races of Men in Britain to the Geology of the Country
 579


CHAPTER XXXV.
Industrial Products of the Geological Formations — Origin of Lodes — Quantities of available Coal in the Coalfields — Origin of their Basin-shaped Forms — Concealed Coalfields beneath Permian, New Red, and other Strata — Summary
 590


INDEX
 621



TABLE OF FIGURES

Fig
#

Page
#

Title

Map
sect

Fossil

Scene

001

013

Stratified Rocks

002

014

Inclined Strata

003

014

Bent or Contorted Strata

004

021

Igneous veins or dykes

005

025

Succession of formations

tab

030

Table of British Formations

006

032

Denudation & Cuts

007

033

Synclinal and Anticlinal curves

008

036

Unconformable Stratification

009

039

Dykes, Lava beds & Altered strata

010

040

Granite veins, metamorphised rock

011

040

Granite and Gneiss

012

051

Heat distortion of Strata

013

059

Section across Longmynd and Shelve Country

X

014

060

Cambrian Fossils

X

015

062

Menevian Fossils (St. David's)

X

016

064

Lingula Flag Fossils

trilobite

017

066

Tremadoc Slate Fossils

Cephalopod

018

073

Llandeilo and Caradoc fossils

X

019

088

Upper Silurian Series

020

090

Upper Silurian "beaches"

021

091

Highly inclined Strata

022

093

Section of Silurian Strata near Caer Caradoc and Wenlock

X

023

094

Upper Silurian Fossils

Bellerophon, Phacops,

024

097

Upper Silurian Fossils

corals

025

101

Old Red Sandstone and Devonian Fossils

X

026

114

Old Red Sandstone Fossils

Ganoid fish,

Crustacea

tab

119

Carboniferous Rocks Ð typical section thickness

027

121

Strata in Carboniferous Series

028

130

Carboniferous Limestone Fossils

Nautilus

029

132

Coal-measure Plants and Freshwater Shells

Calamites

Lepidodendron

030

141

Section across Coal-measures, Permian and New Red strata, Nottinghamshire

X

031

148

Permian Fossils

X

tab

152

Keuper and Bunter Strata

032

154

Section across New Red Series, Shropshire

X

tab

154

Strata in section

033

156

Triassic Fossils

Fossil Tracks

034

163

Rhætic Fossils

X

035

168

Lias Fossils

Ammonites,

Extracrinus

036

170

Lias Fossils

Ichthyosaurus

037

179

Lower Oolitic Fossils

Ammonites, Nautilus

038

186

Middle Oolitic Fossils

039

187

Section of Oolitic and Purbeck strata, Isle of Portland

X

040

189

Upper Oolite Fossils

Pecten

tab

202

Purbeck and Wealden Series

041

204

Purbeck and Wealden Fossils

X

tab

212

Cretaceous Series

042

215

Fossils of Atherfield Clay and Lower Greensand

X

043

219

Gault Fossils

X

044

225

Upper Greensand Fossils

X

045

229

Fossils of the Chalk

X

tab

238

Subdivisions of Eocene Strata

046

240

Fossils from the Thanet Sand

X

047

241

Section across Isle of Wight

X

tab

241

Strata in Section

048

243

Fossils from Woolwich and Reading Beds

X

049

246

Fossils from London Clay

Cassidaria

050

250

Fossils of Bracklesham and Barton Beds

Murex

051

253

Fossils of Headon and Bembridge Beds

Palæotherium

tab

270

Subdivisions of the Suffolk and Norfolk (Norwich) Crag

052

271

Coralline Crag Fossils

X

053

273

Red Crag Fossils

Trophon, Capulus

054

285

Strata in Sutherland and Caithness, Northern Scotland (Map, line 4)

X

055

287

Section Grampian Mountains to Lammermuir Hills

X

056

289

View of Suilven, Canisp, and the neighbourhood, Sutherland.

X

057

304

Section from the Menai Straits across Wales (Map, Line 6)

X

tab

304

Description of strata in Section

058

310

Strata of Portland Beds

059

313

Overlap of the Oolitic and the other Strata by Cretaceous Formations

060

319

Potholes in the Chalk of Savernake Forest, near Marlborough.

X

061

320

Erosion of Eocene Strata.

062

322

Section across the Cambrian and psrt of the Lower Silurian rocks of Merionethshire

X

063

325

Section across the Carboniferous Rocks of Derbyshire and lancashire.

X

064

327

Topography around Kinder Scout

065

328

Pillars of stone at Kinder Scout

066

329

tumbled ruins along valleys of erosion

067

330

Section from Snowdon to the East of England.

X

068

332

Section from Cumberland towards Bridlington Bay.

X

069

334

Section east of the Vale of eden to the German ocean

X

070

336

Strata dip at Escarpments

071

337

Wealden area escarpments

072

339

Effect of a partial submergence of the Weald (Map, line 10)

X

073

343

Diagrammatic Section across the Weald

074

346

Section across the Isle of Wight

X

075

347

Section across the Isle of Purbeck.

X

076

349

Chalk and Eocene strata denudation.

077

356

Miocene Lavas, Scuir of Eigg

078

367

Imaginary Section of a Swiss Glacier

X

079

373

Mountains of Ross-shire

X

080

381

Fidra Island, North Berwick, Firth of Forth

X

081

383

Bass Rock, Firth of Forth

X

tab

388

Boulder-Clay. Proportions of Stones and Boulders, Tynemouth

tab

389

Boulder-Clay. Stones from Magnesian Limestone, Till South of Tynemouth.

082

390

Boulder-Clay strata from Glacial epoch.

083

391

Boulder-clay strata.

084

413

Section of Cambrian Rock at Slate quarry SE of Caernarvon.

085

417

Post-Pliocene Fossils, Clyde beds

X

086

418

Pass of Llanberis

X

087

420

Moraines and Roches Moutonnées between Cwm-glas and Blaen-y-nant, Pass of Llanberis.

X

088

423

Glacier of the Pass of Llanberis

X

089

425

An episode in the history of the Glacier of Llanberis.

X

090

426

Roche Moutonnée with Blocs Perchès, Pont-y-gromlech, Pass of Llanberis.

X

091

428

Old glacier cirques in Arran, from Lagan Hills.

X

092

442

Lake of Geneva and Soundings

093

442

Old Glacier of the Rhone, covering what is now the Lake of Geneva.

094

450

Loch Erriboll, Sutherland.

X

095

452

Mouth of Loch Etive, Connel Ferry.

X

tab

466

animal bones in Boulder-Clay caverns

tab

475

quantity of animal bones in Caves in Somerset

096

479

Brixham Cave cross-section

X

097

497

General section across the Lower silurian strata of Cardiganshire

098

500

denudation and faults

099

501

formation of escarpment of the Beacons of Brecon and the Caermarthen Fans, South Wales.

100

505

General Arrangement of the Lower Secondary Formation before the Deposition of the Upper Secondary strata.

101

507

Early Overlap of the Cretaceous strata on the Lower Secondary Formation.

102

509

Post-Miocene Westerly dip of the Cretaceous strata of England.

103

512

Gorge of the Avon at Clifton, Bristol, looking down the rive.

X

104

521

Section from the cambrian Mountains across the Vale of Eden to the Northumberland Coalfield.

X

105

531

Boulder-clay filling a valley

106

532

Cross-section through the Thames

107

534

Diagram of river bends

108

534

typical section a across river bend

109

534

typical section b across river bend

110

535

Formation of a Cliff by a stream.

111

537

terraces cut out by rivers

112

540

Palæolithic flint hatchet, Herne Bay

flint hatchet

113

545

Neolithic hatchet, bed of the Thames, Erith

hatchet

114

561

Dissolving of rocks: accumulations of flint

115

601

Diagram showing the Origin of the Basin-shaped form of many Coalfields.