The Alps, A Natural Companion

THE ALPS

A Natural Companion

Jim Langley & Paul Gannon

With a Foreword by John Beatty

Geology | Flowers | Walks



THE ALPS

A Natural Companion

Geology | Flowers | Walks

Jim Langley & Paul Gannon

Oxford Alpine Club

The Alps, A Natural Companion

The Alps

A Natural Companion

Geology | Flowers | Walks

By Jim Langley and Paul Gannon
1st Edition, October 2019

Published by the Oxford Alpine Club
© 2019 Oxford Alpine Club
www.oxfordalpineclub.co.uk
ISBN 978–1–913167–01–1
A catalogue record for this book is available from the British Library.
Jim Langley and Paul Gannon have asserted their right under the Copyright Designs and Patents Act 1988
to be identi ed as the authors of this work.
All uncredited photographs by Jim Langley and Paul Gannon.
Graphics and design by Lina Arthur.

Cartography by GeoGraphics
Some maps based on source data from www.openstreetmap.org.
All rights reserved

Other than in the case of brief quotations in reviews, no part of this publication may be reproduced or distributed in any form without
prior written permission from the publisher. The authors and publisher accept no responsibility for any injury or loss caused as a result of
using this book. Images and text contained within this book do not necessarily represent the views or opinions of the Oxford Alpine Club.
Front cover image: The Matterhorn, Switzerland.

The Authors

Paul Gannon Jim Langley

Paul Gannon is a science and technology writer. Jim Langley is a specialist in alpine �lowers. He has
He is the author of nine books, including the a Master’s degree in conservation and land man-
popular Rock Trails series about the geology agement, and holds the International Mountain
and scenery of British hillwalking areas (Snow- Leader and Winter Mountain Leader quali�ica-
donia, Lakeland, the Scottish Highlands, the Peak tions. He also runs Nature’s Work (www.natures-
District, and South Wales). He also runs geology work.co.uk), an educational consultancy that
workshops in Snowdonia and the Lake District.
www.paulgannonbooks.co.uk provides a range of guided walks, training events,

and bespoke outdoor learning programmes.

Acknowledgments

There are many people without whose support, assistance and guidance this book would not have been
possible. Firstly, Pete Kay, who sparked my interest in alpine �lowers many years ago and, along with
Hywel Roberts, shared a passion for exploring Snowdonian relict arctic-alpine �lower communities. I

would also like to thank those whose technical knowledge and skills have proved invaluable, namely
George Manley for his wonderful illustrations of �lowers and their structures, Professor John Good for
checking �lower identi�ications and botanical names, John Rowell and Marion Waine for their assistance

with photo-editing, and Rob Collister for his kindness in reading the ecology section and making useful
suggestions but also for sharing in botanical forays. Finally, I would like to thank Edith Kreutner for joining

me on walks in Austria and for supplying photos, along with Allan Hartley, of Austrian landscapes. JL
I would like to thank Ali Rowsell, author of Switzerland’s Jura Crest Trail, for photos of the Jura and Julia
Tregaskis-Allen of Tracks and Trails (www.tracks-and-trails.com) for photos of the Subalpine Chain. I

am also grateful to Tim Matschak for his guidance on German terms, Reg Atherton for his advice on the
Tour of Mont Blanc, and Dr Alison Parker for checking the geology section. Last but not least, I would

like to thank Jim Langley for conceiving the idea of this book, and Lina Arthur and Steve Broadbent of

the Oxford Alpine Club for enthusiastically taking up and expressing our idea. PG

3

The Alps, A Natural Companion

Kitzbühel

Basel Zurich Innsbruck AUSTRIA Hohe Tauern
Swiss Mittelland
DijonFRANCE Habicht Grossglockner
Macon Lucerne
Jura
Bern SWITZERLAND
Lausanne Eiger GAaotrtMhaarsdsiMf assif Dolomites
Piz Quattervals
Piz Bernina Bolzano Marmolada

Geneva Sion

ChaSumbCalbCphhineaaeirnmy onixBMGlaornannct Matterhorn Massif Trento

Lyon Aosta Rosa Como
Milan
ParadisMoonte Verona Venice

Grenoble Dora Maira
Écrins
Turin ITALY

Genoa Adriatic
Sea

Argentera

Overview of the Alps, showing national borders and main towns.

Jura Helvetic Alps Engadine Hohe Tauern
Pre-Alps Penninic Alps Eastern Alps

Dent Blanche Southern Alps

Alps

Helvetic
Penninic Alps

Simpli ed tectonic map, showing the approximate locations of the main geological units.

4

Contents

Contents

Foreword .................................................................................................................................... 6
Introduction............................................................................................................................... 8

SECTION I | GEOLOGY
1. The Geography of the Alps .......................................................................................... 11
2. The Ancient Origins of the Alps .................................................................................. 15
3. Sedimentary Rocks of the Alps................................................................................... 21
4. Thrusting the Alps Upwards........................................................................................ 29
5. Some Complexities........................................................................................................ 43
6. Mountains Come and Mountains Go ........................................................................ 49
7. Alpine Glaciation............................................................................................................ 59

SECTION II | AREA NOTES
8. The French Alps .............................................................................................................. 79
9. The Swiss Alps................................................................................................................. 95
10. The Eastern Alps..........................................................................................................113
11. The Southern Alps ......................................................................................................119

SECTION III | FLOWERS
12. Life in the Alpine Zone ..............................................................................................125
13. The Alpine Environment ...........................................................................................135
14. The Uses of Alpine Plants..........................................................................................145
15. Flower Identi cation Guide......................................................................................151

SECTION IV | WALKS
16. Walks .............................................................................................................................235

Glossary of Botanical Terms..................................................................................................284
Glossary of Geological Terms ...............................................................................................286
Bibliography of Ecology Sources.........................................................................................289
Bibliography of Geology Sources........................................................................................290
Index ..........................................................................................................................................292
Index of Flowers ......................................................................................................................296

5

The Alps, A Natural Companion

Foreword

High above the Bondasca Valley of Bregaglia, night mist whispered through the trees. In the
thin beams of our head torches a narrow pathway led steeply upward through boulders,
shadows, dry cones and needles, cushion mosses and draping lichens, up and up to the
forest’s edge. In the aromatic savour of mountain pine, memories �lowed with us through
the darkness. With shortening breaths and heavy packs, we were reminded on this relent-
less trail that mountains are big, and mountains are alive.
Dawn, and searing rays pierced the forest canopy to herald our emergence into the vast
amphitheatre below the Piz Badile. Huge rock ridges, walls and spires of granite �illed the
sky. Shielding our eyes, we gazed aloft, scanning the intricate climb ahead. The dark trees
had released us into the luminous intensity of mountain space and light.
As we rested for a while in the warming sun, birdsong echoed from the now distant wood-
lands. Amongst the open hillocks and rock slabs around us, dense carpets of alpine �lowers
were drying from the night-time dew. Their petals, moving now in the mountain breeze,
lent a sense of transitory glory beneath the might and drama of the great peaks. We began
to look closely. Goldenrod, snowbells, orchids, lilies, and avens, forms of in�inite variety were
clinging to life in the rich, glacial clays of these high mountains. A peregrine falcon, drifting in
vapours a thousand feet higher, spied for rock partridge in nearby screes. From this high alp
we looked out across peaks and valleys at Europe still in shadow, into the teeming throngs
of humanity, the commerce, art, science and structures of our age, gladdened to be here for
a short while, resting amongst quiet natural forces.

6

Foreword

Stemless gentians ourish in the alpine sun below Col de Torrent, with the summits of Grand Cornier and Dent Blanche in the distance.

For me, a mountain experience has always been about looking and wondering. ‘Connecting
with nature’ is a much-used phrase these days, but how? The nature writer Henry David
Thoreau would have advised us to resign ourselves to the in�luences of the earth. To connect.
Often to understand a single fragment of the whole is most invigorating and leads us, over
a lifetime, to understand relationships between all living things and forces. After all, it is
the relationships of things that ultimately hold the human imagination. And it is here in
our living mountain landscapes that we are most exposed to fragile life forms, and tectonic
and climatic forces. In these explorations and moments of wonder, we may �ind our sense
of place in the world.

Looking makes me curious. Wondering helps me imagine. In this lovely book, Jim Langley
and Paul Gannon piece together the fragments that help us to understand the sheer diversity
and wealth of our alpine world.

In the month of June, I accompanied Jim into the heart of a high cwm in the mountains of
North Wales, in search of one of Britain’s rarest relict alpine �lower species, the Snowdon

lily, Gagea serotina. On this day of blasting rain and gushing streams, we scrambled through

crags and boulders in the hope of witnessing this elusive and fragile tiny form of life. After
some hours I lay in the soggy moss, bridged precariously across a small fern-�illed chasm,
and looked closely at this tiniest wonder, less than two centimetres in height. I didn’t see
a half-closed, bedraggled plant; I saw only what it meant to me… a delicate and simple
�lower living in an ancient, glaciated world of gothic peaks. A spectacular representative
of this living mountain. I closed my eyes and saw the golden peaks of Bregaglia, and knew

that the Alps awaited.

John Beatty Bamford, October 2019

7

The Alps, A Natural Companion

The steely blue owers of queen of the Alps, Col du Lauteret, Écrins National Park, French Alps.

Introduction

The Alps are one of the world’s great continents. The underlying rocks were
mountain ranges, containing a variety and crumpled, folded and transformed into
density of geology, scenery and plant life massive mountains. The result is a complex
that enthralls millions of people every year. mixture of many different rock types and a
Iconic peaks such as Mont Blanc, the Mat- variety of geological features. Glacial erosion
terhorn and the Eiger are among Europe’s then carved the mountains into the present
greatest natural wonders. Though a few landscape.
roads and railways cross the Alps, skiing
infrastructure litters some lower slopes, Despite the challenging climatic conditions,
and scores of alpine huts are rooted high in the Alps are also home to a stunning array of
the mountains, the Alps remain an authentic wild �lowers, which turn a summer visit into
natural landscape at the heart of a densely a glorious romp through a vibrant world of
populated continent. colour.

The Alps have an amazing geological story This book is aimed at the visitor to the Alps
to tell. Over the last 100 million years, con- who would like to learn a bit more about the
tinents and oceans became mixed up in natural history of this exceptionally beauti-
the collision of the European and African ful and easily accessible mountain realm.

8

Introduction

Ibex grazing outside the Britannia Hut in the Swiss Alps; Hohlaub Glacier in the background.

The �irst section outlines and clari�ies the The second section outlines the varied adap-
complex geological story, before looking tations that allow Alpine plants to survive in
in more detail at the geology of the most this extreme environment. It also provides
popular areas of the Alps and some speci�ic a plant identi�ication guide covering over
natural wonders. 300 of the plants found in the Alpine range.
The guide is organised by the colour of the
The Alps are often said to be a particularly �lowers and is arranged to make it as easy as
complex mountain range, but this may only possible to identify them. As in the geology
seem to be the case because the Alps have section, technical language is avoided where
been more intensely studied than any other possible. Glossaries of technical geological
range. This book aims to provide a compre- and botanical terms are provided on page 284
hensible insight into these mountains, which and page 286 for handy reference.
is accessible to the general reader.
The third section outlines 20 walks, ranging
No special geological knowledge is needed from fairly easy half-day strolls to more
and technical language is kept to a minimum. demanding multi-day trips, among some of
There is some jargon, such as ‘plate tecton- the very best Alpine scenery, where you can
ics’ and the like, but everything is explained see the geology and, at the right time of year,
in straightforward language. the spectacular �lowers of the Alps.

9

The Alps, A Natural Companion | Geology

Dorfer Tal in the Granatspitzengruppe (granite summit group). The
pyramid-shaped mountain in the background is Medelzkopf (2761m).
Photo: Edith Kreutner

SGECETIOONLI OGY

10

1. Geography of the Alps

Photo 1.0 | The Matterhorn viewed from the summit of Pigne d’Arolla in the early morning light.

1. The Geography of the Alps

Overview up of a supercontinent, Pangaea, which
existed some 250 million years ago (around
De�ining where the Alps begin and end is the time of the dinosaurs).
rather arbitrary. The Alps are part of a
chain of mountain ranges running from the In this book we have focused on the geology
Pyrenees, the Betic Cordillera in Spain and and �lowers of the traditional Alpine range,
the North African Atlas mountains in the which stretches about 1,200 kilometres
west, via the Alps themselves, to the Car- from France in the west, via Switzerland
pathians and Dinarides, and beyond into the (and Liechtenstein), Italy and Germany,
Zagros mountains and the Himalaya. to Austria in the east, just reaching into
Slovenia in the south-east (see page 4 for
All these mountain ranges are relatively overview maps). From north to south the
young geologically and were (and indeed distance is much less – the Alps are between
still are being) created following the break 150 and 200 kilometres wide.

11

The Alps, A Natural Companion | Geology

Photo 1.1 | Panorama of the French–Italian border on the Mont Blanc massif. Left–right: Aiguille Savoie, Pointe Isabelle, Aiguille Rouge de
Triolet, Aiguille de Triolet and Mont Dolent.

The Alpine range forms an elongated arc. This Depending on the area measured, the Alps
is most evident in the Western Alps, where cover about 200,000 square kilometres of
the range runs roughly north–south, while Central Europe, of which 110,000 square
near the French–Swiss border it is more kilometres are higher than 2,000 metres.
clearly on an east–west axis, with a north- Austria accounts for some 35% of the
west–south-east axis running into Slovenia. Alpine mountain area, Italy for 23%, France
for 20%, Switzerland and Liechtenstein
When thinking about the Alps, we should combined for 13%, Germany for 5% and
also remember the areas to the north and Slovenia for 2%.
south of the Alps proper. North of the Swiss
Alps lies the Swiss Mittelland (middle land), The summit of Mont Blanc, near where the
while north of the Austrian and German Alps French, Swiss and Italian borders meet,
is the Swabian–Bavarian High Plain (Schwä- is the highest point in the range at 4,810
bische–bayerischen Hochebene). To the south, metres. It is one of 128 Alpine peaks that
in Italy, lies the Po Basin. These are all com- are higher than 4,000 metres. Most of these
paratively low-lying areas or basins, where mega-peaks are found in the Mont Blanc
vast quantities of material eroded from the massif and in the Aar massif in Central
Alpine mountains have been deposited. Switzerland, though others are found in
the Écrins, Gran Paradiso, Monte Rosa and
Further north, the relatively low Jura moun- Piz Bernina areas. They are formed from a
tains are really the outermost part of the group of very tough rocks, which are known
Alpine range and were created by the same as ancient crystalline basement rocks.
compressive forces. However, the Jura formed
comparatively recently – 5 million years ago.

12

1. Geography of the Alps

In general, the further east one travels, the in slow-moving, linear waves, with one wave
lower the mountains are in height, though of rocks being piled up on top of another
there are exceptions to this in the Ortler Alps (see Chapter 4). This geological feature has
and the Hohe Tauern in the Eastern Alps. determined the patterns of travel and settle-
ment in the core of the Alps, as well as the
Alpine Rivers drainage routes.

One notable feature of the geography of Eventually, both rivers curve north – the
the Central Alps in Switzerland is that the Rhône at Martigny and the Rhine at Chur.
two main rivers, the Rhine and the Rhône, The rivers cut through the main Alpine
start very close to each other, but end up range by exploiting geological features. The
emptying their waters into the North Sea Rhine picks its way north roughly along the
and the Mediterranean respectively. boundary between the different geologies of
the Swiss Alps and the Eastern Alps, while
The Rhône rises west of the Furka Pass, ini- the Rhône exploits a weakened area of rock
tially �lowing west, while the Rhine rises east created during the mountain-building phase
of the Oberalp Pass and initially �lows east. to bear northwards.
Both rivers run along the same boundary
between geological zones of the Alps on an Similarly, the Inn, Mur (Mürz) and Drau
east–west axis. This boundary was created in the Eastern Alps have noticeable linear
by a huge chunk of the African continent sections that run parallel to the long axis of
pushing northwards into Europe, piling up the Alpine range. In contrast, the Po, which
the rocks before it like a bulldozer. We can drains the Southern Alps, �lows towards the
loosely imagine the rocks being pushed up Adriatic without the linear diversion of the
other rivers.

Rhine Danube

Swabian-Bavarian High Plain ALPS
EASTERN
hSôwAniaSssreWMMFIiautSstrkeSsailflPAaansLsdPSPizChBeurrninaRhine Inn Mu r
Hohe Tauern Drau

Jura

Martigny R Ortler AlpMs armolada
Mont Blanc
Matterhorn SOUTHERN ALPS

Rhône Gran Paradiso Po

FRENCH ALPS Adriatic
Sea
Écrins

Map 1.1 | The Alps and the Po Basin.

13

The Alps, A Natural Companion | Geology

Human Geography Trekking, climbing, skiing and many other
physical activities take place in the moun-
The term ‘Alps’ derives from the label tains, as does a great deal of less active
used for the alpine pastures that were tourism, aided by a plethora of mechanical
tilled by generations of hardy mountain- means of gaining height and the enviable
dwellers who lived wherever they could railway systems, particularly in Switzerland.
�ind adequate space for crops and grazing.
When men of science �irst started enquir- Today, the Alps face many challenges due
ing of the locals about the names of peaks to environmental changes. Due to climate
and pointing upwards, the farmers usually change, the glacial ice cover in the Alps is
offered the name of their pastures rather melting, with potentially signi�icant conse-
than the peaks, and so the name ‘Alps’ grew quences for those who live and work there,
to cover the whole mountain range. as well as for the thousands of visitors who
�lock to see the mountains’ rocky majesty.
The Alps constitute a tremendous physical
barrier between Northern and Southern For overview maps of the Alps, see page 4.
Europe, though the mountain range has also For more detailed maps of the French, Swiss,
played a unifying role in European history. Eastern and Southern Alps, see pages 79, 95,
The Alps are a symbol of Europe, as well as its 113 and 119.
best known and most loved mountain range.

Despite being one of the world’s smaller

mountain areas, the Alps are the most

densely populated mountain range on
Earth. Today, the Alps are home to 14 million
people (about the same as London and the
south-east of England combined). The bulk
of the Alpine population lives in the main

valleys that cut deep into the mountains.

A score of different dialects, including Photo 1.2 | The early eastward- owing waters of the Rhine,
Occitan, Romansch and Ladin, are spoken passing through the Rhine Gorge.
in the Alps, though the most common lan-
guages are German, French and Italian.

The Alps are one of Europe’s most popular
playgrounds. Some estimates suggest that as
many as 120 million separate visits are made
by tourists to the Alps every year, totalling
some 220 million overnight stays. However,
these visits are very unevenly distributed, as
visitors congregate in the most popular areas,
such as Chamonix, Grindelwald and Zermatt.

14

2. The Ancient Origins of the Alps

Photo 2.0 | The ancient crystalline massif of the Aiguilles Rouges.

2. The Ancient Origins of the Alps

The creation of the Alpine mountains was not were laid down in warm, shallow seas (see
a single event. Rather, it was a long, drawn- page 24). These rocks now form some of the
out series of processes lasting many tens of most dramatically shaped mountains in the
millions of years. The choice of when to start Alpine mountain range, such as the Helvetic
this account of the process of creating the Alps in the Central and Western Alps, and the
Alpine rocks and then pushing them up into a Dolomites in the Southern Alps.
mountain range is thus fairly arbitrary. In fact,
it’s a bit like stepping onto a conveyor belt at However, these rocks were laid down on
some random midpoint on its journey. Most top of a basement of preexisting rocks,
geological accounts of the Alps begin about known as ancient crystalline rocks, which
300 million years ago, when great swathes were later thrust upwards and now consti-
of sedimentary rocks, particularly limestone, tute many of the highest points in the Alps,

15

The Alps, A Natural Companion | Geology

including the Mont Blanc and Aar massifs. In Many interesting things happen at these col-
the context of the Alps, ‘ancient’ can mean lision points, especially mountain building.
anything more than 300 million years old Today, this is most obvious in the Himalaya,
and some of these rocks are around 800 where the Indian continent is crashing into
million years old (though even this is fairly the Asian continent at a rate of about 5 to 10
young in geological terms, given that the centimetres per year.
Earth is about 4.5 billion years old).
To put it simply, the Alps resulted from part
It would clearly be remiss of any author of the proto-African continent crashing into
writing about the geology of the Alps not the proto-European continent. This process
to cover the origins of the rocks of the Mont started about 100 million years ago but its
Blanc massif, so to avoid leaping backwards most intense phase was 40 to 25 million
to incorporate the earlier rocks, this account years ago.
starts somewhat earlier in the Earth’s
history, around 600 million years ago. This collision is still going on today, but
much less intensely. The southern margins
Starting so long ago also allows us to intro- of the Alps are being pushed north-west
duce some basic concepts of geological at a rate of about 1.2 millimetres per year,
theory, especially regarding plate tecton- while their northern limits are moving in the
ics, that are directly relevant to the creation same direction at just 0.7 millimetres per
of the Alps. year. This means that the Alps are still con-
tracting by about 0.5 millimetres per year
Plate Tectonics as the collision pushes the Alps upwards.
However, destruction of the mountains
The theory of plate tectonics was one of the (through weathering and erosion) is hap-
great scienti�ic revolutions of the twentieth pening more rapidly than they are currently
century and is fundamental to our under- being pushed upwards.
standing of how mountain ranges like the
Alps are built. The Structure of the Earth

The basic concept is that the Earth’s surface To understand why tectonic plates move
is divided into a number of independent but around the Earth, and how this causes
interlocking tectonic plates, which move mountain building, we need to look brie�ly
(quite slowly, at a rate of a couple of cen- at the structure of the Earth.
timetres per year) around the globe. The
plates can slide past one another (as they The Earth’s core is extremely hot. This heat
do along the great San Andreas fault zone moves slowly up through the next layer of
on the west coast of North America), pull the Earth, the mantle. The mantle makes up
away from one another (as is happening in about 60% of the Earth’s volume and extends
the African Rift Valley and also, out of sight, from the core to close to the Earth’s surface.
in the middle of the Atlantic Ocean), or they
can collide, crashing into each other. The mantle is solid not molten, but since it is
close to its melting temperature, it is ductile

16

2. The Ancient Origins of the Alps

Tectonic Crust the layer of the Earth that we know and exist
plates Lithospheric upon, and will be the focus of our discussion
of the Alpine mountain-building processes.
mantle
To be strictly accurate, we should note that
Mantle the tectonic plates are made up of both the
crust and the outermost layer of the mantle
Liquid outer core (the lithospheric mantle). We can largely
Solid inner core ignore this, because we will mainly be
focusing on processes in the crust. However,
the lithospheric mantle will occasionally be
mentioned.

Diagram 2.1 | The composition and internal structure of the Earth. There are two types of crust – oceanic and
continental. Oceanic crust is found under
(i.e. it can be deformed without being frac- oceans; continental crust constitutes the
tured). This means that heat can �low through continents and the shallow seabed beside
the mantle in great convection currents, them. The key difference is that oceanic
moving heat towards the surface. It is thought crust is thinner and more dense than con-
that it is these convection currents that move tinental crust. Oceanic crust is only about
the tectonic plates (see Diagram 2.2). 8 kilometres thick, whereas continental
crust can be anything between 20 and 80
The outermost layer of the Earth is known kilometres thick. As we shall see, the differ-
as the crust. It is cool and brittle. The crust is ence in the density of the two types of crust
is signi�icant in the processes that created
the Alpine mountain range.

Eruption of lava below sea level Oceanic crust and upper mantle
creates new oceanic crust which (tectonic plate) subducts when it
spreads out in both directions
meets continental crust

Continental plate Oceanic plate Oceanic plate Continental plate

Convection currents in the Subducted plate is‘recycled’
ductile rock of the mantle and carried down by
convection currents
move rock and heat
towards the surface

Diagram 2.2 | Oceanic and continental plates.

17

The Alps, A Natural Companion | Geology

The Creation of Metamorphic crystals that make up the rock are changed
Crystalline Rocks into different minerals. Metamorphosis (see
page 46) is one of two processes that result in
About 600 million years ago a long, drawn-out the formation of crystalline rocks, the other
process was under way that led, by about 300 being igneous activity.
million years ago, to the creation of a single
massive continent called Pangaea. As the con- Even as the mountains are being built,
tinental plates bunched together to form the weathering and erosion of the mountain
supercontinent, they were involved in several range above sea level reduce the weight
collisions, which produced mountain ranges on the deep zone. As the mountains are
(though this was many millions of years reduced in height, their deep roots (and the
before the Alps were created). metamorphic rocks formed there) move
upwards towards the surface and form the
The mountain-building episodes that lower part of the crust.
occurred during the creation of Pangaea
produced the ancient crystalline metamor- Mountain-building Episodes
phic rocks that formed the basement on
which later Alpine rocks were laid down. There were three major episodes of
mountain building which created the meta-
When two continents collide, the rocks in morphic crystalline rocks. The Cadomian
the area are crumpled and pushed upwards mountain-building episode occurred around
to form mountains. However, the mountain- 600 million years ago. The Caledonian was
building zone doesn’t just extend upwards. a period of mountain building from 450
In fact, it also stretches downwards, thick- million years ago until 400 million years ago.
ening the crust substantially and creating a The Variscan mountain-building phase (pre-
massive deep zone, many times deeper than viously known as the Hercynian) extended
the mountains are high. from 350 to 300 million years ago.

Within this deep zone the pressures and The areas created during the Variscan
temperatures reach high levels and existing phase include the rocks of the Vosges, the
rocks may as a result undergo some form Black Forest and the Massif Central on the
of transformation or metamorphosis, such northern and north-western margins of
as recrystallisation, in which the mineral

Continental plates move towards each other Continental plates collide and mountain building occurs
as oceanic plate is subducted away Mountain ranges

Continental Continental Continental Continental
plate plate plate plate

Subducting Suture
oceanic plate
Diagram 2.3 | Plate collisions and mountain building.

18

2. The Ancient Origins of the Alps

the present-day Alps, as well as a lot of the

ancient crystalline rocks of the Alps proper.

As a result, today Variscan metamorphic
rocks occupy vast areas of the Eastern,
Central and Western Alps (though not the
Southern Alps). The rock types include
gneiss, schist, quartzite and many other
types of metamorphic rock.

The Creation of Igneous Crystalline
Rocks

The Variscan mountain-building episode Photo 2.1 | Metamorphic crystalline rock – Aiguilles Rouges gneiss.
also led to the melting of sections of the con-
tinental crust at the base of the thickened
crust. This was a form of igneous activity
as it involved the melting of the rocks. The
molten rock rose some of the way towards
the surface, slowly losing heat and solidify-
ing into the crystalline rock we call granite.

This granite, created 305 to 315 million Photo 2.2 | Metamorphic crystalline rock – schist.
years ago, can be found in several places
in the Alps, in particular the greater part
of the Mont Blanc massif and much of the
Aar massif. The granite intruded itself into
the earlier metamorphic rock so the Alpine
basement consists of both metamorphic
rocks and granite, an igneous rock.

The later Alpine mountain-building episode
that occurred between 40 and 45 million
years ago pushed some of these ancient
crystalline basement rocks up to the surface,
where they became the upper crust. Today,
ancient crystalline rocks comprise about
50% of the surface of the Alps.

Photo 2.3 | Igneous crystalline rock – granite.

19

The Alps, A Natural Companion | Geology

Rock Types

Igneous rocks Sedimentary Rocks
Igneous rocks are created from molten rock Sedimentary rocks (see Chapter 3) are
or magma which forms beneath the Earth’s mainly created by the weathering and
surface. The magma is either erupted by erosion of preexisting igneous or meta-
volcanoes onto the surface (as lava or as morphic rocks. These eroded sediments
great clouds of hot, pyroclastic fragments) are carried down and deposited in seas
or intruded upwards into existing rock and oceans where they are transformed
below the surface. into sedimentary rocks, most commonly
As it cools, the magma usually solidi es sandstone and mudstone.
into crystalline form. Faster cooling on the There are two other major types of sedi-
Earth’s surface creates ner crystals and mentary rock. Limestone forms from
produces rocks such as rhyolite; slower calcium carbonate-rich material on the
cooling below the Earth’s surface creates seabed in warm, shallow seas. This is most
larger crystals and results in rocks such as commonly the bones and shells of marine
granite. organisms which are deposited and com-
Metamorphic Rocks pacted on the seabed.
Metamorphic rocks are created by the Evaporites are sedimentary rocks that
transformation (or metamorphosis) of are created when seawater evaporates in
previously existing rocks. These may be coastal lagoon environments, leaving salts
igneous, sedimentary or come from a that form rocks such as gypsum. Evapor-
previous metamorphic event; some may ites are quite weak rocks and were often
even have experienced several episodes involved in the thrusting (see Chapter 4)
of metamorphosis. that occurred during the Alpine mountain-
Metamorphosis results when those pre- building episode.
existing rocks are subjected to great heat
and pressure in a mountain-building zone.
This often recrystallises existing minerals
into di erent ones, creating di erent types
of crystalline rock. For example, limestone
can be metamorphosed into marble; sand-
stone can be changed into quartzite.
Many di erent types of metamorphic rock
can be created, depending on the original
rock type, the temperatures and pressures
to which it is subject, and the duration of
the process (see page 46).

20

3. Sedimentary Rocks of the Alps

Photo 3.0 | Sedimentary rocks of the Faulhorn massif, Swiss Alps.

3. Sedimentary Rocks of the Alps

In the previous chapter we saw that the of the crust. Around 300 million years ago,
continents had collected into a single super- these rocks formed the upper part of the
continent, Pangaea, and that the continen- crust in the continental zone of the future
tal collisions which occurred during its long, European continent.
drawn-out assembly involved several moun-
tain-building episodes. The Break-up of Pangaea

During these upheavals, previously existing By 250 million years ago, Pangaea was
rocks were transformed (metamorphosed) just about fully formed as a single, global
by heat and pressure deep in mountain- supercontinent, but after just a few tens of
building zones. Other crystalline rocks, in millions of years of unity the slowly assem-
particular granite, were formed by melting bled supercontinent began equally slowly to
and subsequent cooling of the lowest part break up. By about 200 million years ago the

21

The Alps, A Natural Companion | Geology

The Creation of Continental Rocks

Laurasia When two tectonic plates start to pull away
from each other, the plates are stretched
Tethys and thinned, falling below sea level. Even-
Ocean tually they are pulled apart, allowing the
mantle rocks below to come up almost to
Gondwana the sub-sea surface. As the stretching con-
tinues, the pressure near the surface falls,
Diagram 3.1 | The supercontinent Pangaea begins to break up into which lowers the melting point of the
two parts – Laurasia and Gondwana. The Tethys Ocean spreads into mantle rocks. This causes the uppermost
the gap between them. mantle rocks to melt and become magma,
which erupts as outpourings of lava along
southern part of Pangaea, Gondwana (con- the line at which the two plates are pulling
taining proto-Africa, proto-South America, apart (see Diagram 3.2).
proto-Australasia and proto-Antarctica), had
started to shear off from the northern part, Since these eruptions occur below sea level,
Laurasia (containing proto-North America, the water rapidly quenches the hot lava and
proto-Europe and proto-Asia), creating a it cools to create a rock type called basalt,
narrow gap between the two dividing halves often in a form known as pillow lava. Over
of Pangaea. As the gap widened, an ocean time, the once-new basalt moves further and
(called the Tethys Ocean by geologists) further away from where it formed as the
spread into it, gradually increasing in size ocean continues to widen. The eruptions are
as the gap continued to grow. thus creating new oceanic plate under the
widening ocean.
This expanding ocean and the seas on its
continental margins were the environ- When the widening oceanic plate collides
ment in which the sedimentary rocks were with a continental plate, the thin, dense
created from continental rocks over many oceanic crust is forced down below the
millions of years. To understand how sedi- thicker, less dense (and thus more buoyant)
mentary rocks are created, we must �irst continental crust. This is known as subduc-
look at what they are created from – conti- tion (see Diagram 3.3). In effect, the basaltic
nental rocks. crust is recycled by being pulled back down
into the mantle. This means that oceanic

European upper crust Tethys Ocean African upper crust Tectonic plate
European lower crust Magma African lower crust
Lithospheric mantle Lithospheric mantle
Mantle

New oceanic plate
Diagram 3.2 | New oceanic plate is created as the plates pull apart.

22

3. Sedimentary Rocks of the Alps

Volcanic eruptions Cooling lava and
pyroclastic fragments
Material is scraped o solidify into new rocks
the descending oceanic Molten magma rises
plate and accumulates towards the surface

Oceanic plate Oceanic crust Ocean Continental crust Continental plate
Lithospheric mantle

Subduction Lithospheric mantle

Mantle Water is released and rocks Mantle
melt, creating magma

Diagram 3.3 | Subduction of oceanic plate and accumulation of material at the edge of continental plate.

crust never becomes more than about 200 the magma erupts from volcanoes as lava
million years old before it is subducted. and pyroclastic fragments, which create new
continental rocks as they cool.
Continents, because they are lighter, are
not usually subducted. This means they can When the continents are pushed up above
be any age, from brand new to incredibly sea level by the subducting oceanic plate,
ancient. There are several places on Earth, they become subject to weathering and
including Scotland, Scandinavia, Siberia, erosion. These processes create sediments
Canada and Australia, where some rocks which collect and are compacted into sedi-
are over 3 billion years old (only 1.4 billion mentary rocks, laid down on the continents’
years younger than the Earth itself). fringes in shallow seas.

Continental rock accumulates over time. It is Oceans and Seas
created by two processes related to subduc-
tion (see Diagram 3.3). The terms ocean and sea have di erent
meanings for geologists. An ocean is
First, some of the subducting oceanic plate underlain by oceanic crust, while a sea
may be scraped off as the plate descends. lies over continental crust. The low-lying
Such ‘rescued’ oceanic rock can be found portion of a continental plate beneath
in a few places in the Alps, including near the sea is called a continental shelf.
Zermatt.
Continental crust may extend hundreds
Second, the subducting plate drags water of kilometres below sea level, but is dis-
down with it, releasing it below the plate tinguished from oceanic crust by the
where it reduces the melting temperature nature of the tectonic plates. Oceanic
of the rocks, creating molten magma. Since crust is thin and dense, while continen-
magma is less dense than cool, solid rocks, tal crust is thick and less dense, because
it rises towards the surface, melting some of they are created di erently (see page 22).
the surrounding rocks as it goes. Eventually

23

The Alps, A Natural Companion | Area Notes

Roc de la Pêche Petit Mont Blanc Dents de la Porte a
Limestone Gypsum Limestone

Photo 8.18 | Petit Mont Blanc is formed of a mass of gypsum and surrounded by limestone and dolomite.

The Vanoise even has a mountain peak, also include some black schists with plant
Petit Mont Blanc, which stands between fossils, and some coal measures (hence the
two peaks of limestone and dolomite but is name Houillère – ‘coal mine’). These sedi-
made entirely of gypsum. The name refers mentary rocks were metamorphosed during
to the fact that the gypsum is white and has the Alpine mountain-building episode.
nothing to do with its famous namesake. There are also some basement crystalline
rocks which were originally metamor-
The third zone is known as the Houillère and phosed more than 300 million years ago
is made up of sedimentary rocks originally and then again during the Alpine mountain-
laid down in the Carboniferous and Permian building episode.
Periods (between 350 and 250 million years
ago). These were mainly sandstones but

94

BASEL Rhine 9. The Swiss Alps

Bodensee

BREGENZ

Weissenstein ZURICH Säntis

Vorarlberg

Jura MassiflCarNTFêMeRtenLoAidGgdanNeeErtDeCNEôElVeAdLAaeCkiBgheCauaGhusiLleasmleLMenemaAsereoouoinsvgRntLsanuMaBaaiilkxllncoDeaeBMisnnnNnelRcMSeeatoneowMununticdsiagchtsesiâsdNssDtMiMuMefCeolioautolterucnetnlhrtilmtagâRnntahAdeyôyBolBneEslDeLautMRaanerNauncthttIDKtenWeeaurtrbneSehfZoriWdroesuulesrarnIrnhmrkTssnoepZtaerEneiJtntnuRtgzneALAgllAfaNFralaMaDirGnEuuMöGirhlghionaonetosctrdrhsrnhLianefUrldwCMEaaRlsdsNifFEurSkacPMhaGswsyrtoyhzsesnITGAlaLSYarrudTosönaAdGliepopsaRrSkhpilüngeenLIECHTENSTEIN Engadine

Graubünden Swiss
National Park
Piz Quattervals
Val Grande Piz da
l’Acqua

Pass
Piz Bernina

Valtellina

Arve Lake Maggiore Lake Como

BaugesSubalpine Chain Massif

Albertville Monte Rosa

Periadriatic Line

Map 9.0 | The Swiss Alps.

9. The Swiss Alps

Grindelwald Area on the northern edge of the Aar massif. Both
Jungfrau (4,158m) and Mönch (4,107m)
Overview exceed 4,000 metres and the North Wall

The area around Grindelwald contains some (Nordwand) of the Aar massif is one of the
of the best-known Alpine scenery, including most impressive rock structures in the Alps.
one of the most famous peaks, the mighty
Eiger, whose notoriously dif�icult north face Although the Eiger is only 3,967 metres in
(Eigerwand) was �irst climbed in 1938. height, it dominates the view of the great
northern �lank of the Aar massif from Kleine
The Eiger is one of a trio of impressive Scheidegg to Grosse Scheidegg, 14 kilome-
peaks within a larger group of mountains tres to the north-east.

95

The Alps, A Natural Companion | Area Notes

Summit of Eiger M nch Jungfrau
the Eiger Glacier (4099m) (4158m)
The classic
ascent route Eroded former
Eiger Wall glacial channel
Station

Photo 9.1 | The North Face of the Eiger and the classic ascent route. Photo 9.2 | The North Wall (Nordwand) of the Aar massif.

A cogwheel train from Grindelwald calls at Formation

Kleine Scheidegg before entering a tunnel The Aar massif, like the sedimentary rocks
to its north (with the exception of some
carved through the Eiger (complete with minor klippen of Penninic rock), is part of
the Helvetic tectonic unit and originated in
viewing windows) and climbing up to the the Helvetic realm.
Jungfraujoch col (3,466m) between Jungfrau
and Mönch, giving tourists an easy trip to
the snow-covered reaches of the Aar massif.

Ancient metamorphic basement rocks (gneiss) Windgallen
Alpine intrusions (granite)
Helvetic sedimentary rocks (limestone & mudstone) Aar Massif Andermatt Rhine Valley
Penninic rocks Gotthard
Penninic thrust line (barbs point to the direction Furka Pass Massif
from which the thrust is coming)

Grindelwald
Eiger
Jungfrau

Rhône Valley

Brig

Map 9.1 | The geology of the Aar and Gotthard massifs.

96

9. The Swiss Alps

Like the Mont Blanc massif, the Aar massif However, when we look at a tectonic map,
consists largely of ancient metamorphic we can see a major difference between the
rocks – gneiss dating from about 350 million Aar/Gotthard and the Mont Blanc/Aiguilles
years ago and granite from about 300 Rouges massifs, namely that the former are
million years ago. These basement rocks considerably larger than the latter. Though
were subsequently thrust upwards from the their widths are fairly similar (the combined
lower crust of the European continent and Aar and Gotthard massifs are nearly 30 kilo-
are now exposed on the surface. metres wide and the Mont Blanc/Aiguilles
Rouges are about 20 kilometres wide), the
The northern sedimentary rocks, however, Aar massif is well over 110 kilometres long,
formed as the upper crust of the conti- while the Mont Blanc massif is only about
nent, just as the Subalpine Chain sedimen- 50 kilometres long. The size of the Aar and
tary rocks did in the Mont Blanc/Aiguilles Gotthard massifs means that they are more
Rouges area. complex than their south-western coun-
terparts and consist of several mountain
The Aar massif is also similar to the Mont ranges covering a substantial area.
Blanc massif in having a smaller crystalline
massif running parallel with it, the Gotthard The area to the north and north-west of
massif. The Gotthard massif lies on the Grindelwald is another Helvetic tectonic
Aar’s south-eastern �lank, just as the Aigu- unit, the Axen thrust. It contains some
illes Rouges massif lies on the Mont Blanc limited outcrops of limestone but consists
massif’s north-western �lank. largely of detrital sedimentary rocks such

We erhorn Main Helvetic Thrusts – Mudstone
(3701m) and limestone were thrust over the
crystalline rocks of the Aar massif

Aar massif
Crystalline rocks

(gneiss)

Faulhorn Grosse Limestone Me enberg
massif Scheidegg (Early Cretaceous and (3104m)

Late Jurassic) 97

Axen nappe mudstone and limestone
(Tertiary and Middle Jurassic)

Grindelwald
Photo 9.3 | The geology of the North Wall of the Aar Massif in the Grindelwald area.

The Alps, A Natural Companion | Area Notes

as mudstone. These rocks are much less erosion are now disconnected from the main
resistant to erosion than the limestone and Penninic rocks to the south.
crystalline rocks of the Aar massif, so there
is a sharp difference (of about 1,500–2,000 Glacial Features
metres) in the height of the landscape
between the peaks of the Aar massif and The Aar massif is home to the Aletsch
those of the Axen nappe massif. Glacier complex, the largest single glacier
system in the Alps, which covers over 80
Some substantial landslides, Imberg and square kilometres and is currently about
Gummi, are visible in these softer rocks just 23 kilometres in length (in 1870 it was 3.2
north of Kleine Scheidegg on the Lauber- kilometres longer). The accumulation area
horn/Tschuggen/Männlichen ridge. The and junction of several glaciers feeding into
track from Kleine Scheidegg to Männlichen the Aletsch Glacier can be observed from
curves into one of these landslide areas, the Jungfraujoch. This con�luence of several
Imberg, giving excellent views of the back glaciers (Grosse Aletsch�irn, Jungfrau�irn,
scar and the hummocky landscape created Ewigschnee�irn and Grünegg�irn) is known
by the collapsed material (see pages 56–57). as Konkordiaplatz and the ice here is about
950 metres deep.
The rocks of the Axen nappe have under-
gone intense thrusting and folding to create The tip of the glacier can be seen by ascending
some exceptionally dramatic rock structures from the Upper Rhône Valley to viewpoints
which can be seen on the Faulhorn massif. on Moos�luh, Bettmerhorn and Eggishorn.

Further north and west, on the outer edges Smaller glaciers, such as the Eiger Glacier
of the Alpine area, there are some klippen and the Upper and Lower Grindelwald
(see page 41) which are the isolated remains Glaciers, �low northwards between the
of Penninic thrusts which once would have main peaks of the massif. These glaciers are
covered all the Helvetic rocks (both the crys- visibly shrinking; obvious signs of their con-
talline and the sedimentary rocks) but due to traction include rockfalls (see page 66).

Photo 9.4 | The Faulhorn massif. Photo 9.5 | Abandoned moraine on the melted portion of the Eiger
Glacier (top left).
98

9. The Swiss Alps

Photo 9.6 | The accumulation zone of the Aletsch Glacier seen from Jungfraujoch.

Near to Grindelwald, in the Lauterbrun- power to create the dramatic vertical valley
nen Valley, is one of the most impressive sides. Today the Se�intal glaciers have all
U-shaped glacial valleys. The narrow valley melted and glacial retreat has left the valley
was carved out in the height of the last ice ice-free, though Tschingel�irn/Kander�irn,
age by several glaciers from the Se�intal, Tellinggletscher/Inner Talgletscher and the
Lauterbrunnen and Kleine Scheidegg areas,
which converged and combined their cutting Breithorngletscher are still active glaciers in

the upper Lauterbrunnen area.

Photo 9.7 | Lauterbrunnen – a classic U-shaped glacial valley.

99

The Alps, A Natural Companion | Area Notes

Photo 9.8 | The Matter Valley with Zermatt in the centre.

Zermatt Area Few of the tens of thousands of visitors to
Zermatt and the surrounding area are aware
Overview that the Matterhorn, possibly Europe’s most
famous mountain, is actually made largely
The Swiss Alpine town of Zermatt, located from rocks derived from the African con-
towards the head of the Matter Valley (Mat- tinent and from an ocean that used to lie
tertal), is one of the most popular tourist between the African and European con-
locations in the Alps, largely because it sits tinents. To �ind rocks derived from the
at the foot of the Matterhorn. The Matterhorn European continent proper, one has to look
is one of the Alps’ most iconic mountains due at the base of the Matterhorn rather than its
to its classic, pyramidal mountain shape. It is shapely middle and upper reaches.
also one of the highest mountains in the Alps,
with a summit height of 4,478 metres, which The Matterhorn is on the Swiss–Italian
is a massive 2,862 metres above Zermatt. border, and is called Monte Cervino in Italian

African
continental

rocks

Oceanic
rocks

European continental European continental
rocks rocks

Photo 9.9 | The Matterhorn (peak in the meadows) is famous for its Diagram 9.1 | The Matterhorn is mainly made up of rocks from the
striking pyramid shape. Its four sides face north, south, east and west. African tectonic plate thrust onto rocks of the European plate.

100

9. The Swiss Alps

Ma erhorn
(4477m)

Dent Blanche Obergabelhorn Zinalrothorn Weisshorn
(4356m) (4062m) (4221m) (4505m)

Dent Blanche nappe Triassic
sedimentary
Ocean oor rocks and schist
rocks

Photo 9.10 | Geology of the Zermatt area. ones, created as the ocean �loor separating
Europe and Africa was crushed, along with
and Mont Cervin in French. The border runs the marginal continental seas of the African
along the skyline seen in Photo 9.14 (page continent and vast areas of the African crys-
103), above the small glaciers that feed into talline basement rocks.
the impressive Gorner Glacier.
Two large areas of crystalline klippen, the
Formation Dent Blanche nappe complex and the Monte
Rosa nappe complex, cover much of the area
The Zermatt area is dominated by three around Zermatt. The Dent Blanche nappe
major sets of rock types; two of them are in the north-west of the area includes the
part of the Upper Penninic nappes (or Matterhorn and several other peaks which
thrust complexes) sitting on top of the piles reach well over 4,000 metres – Dent Blanche
of general Penninic thrusts, and the third is itself (4,356m), Obergabelhorn (4,026m),
part of a klippe from the East Alpine realm
in Africa. The upper nappes are the earliest

Weisshorn Continental seas rocks (sedimentary rocks)
Ocean oor rocks (ophiolites)
Dent Blanche Allalinhorn Dent Blanche nappe Crystalline
Monte Rosa nappe basement rocks
Matterhorn Zermatt Crystalline rocks
Penninic rocks

Dufourspitze

Map 9.2 | Geology of the Zermatt area.

101

The Alps, A Natural Companion | Area Notes

Zinalrothorn (4,221m), and Weisshorn the Zermatt area is their greenish colour,
(4,505m). The Monte Rosa nappe lies to the but in some instances traces of the curved
north-east of the area and has its own high shapes of the pillow lavas can also be dis-
peaks, including Täschhorn (4,491m). cerned even though they have undergone
metamorphosis.
The crystalline rocks of both the Dent
Blanche nappe and the Monte Rosa nappe Some of the big peaks of the area are
date from around 250 million years ago and made up of ophiolites including Alphubel
consist mainly of gneiss, with some granites. (4,206m), Allalinhorn (4,027m), Rimp�is-
Separating these crystalline nappes are two chhorn (4,199m) and Strahlhorn (4,190m).
other sets of complex rock types, dating
from between 220 and 120 million years Both the ophiolites and the sedimentary
ago. One set consists of a variety of rocks rocks, including the Bündner schist, are
created in the Triassic Period from �ine softer than the crystalline rocks which form
sediments laid on top of ocean �loor rocks. the high peaks. The sedimentary rocks are
These hardened into sedimentary rocks and easily eroded away and form the valley areas
include a rock formation known as Bündner and slopes around Zermatt. Only three major
schist (German: Bündnerschiefer, French: summits in the area – Oberrothorn (3,414m),
schistes lustrés). Unterrothorn (3,104m) and Mettelhorn
(3,406m) – are made up of these rock types.
The rocks of the other set, created as new
ocean crust expanded, are called ophio- It is thus not surprising, given the complex-
lites. Ophiolites are ocean crust rocks that ity of its geology, that the Zermatt area has
have been thrust up by mountain-building peculiarities, including the fact that the
processes. In the Zermatt area, they consist Matterhorn, one of Europe’s most iconic
largely of three types of rock – pillow mountains, is built of rocks from the African
lavas, basalt dikes and gabbro. The key continent and from an ocean that once lay
distinguishing feature of the ophiolites in between Africa and Europe.

Photo 9.11 | Bündner schist Photo 9.12 | Ophiolite

102

9. The Swiss Alps

Monte Täschhorn Alphubel Allalinhorn Rimp schhorn Stockhorn Strahlhorn
Rosa nappe (4491m) (4206m) (4027m) (4199m) (2532m) (4190m)

(gneiss)

Ocean oor rocks
(ophiolites)

Monte Rosa nappe
(gneiss and schist)

Ocean oor rocks Triassic
(ophiolites) sedimentary rocks

Photo 9.13 | Mountains and geology looking north-east from Gornergrat.
Glacial Features

The Zermatt area is also renowned for its Gorner Glacier is about 12 kilometres in

glaciers. The Gorner Glacier complex is the length today, but has shrunk by about 2.5
kilometres in the last 150 years as a result
second largest glacial area in Switzerland, of global warming. On average it retreats
covering about 57 square kilometres. The

Zwillings Schwarze Breithorn Unterer Theodule
Glacier Glacier Glacier Glacier

Glaciers now
disconnected from
the Gorner Glacier

Gorner Glacier
Photo 9.14 | Surface stream indicating melting on the surface of the Gorner Glacier.

103

The Alps, A Natural Companion | Area Notes

Gorner Glacier Zwillings
(upper) Glacier
Abandoned Grenz Glacier
moraines Gorner Glacier

Photo 9.15 | Abandoned moraines indicate the previous level of the glaciers.

about 30 metres per year, though in 2008 previously fed directly into the Gorner
it retreated a record 290 metres. The main Glacier have now become disconnected
glacier is now about 200 metres lower than from it, including the Breithorn, Trift, and
it was in 1850; this can clearly be seen on Unterer Theodule Glaciers, as well as the
the valley walls above the glacier. upper reaches of the Gorner Glacier itself.
The main feed into the Gorner Glacier is now
Due to the reduction in the size of the Gorner the Grenz Glacier (border glacier).
Glacier complex, several of the glaciers that

Photo 9.16 | The upper section of the Gorner Glacier (the tongue of ice in the centre) is no longer continuous with the lower section.

104

9. The Swiss Alps

Photo 9.17 | A rock glacier in the Quattervals area of the Swiss National Park.

105

The Alps, A Natural Companion | Flowers

Mountain avens in bloom.

FSECLTOIONWIII ERS

124

12. Life in the Alpine Zone

Photo 12.0 | View of a classic treeline.

12. Life in the Alpine Zone

Despite the apparently inhospitable The term ‘alpine’ is a well-established and
mountain environment with its extreme useful description for any plant that is found
temperatures, high levels of rainfall and growing above the natural treeline (see
many months of blanket snow cover, the Photo 12.0). In the Alps the treeline is more
European Alps are renowned for their strongly determined by latitude and aspect
�loral diversity and brightly coloured alpine than altitude. The warmer, south-facing
meadows. There are, in fact, many beautiful slopes of a mountain receive greater levels
and distinctive alpine species, which have of solar radiation and enjoy a comparatively
successfully adapted to the wide variety higher treeline than the colder, more shaded
of habitats, rock types and microclimates northern aspects (see Diagram 12.1, page
present in the Alpine mountains. 126).

125

The Alps, A Natural Companion | Flowers

Some of the plants found above the treeline to store sugars and provide good anchor-
are found exclusively at this level, but others ing. There are very few annual and short-
can also be seen �lowering at lower alti- lived plants in mountain ranges around the
tudes. In total, the European Alps are home world; long life appears to be an essential
to over 600 truly alpine species which exist strategy to ensure the long-term survival of
exclusively above the forest limits. a species. Alpine plants generally vary from
small perennial herbs and low-lying, pros-
In order to appreciate the diversity of these trate shrubs to compact cushion-forming
alpine �lowers, we must �irst understand plants, all of which demonstrate an ability
the impact of the environment in creating to cope with the extreme climate.
their many modi�ications and adaptations
and investigate the relationship between Reproduction is also an important aspect of
climate, soil and geology in determining plant life and plants have adapted in many dif-
their distribution. ferent ways to reproduce both sexually and
asexually in the alpine environment. These
Alpine �lowers tend to be small but have fascinating mechanisms are explained in more
large, well-developed root systems able detail later in this chapter (see page 131).

On the highest summits, only North South
a few mosses and lichens are

hardy enough to survive

Plants growing above the 2800m HIGH ALPINE Zone 3000m
treeline are called alpine 2300m Moss and lichens
plants, but some may also 2500m Warmer, south-facing slopes
grow at lower altitudes ALPINE Zone receive greater solar radiation
Alpine meadows
Treeline and have a comparatively
(the highest altitude where SUBALPINE Zone higher treeline
Coniferous forests
trees can grow) MONTANE Zone 1500m
Cooler, north-facing slopes
receive less solar radiation Mixed forests
and have a comparatively

lower treeline

1300m

800m 1000m
SUBMONTANE Zone 500m
Deciduous forests

300m

Diagram 12.1 | Illustration of the e ect that aspect has on the distribution of plants in relation to the altitude at which they can grow.

126

12. Life in the Alpine Zone

The Origins of Alpine Plants snowbell, St Bruno’s lily, rampion and ade-
nostyles families whose entire distributions
Alpine regions around the world are often are geographically restricted to the Alps.
considered to be biodiversity hotspots.
Almost all the plant groups found on Earth The formation of the Alps began during the
are represented in these mountainous areas. Tertiary Period when Central Europe was
Some plant families, such as daisy, heather largely under an ancient ocean known as
and true grasses, occur in abundance the Tethys Ocean. Many of the world’s major
across all alpine regions; families such as tectonic plates were closely aligned; Scan-
gentian are also widely distributed around dinavia was connected to Greenland and
the globe. Other families have evolved to North America, and these were linked to
have a narrow distribution in a particular Central and Southern Asia by land bridges.
geographical region and are referred to
as endemic to that area. Such species are It is thought that the �irst plant colonists
highly represented in alpine regions, con- of the Alps originated from neighbouring
tributing greatly to their �loral diversity. mountains in the Balkans, Carpathians,
It is estimated that the European Alps are Apennines and Pyrenees. These mountain
home to 400 endemic alpine species which ranges already had high mountain plants
are either relicts from once widespread through past exchanges with massifs and
species or newly evolved species that haven’t highlands in Asia and Africa. The treeless
had the ability or time to spread their seed grassland environment (steppe) of Central
and colonise new areas. Common groundsel, Asia had a similar climate to the Alps with
for instance, is widely naturalised around extreme temperatures, limited humidity and
the globe, but its close relative one-headed strong sunlight. The steppe plants therefore
groundsel dwells in just a few valleys in the felt at home at altitude in the emerging Alps.
Alps. Other examples of endemism are the
Amongst the alpine �lowers known to have
Photo 12.1 | Alpine adenostyles is an endemic alpine species. migrated west from their ancestry in Central
and East Asia are columbines, gentians,
alpenroses, primroses and rock jasmines
(see Photo 12.2). The Mediterranean basin
and North African mountains are two other
distinct geographical regions of ancestral
origin for Alpine �lowers, including bell-
�lower, spring crocus, campions, toad�laxes
and globularia. North America also had
links to Eurasia through a land bridge which
allowed the emigration of plants from North
America during the last ice age. The well-
known and ancient medicinal plant arnica
originates here, along with alpine aster,
goldenrod, bearberry and alpine �leabane.

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At the end of the Tertiary Period, 2.5 million
years ago, the global climate began to cool
with the onset of the Quaternary Ice Age.
Alpine glaciers expanded and the Scandi-
navian ice sheet grew southward, covering
vast stretches of Europe. Glaciations do not
remove alpine �lora but restrict their distri-
bution to refugia called nunataks (from Inuit
nunataq) above or between ice streams.

During the Pleistocene Era there were an
estimated twenty glacial episodes. The last
glacial episode ended some 12,000 years ago
and was followed by a widespread retreat of
glaciers. This changing global climate had
a huge effect on the distribution of alpine
�lowers. Some species became extinct and
others were isolated, whilst new species
were able to migrate to the alpine region.

The widespread distribution of purple saxi-
frage, for example, across both the Arctic and
the Alps is evidence of the glacial advance
theory. Other alpine �lowers with origins in
Scandinavia include dwarf willow, glacier
crowfoot and mountain avens. The iconic
edelweiss, a migrant to Europe from the
highlands of Asia, travelled along cool, low
altitude corridors during the early postgla-
cial period. The highlands of Asia are home
to over 50 species of edelweiss and are a
centre of diversity for many of the �lower
groups that have migrated from there.

This distribution pattern illustrates the sig- Photo 12.2 | Many of the owers in the Alps originate in distant
ni�icant in�luence geographical isolation has regions of the world that were once connected to Europe by land
upon the evolutionary development of plant bridges. Others migrated along the edge of vast ice sheets. From top:
species. Other major in�luences thought to arnica, purple saxifrage, bald-stemmed globularia and edelweiss.
affect distribution are the constancy of the

environment, genetic variability and repro-

ductive strategy. Our understanding of these

processes remains far from complete.

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12. Life in the Alpine Zone

Photo 12.3 | Low-lying plants are a common sight in the Alpine environment. Dwarf shrubs such as mountain avens have woody stems and are
found carpeting rocky gardens, especially in limestone areas.

Alpine Growth Forms plant of only a few centimetres in height may
in fact have a root system extending several
It is a striking phenomenon that all alpine metres in length, providing good anchorage,
�lowers, regardless of their origin, closely water storage, and access to scarce water
resemble each other in their growth forms. and mineral resources.
Alpine plants have adopted similar designs,
but differ hugely in appearance from their Dwarf Shrubs
lowland relatives. This is a good illustration
of the concept of convergent evolution – Dwarf shrubs are low-lying or prostrate in
plants genetically adapt to grow in a similar nature, often carpeting the ground. They
way despite being from unrelated ancestral have permanent woody stems and are gen-
origins, because they are shaped by their erally the longest-lived alpine plants, but
harsh mountain environment. since the growth rate of woody tissue is very
slow they do not dominate alpine communi-
Plant growth forms in the alpine zone can be ties, despite the advantages of their growth
categorised into a number of distinct groups form. Common examples are dwarf willow,
which we will discuss below, but it is impor- mountain avens and trailing azalea.
tant to mention one striking characteristic
common to most alpine plants, namely their Herbaceous Perennials
stunted growth. Nanism, or low growth, has
many advantages and allows plants to absorb Perennial plants live for over two years and
ground heat, avoid drying winds, and get make a signi�icant contribution to the overall
protection from overlying snow. An alpine diversity of �lowering plants. Short-lived

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annual plants on the other hand are very
uncommon in the alpine environment. Their
survival requires that they complete seed
germination and seed production in a single
year which is a precarious strategy in such
extreme environmental conditions.

Many perennials have very long lifespans;
they often live for hundreds of years. We
can categorise them into three main groups
– grasses (including rushes and sedges),
cushion plants and rosettes. Perennials
can be deciduous, dropping their leaves in
autumn, or evergreen, retaining their foliage
throughout the year.

Tussock Grasses

The majority of grasses, sedges and rushes
in the alpine zone form tussocks and appear
in dense clusters. New shoots grow at
their edges by means of vegetative growth
and they reproduce through this method,
forming dense tufts of shoots. These plants
are often found on poor soils or stable
rocky habitats, and include mat-grass and
cottongrass.

Cushion Plants

These plants form a dense, rounded canopy Photo 12.4 | Plant growth forms in the alpine environment exhibit
with numerous tightly packed leaf rosettes distinct patterns. From top: Mat-grass showing tussock-forming
sheltering the stems beneath. The dense growth; moss campion with cushion-shaped growth; spring gentian
canopy is a very effective heat trap and also with tightly packed leaf rosettes, and lichen growth on bare rock.
provides a moist environment, insulating
the plant from the severe climate. Cushion
plants are characteristic of the high alpine
zone where the climate is most severe and
are often found in stable rocky places where
soils are limited. Typical cushion plants found
at these high altitudes are moss campion,
Swiss rock jasmine and king of the Alps.

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12. Life in the Alpine Zone

Photo 12.5 | Spring pasque ower appears shortly after the snow melts, its owers fully opening for a short time in the late morning sun.

Rosettes liverworts (bryophytes), lichens, and non-

The leaves of these plants form compact, photosynthesising organisms such as fungi.
�lat, grounded spirals. They are a very
Reproduction
common growth form and most frequently

encountered in alpine grasslands. Many Floral diversity and plant growth forms have
have thick, deep taproots and tall �lowering been mentioned previously but we have yet
stems. Among the many species demonstrat- to touch on the mechanisms by which plants
reproduce. Successful reproduction, trans-
ing this growth pattern are starry saxifrage, mitting genetic material to future genera-

least primrose and alpine dandelion.

Succulents tions, is the ultimate aim of all living things.
The evolutionary advantage of sexual repro-

These specialist drought-tolerant plants are duction by cross-breeding and recombining

found in the driest and most inhospitable the genes of two parent plants in their off-
environments because they are able to store spring has clear bene�its for the long-term

much-needed water in their leaves or stems. survival of the species.
Their swollen, �leshy form makes them good
However, �lowering and producing seed
at storing water and also reduces water loss. through sexual reproduction is very energy-

Cryptogams expensive for a plant and far more pollen
and seed are produced than are ever used.
These desiccation-tolerant plants are �lower- The pressures of life in the alpine environ-
less, but they are alpine specialists and can ment with its short growing season, low air
be found in the most inhospitable mountain and soil temperatures, drying winds, strong
environments, where �lowering plants radiation and nutrient-poor soils make this
cannot survive. The term ‘cryptogam’ means strategy a costly one, which is abandoned by
‘spore-bearing’ and includes mosses and some species altogether.

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The Alps, A Natural Companion | Flowers

Despite all these environmental dif�icul- develop before it can be dispersed. Many
ties, brightly coloured �lowers proliferate �lowers have adopted a method to maximise
during the brief summer months as insects the sun’s radiant energy. Bright, parabolic,
go about the business of pollination. Some disc-like �lowers enable maximum energy
alpine �lowers appear early in the season, capture from the sun, as does sun tracking
soon after snow has melted. Species like (heliotropism), a phenomenon whereby
spring pasque�lower commonly appear �lowers follow the sun’s path across the sky.
within days of snow melting in the warm
spring sunshine (see Photo 12.6). Some Reproduction Without Sex
plants, such as snowbells, even appear to
melt snow. They burn fuel, stored since the Many plants are capable of reproducing
previous summer as starch in their fattened without the need for sex. Non-sexual or
leaves, generating heat as they send their asexual reproduction is usually performed
shoots up to the light. Their �lower buds, either by vegetative reproduction or
having been preformed in the previous apomixis. Vegetative reproduction is where
season, burst out rapidly, ready to develop plants produce an identical clone of them-
into a mature �lower. selves from a vegetative part of the plant,
A wide range of insects aid in cross-pollina- usually the stem or root. Apomixis is the
tion, from butter�lies and beetles at lower formation of seed without the involvement
alpine levels to bees and �lies which become of fertilisation through pollination. Despite
more important at higher altitudes. Each the strong evolutionary case for sexual repro-
�lower may attract a range of pollinators; duction, strategies for asexual reproduction
edelweiss, for example, receives pollina- have short-term survival bene�its and can
tors from 29 insect groups, most of which also have signi�icant long-term bene�its too.
are types of �lies. Once the �lower has been
pollinated, time is short, as the seed has to Clones – The Secret to a Long Life

Photo 12.6 | Six-spot burnet moths gathering nectar from a round- Vegetative or clonal reproduction is very
headed thistle and helping to pollinate the owers in the process. common in alpine plants and involves frag-
mentation of the parent plant. It is estimated
that more than 80% of all alpine plants are
clonal. This is a low-cost strategy in terms of
energy and is more likely to lead to success
in making an identical replica of the parent
plant. The cold climatic conditions and short
growing season in the Alps inhibit growth
and thus favour vegetative reproduction.
There are many forms of clonal growth
but it is important to mention here that
clonal growth has other bene�its besides
compensating for the dif�iculty of sexual

132

12. Life in the Alpine Zone

Clonal Growth

Tussock Grasses
These form dense clusters of shoots, pro-
ducing new shoots at the edges; e.g. red
fescue and mat-grass.

Stoloniferous Grasses
These have below-ground runners
(stolons) from which new shoots appear;
e.g. woodrushes.

Mat-forming Herbs
These spread outwards, disintegrating
from the middle. The outward growth
takes root as the plant spreads; e.g.
speedwells and mountain everlasting.

Stoloniferous / Rhizomatous Herbs
Often seen as isolated shoots or groups
of shoots connected by over or under-
ground runners well suited to life on
unstable screes; e.g. fairy’s thimble and
alpine toad ax.

Dwarf Shrubs
These woody-stemmed, creeping plants
develop clonal fragments (sub-units)
which grow roots (adventitious roots)
from a stem rather than a root; e.g.
mountain avens and least willow.

Photo 12.7 | Forms of clonal growth. From top: Tufted hair grass with classic tussock-growth grass, mountain everlasting forming thick
mats, alpine toad ax with over-ground runners (rhizomes) connecting shoots, the creeping, woody stems of retuse-leaved willow from
which new roots develop, and a sea of Scheuchzer’s cottongrass spreading via below-ground runners (stolons).

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Common valerian is an alkaloid-con-
taining plant whose roots are used as a
natural sedative. Prescribed as a remedy
for insomnia in ancient Rome, valerian tea
is still sold in supermarkets as a soothing
bedtime drink. Valerian also sends cats into
an ecstatic state like catnip does.

The more serious effects of alkaloids are Photo 14.7 | Like many other alkaloid-containing plants,
seen in plants such as monkshood, which monkshood is highly poisonous.
has been used to poison the tips of arrows.
The poison can be absorbed through the
skin and it is therefore very dangerous to
touch the plant. One should also be wary
of another alkaloid-containing plant, white
false helleborine, whose roots have been
used as an insecticide for currant and goose-
berry bushes. This highly poisonous plant
is very similar in appearance to the medici-
nal great yellow gentian and could easily be
mistaken in the �ield.

Photo 14.8 | Some plants look very similar but their active ingredients have vastly di erent e ects on the body. Great yellow gentian (left)
is known to aid digestion and is added to alpine schnapps, whereas the active compounds in white false helleborine (right) are poisonous to
humans.

150

15. Flower Identi cation Guide

Photo 15.0 | King of the Alps at Hohsaas.

15. Flower Identi cation Guide

Using the Flower Identi cation Guide The plants are primarily categorised by
the dominant �lower colour and then sub-
The information provided about each of the divided by �lower shape. This is indicated in
species in this guide is intended to inform the side bar of the page to help you quickly
but not to overwhelm or overburden. The navigate to the appropriate section.
language is kept straightforward and there
is a glossary providing brief explanations Both the common and scienti�ic names
of technical botanical terms (see page 284). are given, as are the botanical families to
There is also a section detailing the struc- which the plants belong. Many common
tures, arrangements and shapes of �lowers names exist across a region where differ-
and leaves (see page 154). ent languages are spoken; for example the
English bilberry, French myrtille, and Italian

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mirtillo all refer to a single species which the vulnerable category of the IUCN Red List
is recorded scienti�ically (in italics) as Vac- despite its abundance in the Alps and the
cinium myrtillus. These scienti�ic names get Rockies, because its entire British popula-
updated from time to time and this book uses tion is con�ined to a few cliffs in Snowdonia.
the most up-to-date versions at the time of
publishing. Botanical families comprise many Species which are rare or have a threatened
species with common characteristics such global status are protected by various inter-
as number of petals or �lower shape. As you national conservation policies and treaties.
become familiar with them, these character- This guide acknowledges those which are
istics will help you to identify related species.
Conservation
Flowering times detail the months when each
�lower is likely to be seen in bloom, though The Habitats Directive
this can vary with altitude and latitude. Plant
height gives a general idea of overall plant The Habitats Directive was adopted
size but, again, this can be affected by local in 1992 and forms an important part
variations in climate and soil. of European Union nature legislation.
It aims to ensure the conservation of
The guide includes each �lower’s altitudinal a wide range of rare, threatened or
range, categorised into four altitudinal zones: endemic animal and plant species.
submontane, montane, subalpine, and alpine Along with the Birds Directive it forms the
(see Diagram 13.1, page 140). It also notes the cornerstone of Europe’s nature conserva-
�lowers’ distribution. Some species have a tion policy and establishes the EU-wide
broad geographical range and can be found Natura 2000 ecological network of pro-
outside the Alps, for example in the British tected areas, safeguarding them against
Isles, the Pyrenees or Scandinavia, so this is potentially damaging development.
intended as a guide rather than an absolute.
The Bern Convention
The habitat section denotes the plants’ pre-
ferred environment. Some species are very The Bern Convention is the European
speci�ic to limestone rocks, for instance, and treaty for the conservation of nature and
this may help in differentiating closely related has been in force since June 1982. It was
species. Other species may be found across the rst international treaty to protect
open woodland, meadows and on rocky both species and habitats, and to bring
ground, so an understanding of geology and countries together to decide how to
soil type is of great bene�it in identi�ication. act on nature conservation and how to
promote sustainable development.
Information is also provided about con-
servation and protection. Some species The Convention on International Trade
may be important locally, even though
their wider population may not be under The Convention on International Trade
threat. A classic example is the Snowdon in Endangered Species of Wild Fauna and
lily, which is listed as a protected species in Flora (CITES) aims to ensure that inter-
national trade in specimens of wild
animals and plants does not threaten
their survival.

152