Elsevier Encyclopedia of Geology

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Engineering Geology

Major construction works depend upon sound site

investigation, which documents the underlying geo-

logical setting and the strengths and behaviours of the

rocks and engineering sols and recognizes hazardous

ground conditions. In the UK alone, over 30% of all

major civil engineering projects are delayed owing to

poor ground conditions. It is essential to carry out

thorough site investigations, using a range of geo-

logical techniques, including mapping and geophys-

ical surveys, as well as committing significant time to

material testing. Consideration of climate is a major

issue, as in Hong Kong, where the failure of tower

blocks has been attributed to the failure of thick trop-

ical soils overlying crystalline basement, coupled with

high rainfall (see Engineering Geology: Overview).

Geology of Waste Management

The urban machine creates an immense amount of

waste, which may be defined as any substance that

constitutes a scrap material, effluent, or unwanted

surplus or any substance or article that requires dis-

posal because it is worn-out or contaminated in some

way. Although there is increasing emphasis on waste

minimization and recycling, it is accepted that there

will always be waste and that a strategy for its

disposal will be required.

Wastes can conveniently be divided on the basis of

whether they are managed (i.e. there is a management

strategy in place to deal with their disposal that is in

line with current practice and legislation) or unman-

aged (i.e. there is no management strategy). Strategies

for dealing with wastes have been based largely on

two concepts: dilute and disperse, or concentrate and

contain (Figure 5). The failure of these strategies

ultimately leads to pollution, which is a by-product

of inadequate waste-management strategies.

The dilute-and-disperse strategy is now largely dis-

credited, because it relies on the potential of a given

environmental setting to dilute the waste materials

and then to disperse them. This has been, and con-

tinues to be, an issue for the dispersal of effluents in

the sea and of gases in the atmosphere, as these natural

systems are becoming choked with inadequately dis-

persed wastes. Concentrate and contain is now seen

as the most viable option, with wastes being concen-

trated, compacted, or shredded where possible, before

being placed in a safe totally enclosed (or ‘sanitary’)

facility. At one level this entails the adequate prepar-

ation of a landfill site; at another, the containment of

radioactive materials in an appropriate repository in

perpetuity.

Contaminated Land

Contaminated land is any area that has been contam-

inated by its past industrial use or by the disposal of

wastes. Contamination is therefore an inevitable eff-

ect of industrialization, and of waste disposal, as it

involves the introduction of materials not naturally

present at a given location. Contaminated land is a big

issue in developed nations, with the decline in heavy

industry and the targeting of former sites of industry

as valuable real estate in inner-city locations. Increas-

ingly, there is a need for adequate assessment of a site –

assessing the type and level of contamination – before

developing a clean-up strategy.

Sanitary Landfill

Employing the principle of concentrate and contain,

sanitary landfills (Figure 5) ensure that appropriate

voids are chosen for landfilling, appropriate contain-

ment strategies are employed in developing the land-

fill (using liners, separating the void into cells divided

by bunds, and capping the site securely), the void is

filled in an economical and organized manner, and

Figure 5 Landfill options: (A) total containment, and (B) slow dispersal. (Reproduced with permission from Bennett MR and Doyle

P (1997) Environmental Geology: Geology and the Human Environment. Chichester: John Wiley.)

30 ENVIRONMENTAL GEOLOGY

the by-products of the decay of putrescible wastes (i.e.

landfill gas and leachates) are removed safely. The

decomposition of wastes by bacteria takes place in

three phases: first, aerobic bacteria break down the

large organic molecules; second, anaerobic bacteria

create simple compounds, such as hydrogen, ammo-

nia, carbon dioxide, and organic acids; and, finally,

the methane-rich landfill gas is created. In practice,

this means that in the early years of a landfill the

amount of gas produced is relatively small, rising

to a maximum in around 20 years. Uncontrolled mi-

gration of this gas can be lethal, as in some cases the

results have been explosive, with gases migrating

through suitable geological pathways, as happened

in 1986 at Loscoe in northern England. Leachates

are dealt with by ponding and removal, in most

cases, and then treated.

Deep Repositories for Nuclear Wastes

The disposal of nuclear radioactive wastes is a diffi-

cult problem, given the ‘geological’ time-scales of the

half-lives of the isotopes of uranium used in the

nuclear-power industry. One option is to concentrate

wastes in a secure surface repository, which can be

monitored to ensure that the multiple walls of the

containment are secure. This obviously requires a

long-term commitment. Over the last few decades,

other options have been considered, including using

a uniform densely crystalline deep-crustal rock body

as a natural repository, which could be sealed in per-

petuity (Figure 6). Lithologies considered have in-

cluded fine-grained tuffs, basalts, and evaporates,

and detailed investigations in the UK and the USA

of the feasibility of sites in Cumbria and Texas, re-

spectively, have been carried out. However, technical

difficulties and political issues have stalled these

geological solutions.

Geology of Natural Hazards

Natural hazards occur on a regular basis, cause dis-

ruption and destruction, and annually lead to large

losses of life under tragic circumstances (see Engineer-

ing Geology: Natural and Anthropogenic Geohazards).

Geological hazards include high-magnitude low-

frequency events (earthquakes, volcanoes, and tsu-

namis) and low-magnitude high-frequency events

Figure 6 Deep-repository option for nuclear wastes, illustrating (A) the current geology, and (B) the geology at some point in

the future with the influx of fresh glacial meltwaters (arrow). (Reproduced with permission from Bennett MR and Doyle P (1997)

Environmental Geology: Geology and the Human Environment. Chichester: John Wiley.)

ENVIRONMENTAL GEOLOGY 31

(such as soil, fluvial, and coastal erosion). Dealing with

both types of event severely tests the local civil-defence

infrastructures, and, with the frequency of disasters

apparently on the increase – with attendant casualties

and economic costs – planning for disaster manage-

ment is a major preoccupation of local authorities.

There are three broad hazard types: atmospheric

hazards, caused by tropical storms, hurricanes, and

droughts; exogenic hazards, such as flooding, coastal

erosion, and mass movement; and endogenic hazards,

resulting from internal Earth processes, such as vol-

canoes and earthquakes. In many cases there can be

considerable overlap between these events, as one can

trigger another. In profiling natural hazards, it is im-

portant to gather data on the magnitude and fre-

quency (including temporal spacing) of the events,

the duration and speed of onset of a typical event,

and the extent and dispersion of the effects. These

issues have to be taken into account in civil-defence

planning strategies, which will identify the risk to life,

property, and the economy.

Risk assessment is an important task and will in

many cases involve a predictive element, although

prediction of earthquakes and volcanic eruptions is

a tricky business, without a simple solution. Hazard

mapping is a significant technique and had been used

to good effect in identifying patterns of eruption in

populated volcanic regions (Figure 7). This, together

with a numerical assessment of the vulnerability of a

given settlement, are important tools in the armoury

of an environmental geologist.

Further Reading

Bailleul TA (1987) Disposal of high-level nuclear waste in

America. Bulletin of the Association of Engineering

Geologists 24: 207–216.

Bell FG (1992) Salt mining and associated subsidence in

mid-Cheshire, England, and its influence on planning.

Bulletin of the Association of Engineering Geologists

29: 371–386.

Bell FG (1993) Engineering Geology. Oxford: Blackwell.

Bell FG (1996) Dereliction: colliery spoil heaps and

their rehabilitation. Environmental and Engineering

Geoscience 2: 85–96.

Bell FG, Duane MJ, Bell AW, and Hytiris N (1996)

Contaminated land: the British position and some case

histories. Environmental and Engineering Geoscience 2:

355–368.

Bennett MR and Doyle P (1997) Environmental Geology:

Geology and the Human Environment. Chichester: John

Wiley.

Figure 7 Volcanic hazard map of Tenerife, Canary Islands.

32 ENVIRONMENTAL GEOLOGY

Booth B (1979) Assessing volcanic risk. Journal of the

Geological Society of London 136: 331–340.

Bryant EA (1991) Natural Hazards. Cambridge:

Cambridge University Press.

Culshaw MG, Bell FG, Cripps JC, and O’Hara M (eds.)

(1987) Planning and Engineering Geology. London:

Geological Society.

Doyle P, Barton P, Rosenbaum MR, Vandewalle J, and

Jacobs K (2002) Geoenvironmental implications of the

underground war in Flanders, 1914–1918. Environmen-

tal Geology 43: 57–71.

Fookes PG and Poole AB (1981) Some preliminary consid-

erations on the selection and durability of rock and con-

crete materials for breakwaters and coastal protection

works. Quarterly Journal of Engineering Geology 14:

97–128.

Gray M (2004) Geodiversity: valuing and conserving abiotic

nature. Chichester: John Wiley.

Gray RE and Bruhn RW (1984) Coal mine subsidence: east-

ern United States. Geological Society of America Reviews

in Engineering Geology 6: 123–149.

Joseph JB (2004) Perception or reality – waste, landfill and

the environment. Geology Today 20: 107–112.

Lumsden GI (ed.) (1992) Geology and the Environ-

ment in Western Europe. Oxford: Oxford University

Press.

McFeat-Smith I, Workman DR, Burnett AD, and Chau EPY

(1989) Geology of Hong Kong. Bulletin of the Associ-

ation of Engineering Geologists 26: 23–107.

Prentice JE (1990) Geology of Construction Materials.

London: Chapman & Hall.

Price M (1985) Introducing Groundwater. London: Allen

& Unwin.

Smith K (1996) Environmental Hazards: Assessing Risk

and Reducing Disaster, 2nd edn. London: Routledge.

Thomas RG (1989) Geology of Rome, Italy. Bulletin

of the Association of Engineering Geologists 26:

415–476.

Waltham AC (1994) Foundations of Engineering Geology.

Glasgow: Blackie.

Williams GM and Aitkenhead N (1991) Lessons from

Loscoe: the uncontrolled migration of landfill gas.

Quarterly Journal of Engineering Geology 24: 191–207.

Woodcock NH (1994) Geology and Environment in Britain

and Ireland. London: UCL Press.

EROSION

See SEDIMENTARY PROCESSES: Erosional Sedimentary Structures; Aeolian Processes; Fluxes and

Budgets

ENVIRONMENTAL GEOLOGY 33

a0005 EUROPE

Contents

East European Craton

Timanides of Northern Russia

Caledonides of Britain and Ireland

Scandinavian Caledonides (with Greenland)

Variscan Orogeny

The Urals

Permian Basins

Permian to Recent Evolution

The Alps

Mediterranean Tectonics

Holocene

East European Craton

S V Bogdanova and R Gorbatschev, Lund

University, Lund, Sweden

R G Garetsky, Institute of Geological Sciences, Minsk,

Belarus

Introduction

The East European Craton is the coherent mass of

Precambrian continental crust in the north-eastern

half of Europe. Across a suture zone between the

North Sea and the Black Sea, that crust meets the

younger, thinner, warmer, and more mobile crust of

western and southern Europe.

The overall area of the East European Craton is

more than 6.7 million km

, including the shelf seas.

Within the East European Craton, Precambrian

crystalline crust is exposed in the Baltic (also Fennos-

candian) and Ukrainian Shields as well as in minor

areas in Belarus and the Voronezh Massif of south-

western Russia. Elsewhere, the craton is covered by

the Late Proterozoic and Phanerozoic sedimentary

deposits of the Russian Platform (Figure 1).

The present state of the East European Craton is

largely controlled by structures dating back to the

time of its formation by the successive collision of

three large, once independent, crustal segments –

Fennoscandia, Sarmatia, and Volgo-Uralia – in the

Palaeoproterozoic, ca. 2.1–1.7 Ga ago. This view

was first proposed in 1993. Until then, the East

European Craton was regarded as a rather uniform

region of numerous minor ‘blocks’ of Archaean crust

set in a matrix of Proterozoic folded belts.

Margins and Borders

Most of the margins of the East European Craton are

characterized by the presence of younger mobile belts

(Figure 1). In the north-west, the Scandinavian Cale-

donides (see Europe: Scandinavian Caledonides (with

Greenland)) form a ca. 1800 km long strongly eroded,

but still up to 15-km thick, pile of large thrust sheets

built up of Early Palaeozoic and Precambrian rocks.

These nappes derive from source areas far to the

present west and were thrust atop the crystalline base-

ment around 450–400 Ma ago. Autochthonous base-

ment fabrics are still perceptible throughout the

Caledonides, while geophysical and palaeogeographi-

cal data indicate that the Pre-Caledonian margin of

the East European Craton may be as much as 400 km

off the Atlantic coast of Scandinavia.

Along the north-eastern margin of the East

European Craton, the Timanide Belt extends between

the Urals and northernmost Norway (see Europe:

Timanides of Northern Russia). It features initial

sedimentation along a passive continental margin,

followed by compression, metamorphism, and

igneous activity due to subduction and collision

650–600 Ma ago.

The eastern limit of the East European Craton is

the Late Palaeozoic Uralide Orogen, which repre-

sents the zone where ancient Europe collided with

Asian terranes 350–300 Ma ago (see Europe: The

Urals). Farther south-west, the margin of the East

34 EUROPE/East European Craton

European Craton was developed in the Neoprotero-

zoic and Early Cambrian due to collision between

the Craton and part of Gondwana. That margin was

subsequently complicated by the uplifted south-

eastern continuation of the Devonian Dniepr–Donets

Aulacogen (the Karpinsky Swell in Figure 1).

The southern edge of the East European Craton

is outlined by the Alpine mountain belts of the

Crimea and Caucasus. In that region, the Scythian

Platform marks a slab of East European cratonic

crust involved in the Alpine–Mediterranean orogenic

process.

Figure 1 The East European Craton in its crustal setting between central Europe and western Siberia. The craton area is marked in

reddish-brown colours. The fainter the tint, the thicker the sedimentary cover. The areas of outcrop in the Baltic and Ukrainian Shields

and the Voronezh Massif can be clearly seen. The cover is also thin in Belarus, but only in a minor uplift is the craton actually exposed. It

can also be seen that the basement is more deeply buried in the eastern part of the Russian Platform than in the west. Between the

eastern region and the basin beneath the southern Baltic Sea is the so-called ‘Scythian Rampart’ of the early geologists, which connects

the Baltic and Ukrainian Shields. The cover is thickest in the Peri-Caspian Basin, where the mottled patterns denote salt-dome tectonics.

Among the large rifts and aulacogens characteristic of the East European Craton, the originally Proterozoic but subsequently rejuven-

ated central Russian and Pachelma systems can be clearly recognized. The latter is immediately north-north-east of the Voronezh

Massif. The rift systems to the west of the Urals and in the south-western foreland of the Timanides can also be seen. Prominent in the

south is the Devonian Dniepr–Donets Aulacogen and its inverted eastward continuation (the so-called ‘Karpinsky Swell’) between the

Scythian Platform and the Peri-Caspian Basin and onwards into Asia. This figure is part of the ‘Carte Tectonique de l’Europe et des

gions Avoicinantes,’ scale 1 to 10 min. IUGS Commission for the Geological Map of the World, 1975 (by courtesy of the CGMW.)

EUROPE/East European Craton 35

In the south-west, the Trans-European Suture Zone

is the limit of the East European Craton. Across

that boundary, the Craton abuts terranes successively

formed during the Caledonian, Variscan, and Alpine–

Mediterranean orogenies. Along the central course of

the Trans-European Suture Zone, palaeontological

data indicate that some terranes in Poland repre-

sent detached slices of the Craton. In northern

Germany, a wedge of East European cratonic crust

has been traced seismically far to the south-west of

the Trans-European Suture Zone.

Crustal Thickness and Magnetic and

Gravity Fields

The crust of the East European Craton is mostly

around 35 km to somewhat more than 40 km

thick. Moho depths of up to 50 km occur particularly

in a wide central area near Moscow, in the south-

west, and in the Ukrainian and Baltic Shields.

Local maxima may even exceed 60 km. Under some

of the Archaean parts of the East European Craton,

cratonic roots in the lithospheric mantle reach down

to 200–250 km.

The most pronounced Moho uplift, to a level of

around 30 km, is associated with the northern part of

the Peri-Caspian Basin, where a thick Proterozoic to

Phanerozoic cover is also present. In consequence, the

thickness of the Precambrian crystalline crust is only

10–15 km in that region.

At the borders of the East European Craton, Moho

depths increase along the Uralides and the Caucasus

collisional belts as well as in the central and southern

parts of the Trans-European Suture Zone. Further

north, continental crust thins markedly towards the

North Atlantic Ocean.

In detail, steep gradients of Moho depth commonly

follow one-time collisional and accretionary plate

and terrane boundaries and, in general, the boundar-

ies between Archaean and Proterozoic crust. How-

ever, in places, the original continental crust has been

thickened by later mafic underplating or thinned by

extension and magmatism.

The East European Craton differs from the neigh-

bouring parts of Europe and western Siberia in fea-

turing numerous belts of strong magnetic anomalies.

These outline the boundaries of the different crustal

units as well as later rifts and some major belts of

granitic and high-grade metamorphic rocks (Figure 2).

The patterns of the gravity field are similar, but

strongly negative anomalies occur only along the

Scandinavian Caledonides and just outside the limits

of the craton along the Carpathian, Crimean, and

Caucasian Alpine–Mediterranean mountains.

Morphology, Topography, and

Sedimentary Cover

Morphologically, most of the East European Craton

forms a vast low-lying plain. Some small-scale broken

topography exists in the shield areas, particularly in

the recently glaciated Baltic Shield. The largest flats,

in contrast, extend towards the south-east, where the

Peri-Caspian depression is largely below global sea-

level (Figure 1). Pronouncedly mountainous areas

occur only in western and northern Scandinavia,

where the Caledonides and their Precambrian base-

ment were uplifted and topographically rejuvenated

during the opening of the North Atlantic.

The cover of the Russian Platform mostly ranges

between some tens of metres and 2 km in thickness

(Figures 1 and 3A). Several rifts and basins, however,

contain sedimentary piles 3–5 km thick, while the

Dniepr–Donets Aulacogen in the Ukraine and south-

western Russia has a fill exceeding 15 km in thickness

(Figure 3B). A general depression of the basement–

cover boundary occurs towards the marginal moun-

tain belts of the Timanides, Uralides, and Caucasus, the

greatest cover thickness of approximately 20 km being

reached in the area to the north of the Caspian Sea.

The covered parts of the East European Craton

comprise several large basins of sedimentation, e.g.

the Moscow, Baltic, and Peri-Caspian basins. These

were largely formed in response to recurrent cycles of

rifting, subsidence, and compression. Maxima of

basin formation and filling occurred during the

Riphean (Meso- to Neoproterozoic), the Early Ven-

dian (terminal Neoproterozoic), the Late Cambian-

Ordovician, the Middle-to-Late Devonian, the

Carboniferous–Permian transition, and the Triassic

(Figures 3–5). Generally, these maxima were related

to orogenies, major plate-tectonic movements, rota-

tions of the East European Craton, and its interaction

with other proto-continents such as Laurentia,

Greenland, and Avalonia.

Large rifts and aulacogens are characteristic elem-

ents of the East European Craton (Figure 6). Many of

the oldest, i.e. of Meso- to Neoproterozoic age, are

associated with the system of Palaeoproterozoic

sutures that arose as a result of the formation of

the craton from several colliding crustal segments.

To this group belong the Pachelma, Volyn-Orsha,

and Central Russian rifts and aulacogens (Figure 6).

Other rifts of that age follow age-province boundar-

ies, while several Neoproterozoic troughs in the Peri-

Urals region were developed on a Mesoproterozoic

passive continental margin. Unlike the Precambrian

rifts, many Phanerozoic rifts, for instance the Dniepr-

Donets Aulacogen, cut sharply across the grain of

the crust.

36 EUROPE/East European Craton

Figure 2 Magnetic anomaly patterns in the East European Craton. In general, these patterns describe very well the tripartite crustal-

segment structure of the East European Craton (cf. Figure 8). In addition, the strongest positive anomalies mark major occurrences of

magnetic iron ores, for example the Kursk magnetic anomaly in the Voronezh Massif and the anomalies indicating the ores of

northernmost Sweden (Kiruna, etc) and the Kriviy Rog ores in the Ukraine. Where sedimentary fillings are very thick in rifts and basins,

ribbon-shaped negative or alternating negative–positive anomaly patterns prevail (e.g. in the Dniepr–Donets and Pachelma Aulaco-

gens and the Peri-Caspian Basin). Moderately positive anomalies are associated with amphibolite to granulite facies metamorphic

belts and some granite provinces, such as the rapakivi massifs and parts of the Trans-Scandinavian Igneous Belt. However, other

rapakivi plutons (Viborg, for instance) have negative anomalies. Similar diversity is also found for the Archaean protocratons. Map by

courtesy of S Wybaniec of the Polish Geological Institute.

EUROPE/East European Craton 37

Rifting in the East European Craton was com-

monly accompanied by within-plate mafic magma-

tism, which, during some periods, e.g. the Devonian,

may have been associated with mantle-plume

upwelling. Among the products are kimberlites (see

Igneous Rocks: Kimberlite) found, for instance, in the

Ukrainian Shield, Voronezh Massif, and Kola Penin-

sula region.

Crustal Segments of the East

European Craton

The Meso- and Neoproterozoic Volyn-Orsha, central

Russia, and Pachelma rifts and aulacogens divide

the East European Craton into three different parts

(Figures 6 and 8). Research during the last 15 years

has demonstrated that these correspond roughly to

three Precambrian crustal segments, each of which

has its own Archaean–Palaeoproterozoic history.

The three segments are Fennoscandia (including

the Baltic-Fennoscandian Shield) in the north-west

and north, Sarmatia (comprising the Ukrainian Shield

and the Voronezh Massif) in the south, and Volgo-

Uralia in the east.

Fennoscandia and Sarmatia both feature Archaean

cores and accreted Palaeoproterozoic juvenile

continental crust, whereas Volgo-Uralia is almost

entirely Archaean but was strongly reworked in the

Palaeoproterozoic.

Fennoscandia

The Fennoscandian crustal segment consists of two

principal parts (Figure 9). In the north-east there is a

large domain of Archaean crust, while the rest of the

segment is made up of Palaeo- and Mesoproterozoic,

mostly juvenile, mantle-derived rocks. These belong

to several successively formed orogenic belts.

The demarcation between the Archaean and Pro-

terozoic regions is fairly sharp, but the edge of the

Archaean has been reworked tectonically and

Figure 3 Sections across the Phanerozoic sedimentary cover of the Russian Platform and adjoining areas. (A) Profile of the eastern

part of the Baltic Sea Depression, showing the disconformities between three different tectonostratigraphic complexes. These

correspond roughly to the three Phanerozoic orogenies that shaped adjoining central Europe and changed the regimes of sedimenta-

tion and erosion within the East European Craton. C, Cambrian; O, Ordovician; S, Silurian; D, Devonian; P, Permian; T, Triassic;

J, Jurassic; K, Cretaceous; Kz, Cenozoic. (B) General seismic section across the Dniepr–Donets Rift Basin. The ends of the section are

approximately 170 km apart, but the middle portion of the profile has been omitted from the diagram. Salt diapirs are shown in blue.

Pc, Precambrian; D, Devonian; C, Carboniferous; P, Permian; T, Triassic; J, Jurassic; K, Cretaceous. Seismic section by courtesy of the

Secretariat of the EUROPROBE Programme.

38 EUROPE/East European Craton

magmatically, and is overlain or overthrusted by

Palaeoproterozoic rock units. Inside the Archaean

domain, however, is the north-west–south-east trend-

ing Late Palaeoproterozoic collisional Lapland–Kola

Orogen, while isotopic data suggest that parts of

the Palaeoproterozoic region in the south-west are

underlain by blocks or wedges of Archaean crust.

The Archaean domain comprises the Karelian Pro-

tocraton, the Belomorian Belt along the White Sea,

several different terranes in the Kola Peninsula, and a

western province extending all the way to the Lofoten

Islands of Norway but partly hidden beneath the

Caledonide allochthon.

The Karelian Protocraton is the largest province of

Archaean crust. It contains a sizable area and several

minor occurrences of igneous rocks older than

3.1 Ga, the oldest zircon ages being about 3.5 Ga.

These rock units are set in terranes dominated by

3.0–2.8 Ga greenstone belts rich in komatiites (see

Igneous Rocks: Komatiite) and juvenile tonalite–

trondhjemite–granodiorite (TTG) granitoids. The

greenstone belts are of several generations and have

been attributed to a number of different geodynamic

settings such as continental rifts, oceanic arcs, and

active continental margins. Remnants of approxi-

mately 2.8 Ga ophiolites are found in the north-

eastern part of the Protocraton. In the literature,

block mosaics as well as large gently dipping crustal

wedge structures are indicated. This suggests

a complex but still largely undeciphered story of

Mesoarchaean continent assemblage. In the Neoarch-

aean, i.e. after 2.8 Ga, volcanism and granitoid mag-

matism continued, producing rocks ranging from

TTG complexes to granites of collisional regimes

and late post-kinematic intrusions.

Similar Neoarchaean developments characterize

the adjacent Kola and Belomorian provinces, but

these lack rocks older than 3.0 Ga. A notable feature

of the Central Kola sub-province is the presence of the

thick but subsequently highly metamorphosed 2.7 Ga

Keivy cover sequence, which is known for its giant

crystals of kyanite, staurolite, and other minerals.

Figure 4 Lithologies of the Cambrian to Silurian rocks along the south-western margin of the East European Craton. The lithofacies

zones are: blue, deep-water pelites; green, lower-shelf calcareous and pelitic rocks; and yellow, shallow-water calcareous rocks. The

brown fields represent areas from which these and similar lithologies have been removed by erosion; red indicates other parts of the

exposed Precambrian crystalline crust. ß Svetlana Bogdanova.

EUROPE/East European Craton 39

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