The glacial series refers to a particular sequence of landforms in Central Europe that were formed during the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

glaciation A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betw ...

beneath the ice sheets, along their margins and on their forelands during each glacial advance.''Die glaziale Serie und glaziale Sonderformen in Schleswig-Holstein''
. Forum Erdkunde, Uni Lünibürg. Accessed on 6 January 2008.

Definition

The term "glacial series" (german: Glaziale Serie) was used as early as 1882 by

Albrecht Penck Albrecht Penck (25 September 1858 – 7 March 1945) was a German geographer and geologist and the father of Walther Penck. Biography Born in Reudnitz near Leipzig, Penck became a university professor in Vienna, Austria, from 1885 to 1906, ...

initially for the northern

Alpine Foreland The Alpine Foreland, less commonly called the Bavarian Foreland,Dickinson, Robert E (1964). ''Germany: A regional and economic geography'' (2nd ed.). London: Methuen, pp. 585-586. . Bavarian Plateau or Bavarian Alpine Foreland (german: Bayerisches ...

. Later the term was expanded and used to refer to the Scandinavian glaciation region. The elements of an ideal and complete glacial series are: * a

ground moraine A moraine is any accumulation of unconsolidated debris (regolith and rock), sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a glacier or ice shee ...

with a tongue-like basin, the ''

Zungenbecken A ''Zungenbecken'', also called a tongue basin or tongue-basin, is part of a succession of ice age geological landforms, known as a glacial series. It is a hollow that is left behind by the ice mass, as the snout of the glacier (German: ''Glets ...

'' * a

terminal moraine A terminal moraine, also called end moraine, is a type of moraine that forms at the terminal (edge) of a glacier, marking its maximum advance. At this point, debris that has accumulated by plucking and abrasion, has been pushed by the front edge ...

chain that lies in an arc around the ''Zungenbecken'' * a gravel field or sandur outwash plain in front of the terminal moraine chain * a

glacial meltwater valley An ''urstromtal'' (plural: ''Urstromtäler'') is a type of broad glacial valley, for example, in northern Central Europe, that appeared during the ice ages, or individual glacial periods of an ice age, at the edge of the Scandinavian ice sheet and ...

, the ''Urstromtal'', through which meltwaters from the glacier flowed away. The term "glacial series" is restricted to landforms created by glaciers and classified by

geomorphological Geomorphology (from Ancient Greek: , ', "earth"; , ', "form"; and , ', "study") is the scientific study of the origin and evolution of topographic and bathymetric features created by physical, chemical or biological processes operating at or n ...

rules, as opposed to the

glacial A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betw ...

sediments Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand a ...

and

sedimentary rock Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

s associated with glaciers and classified by their geological features. A complete glacial series is formed when the edge of the ice sheet remains static for a long time and is not destroyed again by a further advance of the ice mass.

Glacial series in the Alpine Foreland

The Alpine

glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its Ablation#Glaciology, ablation over many years, often Century, centuries. It acquires dis ...

s, that formed a network of ice streams during the high points of the

ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...

s, repeatedly flowed beyond the boundary of the Alps and advanced into the

. There they formed vast foreland glaciers. In this Alpine Foreland glaciation, Penck identified a number of landforms: the ground moraines, the ''Zungenbecken'', the terminal moraines and the gravel plains in front of them. The bowl-shaped basins, which were formed by the scouring of the ground by the glacier, were called ''Zungenbecken'' ("tongue basins"), because the tongue or snout of the glacier was once located here.''Geologisches Wörterbuch''. H. Murawski, Enke Verlag, Stuttgart 1983, , p. 249 In these basins, if there was no outlet,

glacial lake A glacial lake is a body of water with origins from glacier activity. They are formed when a glacier erodes the land and then melts, filling the depression created by the glacier. Formation Near the end of the last glacial period, roughly 10,0 ...

s (''Gletscherrandseen'' or ''Zungenbeckenstauseen'') were formed during the retreat of the glacier. There is a number of lakes of this type in the

Salzkammergut The Salzkammergut (; ; bar, Soizkaumaguad, label=Central Austro-Bavarian) is a resort area in Austria, stretching from the city of Salzburg eastwards along the Alpine Foreland and the Northern Limestone Alps to the peaks of the Dachstein Mounta ...

, for example. Typical landforms within the ''Zungenbecken'' of the Alpine Foreland are

drumlin A drumlin, from the Irish word ''droimnín'' ("littlest ridge"), first recorded in 1833, in the classical sense is an elongated hill in the shape of an inverted spoon or half-buried egg formed by glacial ice acting on underlying unconsolidated ...

s, but there are rarely any

tunnel valley A tunnel valley is a U-shaped valley originally cut under the glacial ice near the margin of continental ice sheets such as that now covering Antarctica and formerly covering portions of all continents during past glacial ages. They can be as lo ...

s. Around the '' Zungenbecken'' on the edge of the former ice sheet, are ridges of

glacial till image:Geschiebemergel.JPG, Closeup of glacial till. Note that the larger grains (pebbles and gravel) in the till are completely surrounded by the matrix of finer material (silt and sand), and this characteristic, known as ''matrix support'', is d ...

known as

s. Till is the material that makes up ground, lateral and (not always present)

medial moraine A moraine is any accumulation of unconsolidated debris (regolith and rock), sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a glacier or ice shee ...

s. Ground moraine consists of material that was once beneath the glacier and was transported by it and deposited across wide areas of the former glacier bed. The

lateral moraine A moraine is any accumulation of unconsolidated debris (regolith and rock), sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a glacier or ice shee ...

s comprise that eroded material which is carried along at the sides of a glacier. A lateral moraine that is no longer being actively added to with glacial material because the glacier has retreated for climatic reasons, is known as a

flank moraine Flank may refer to: * Flank (anatomy), part of the abdomen ** Flank steak, a cut of beef ** Part of the external anatomy of a horse * Flank speed, a nautical term * Flank opening, a chess opening * A term in Australian rules football * The si ...

. In the Alps the remaining flank moraines were usually formed during the

Little Ice Age The Little Ice Age (LIA) was a period of regional cooling, particularly pronounced in the North Atlantic region. It was not a true ice age of global extent. The term was introduced into scientific literature by François E. Matthes in 1939. Ma ...

medieval In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the Post-classical, post-classical period of World history (field), global history. It began with t ...

times. They lie several metres higher than the present glacier surface and extend far beyond the present glacier snouts. Medial moraines are formed when the lateral moraines of two glaciers are combined when they flow together. On the far side of the morainic zone is the gravel

outwash plain An outwash plain, also called a sandur (plural: ''sandurs''), sandr or sandar, is a plain formed of glaciofluvial deposits due to meltwater outwash at the terminus of a glacier. As it flows, the glacier grinds the underlying rock surface and ca ...

, which was piled up by the meltwaters of the ice mass. Those waters usually came from

glacier cave A glacier cave is a cave formed within the ice of a glacier. Glacier caves are often called ice caves, but the latter term is properly used to describe bedrock caves that contain year-round ice. Overview Most glacier caves are started by wate ...

s whose former location is still recognisable today from the dips in the level of the terminal moraines. Often the gravel plains are markedly terraced; younger outlets have cut so-called little trumpet-shaped valleys in the older gravel plains. The material of the outwash plans is glacial till. The transport capacity of the meltwater is considerably less than that of the glacier, so that larger rocks cannot be carried out of the ''Zungenbecken''. By contrast, elements with smaller

grain size Grain size (or particle size) is the diameter of individual grains of sediment, or the lithified particles in clastic rocks. The term may also be applied to other granular materials. This is different from the crystallite size, which refer ...

, like

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...

s and

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of s ...

s can be transported much further, which is why they are rarely found in the gravel plains. Glacial meltwater valleys or ''Urstromtäler'' emerged as a result of meltwater flowing away in a direction parallel to the edge of the ice mass and are a feature of Northern Central Europe. These valleys, created by glacial meltwaters, do not appear in the Alpine Foreland as they do, for example, in North Germany because their function was assumed by the great rivers that already existed in the region - the

Danube The Danube ( ; ) is a river that was once a long-standing frontier of the Roman Empire and today connects 10 European countries, running through their territories or being a border. Originating in Germany, the Danube flows southeast for , pa ...

Rhine ), Surselva, Graubünden, Switzerland , source1_coordinates= , source1_elevation = , source2 = Rein Posteriur/Hinterrhein , source2_location = Paradies Glacier, Graubünden, Switzerland , source2_coordinates= , so ...

Rhône The Rhône ( , ; wae, Rotten ; frp, Rôno ; oc, Ròse ) is a major river in France and Switzerland, rising in the Alps and flowing west and south through Lake Geneva and southeastern France before discharging into the Mediterranean Sea. At Ar ...

and Po - or their tributaries, which transported away the meltwaters of the glaciers.

Glacial series in Northern Central Europe

The Scandinavian

ice sheet In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are in Antarctica and Greenland; during the Last Glacial Period at Las ...

reached or crossed Northern Central Europe several times. The landforms of the glacial series here thus follow one another from north to south: The ground moraine landscape consists predominantly in flat to gently rolling terrain, on which the ice mass deposited till. ''Zungenbecken'', where the scouring of material played a significant role, occur to a lesser extent and are an element of the ground moraine landscape in the Scandinavian glaciation region. Because the advancing ice sheet completely buried the landscape, ice age landforms and depositions are found over much of North Germany. Tunnel valleys, by contrast, are not commonly found in Northern Central Europe. Terminal moraines sweep in a giant arc around the ground moraine zone to the south. These terminal moraines are often incompletely formed and lower than in the Alpine Foreland, but are nevertheless clearly visible in the low-relief of the

North German Plain The North German Plain or Northern Lowland (german: Norddeutsches Tiefland) is one of the major geographical regions of Germany. It is the German part of the North European Plain. The region is bounded by the coasts of the North Sea and the Balti ...

. Because of their many gaps, the neutral term, ''Eisrandlage'' ("ice margin location") has been preferred for the line of terminal moraine ridges in North Germany. More or less extensive sandurs border the terminal moraines. They are

alluvial fan An alluvial fan is an accumulation of sediments that fans outwards from a concentrated source of sediments, such as a narrow canyon emerging from an escarpment. They are characteristic of mountainous terrain in arid to semiarid climates, but a ...

s created by the glacial meltwaters. They were also fed with water that poured out of the glacier caves and cut through the terminal moraine ridges. The meltwaters that flowed across the sandur, collected in the meltwater valley and flowed parallel to the margin of the ice sheet, mostly in a northwesterly direction. Meltwater valleys are a special landform in Northern Central Europe.

Glacial series as a model of landscape formation

Like all models, the model of the glacial series gives only a simplified picture of the real situation. In particular, it is often forgotten that the landforms of the glacial series were formed almost at the same time alongside one another, whilst the ice margin remained static by the terminal moraine. Furthermore the ice then had to advance as far as the later terminal moraines and then melt away again. The processes that accompany that, clearly alter the model of the glacial series. A common variation, for example, is the spillage of younger meltwaters over older ground moraine beds. In addition, a further advance of the glacier can result in the interlacing of various older landforms of the glacial series. For example, lines of terminal moraines lying close behind one another in the Brandenburg region of Germany drained over the same sandurs and via the same meltwater valley.

Literature

* J. Ehlers: ''Allgemeine und historische Quartärgeologie'', 358 S., Stuttgart 1994, * A. Penck: ''Die Vergletscherung der deutschen Alpen'', Leipzig 1882 * ''Führer zur Geologie von Berlin und Brandenburg, Nr. 9, Oderbruch - Märkische Schweiz - Östlicher Barnim'', Johannes H. Schroeder (ed.), Geowissenschaftler in Berlin und Brandenburg e.V., Selbstverlag Berlin, 2003, , ISSN 0941-2980

References

External links

''Kleines Glossar zur Glazialmorphologie'', Zentrale für Unterrichtsmedien im Internet e.V.

''Infoblatt Glaziale Serie'', Klett Verlag

''Infoblatt Gletscher'', Klett Verlag

''Karte von Europa: Letzte Eiszeit - Landschaft während der Weichsel- und Würmeiszeit'', Klett Verlag

''Gletscher und Eisschilde'', Vorlesung ''Geophysik der Erde'' at Vienna University of Technology
{Dead link, date=December 2019 , bot=InternetArchiveBot , fix-attempted=yes (pdf file; 6.01 MB) Series Ice ages Pleistocene Europe