North European Plain Research Articles

Palaeozoic amalgamation of Central Europe: new results from recent geological and geophysical investigations

Multidisciplinary studies of geotransects across the North European Plain and Southern North Sea, and geological reexamination of the Variscides of the North Bohemian Massif, permit a new 3-D reassessment of the relationships between the principal crustal blocks abutting Baltica along the Trans-European Suture Zone (TESZ). Accretion was in three stages: Cambrian accretion of the Bruno–Silesian, Lysogory and Malopolska terranes; end-Ordovician/early Silurian accretion of Avalonia; and early Carboniferous accretion of the Armorican Terrane Assemblage (ATA). Palaeozoic plume-influenced metabasite geochemistry in the Bohemian Massif explains the progressive rifting away of peri-Gondwanan crustal blocks before their accretion to Baltica. Geophysical data, faunal and provenance information from boreholes, and dated small inliers and cores confirm that Avalonian crust extends beyond the Anglo-Brabant Deformation Belt eastwards to northwest Poland. The location and dip of reflectors along the TESZ and beneath the North European Plain suggest that Avalonian crust overrode the Baltica passive margin, marked by a high-velocity lower crustal layer, on shallowly southwest-dipping thrust planes forming the Heligoland–Pomerania Deformation Belt. The “Variscan orocline” of southwest Poland masks two junctions between the Armorican Terrane Assemblage (ATA) and previously accreted crustal blocks. To the east is a dextrally transpressive contact with the Bruno–Silesian and Malopolska blocks, accreted in the Cambrian, while to the north is a thrust contact with easternmost Avalonia, deeply buried beneath younger sedimentary cover. In the northeast Bohemian and Rhenohercynian Massifs Devonian “early Variscide” deformation dominated by WNW and NW-directed thrusting, records closure of Ordovician–Devonian seaways between detached “islands” of the ATA and Avalonia.

Plant communities and plant diversity in softwater lakes of northern Europe

Numbered in hundreds of thousands, and ranging from <1 ha in area to Europe’s largest lake (Lake Ladoga), North European softwater lakes (lime-deficient waterbodies, ranging from low-nutrient, low pH to meso-eutrophic, circumneutral pH) support an important plant component of the biodiversity resources of Europe. Within this region (comprising the British Isles, Scandinavia, and the North European Plain from Brittany to the Baltic States), some 24 softwater lake euhydrophyte community types occur, including stress-tolerant isoetid communities which particularly characterise softwater lake vegetation. A number of rare species are supported, including plants, such as Eriocaulon aquaticum, which are found nowhere else in Europe. In line with the predictions of the hump-back model of diversity–productivity relationships in lakes, the individual plant diversity found in softwater lakes in this region is low (six or fewer euhydrophyte species present, e.g. in acidic, ultraoligotrophic lakes) to moderately high (>20 euhydrophyte species in lakes with, for example, mesotrophic conditions with pH <7.0). Overall, however, a large set of plant species (>100) occurs, forming assemblages which play a vital role in the functioning of softwater lake ecosystems. Lake area, altitude, trophic state and water quality have been found to be good predictors of macrophyte species richness for lakes within this area. Major threats to the survival of softwater lake vegetation include acidification, eutrophication, increased recreational use of lakes, and the effects of lake regulation for hydro-electric schemes. All such pressures tend to reduce the diversity of typical softwater species present in affected lakes. In addition, there is increasing concern about the possible impacts of global CO 2 increase for the continued survival of (especially) isoetid vegetation which is strongly adapted to ambient conditions of limited dissolved inorganic carbon availability in softwater lakes. The implications of such global change for the maintenance of softwater lake plant diversity in northern Europe are potentially severe.

Climate Change and the Adoption of Agriculture in North-West Europe

Farming can be shown to have spread very rapidly across the British Isles and southern Scandinavia around 6000 years ago, following a long period of stasis when the agricultural ‘frontier’ lay further south on the North European Plain between northern France and northern Poland. The reasons for the delay in the adoption of agriculture on the north-west fringe of Europe have been debated by archaeologists for decades. Here, we present fresh evidence that this renewed phase of agricultural expansion was triggered by a significant change in climate. This finding may also have implications for understanding the timing of the expansion of farming into some upland areas of southern and mid-latitude Europe.

Climate change and the adoption of agriculture in north-west Europe

Farming can be shown to have spread very rapidly across the British Isles and southern Scandinavia around 6000 years ago, following a long period of stasis when the agricultural ‘frontier’ lay further south on the North European Plain between northern France and northern Poland. The reasons for the delay in the adoption of agriculture on the north-west fringe of Europe have been debated by archaeologists for decades. Here, we present fresh evidence that this renewed phase of agricultural expansion was triggered by a significant change in climate. This finding may also have implications for understanding the timing of the expansion of farming into some upland areas of southern and mid-latitude Europe.

Finland's Settling Model Revisited

The author examines the competing hypotheses that have been advanced to explain the origin and migration routes of the Finns, including the suggestion that they formerly inhabited parts of the North European plain immediately to the south of Scandinavia during the latter part of the Wurm glaciation. As the ice retreated northwards at the end of the Fourth or Wurm glaciation, the ancestors of the Finns similarly moved into Finland from a more easterly part of the North European plain, along the eastern rim of the expanding lake which later became the Baltic Sea. Key Words: Finns, Saami, Finno-Ugric languages, Indo-European languages, Upper Paleolithic, Mesolithic, Scandinavia, Baltic Sea, North European archeology, Wurm glaciation. In 1980, 1 included a model for the spread of Mesolithic hunters into deglaciating northern Europe at the end of the Ice Age as a chapter of my PhD thesis. A slightly modified version was later published in an article, A model for the early settlement of Finland (1987). The latter was intended as a provocation to prompt discussion, and that it did (Dolukhanov 1989; Leskinen 1989; Welinder 1989; Nunez 1989); though perhaps not enough. Subsequently, I have updated the subject in lectures and papers on various occasions (e.g. Nunez 1990, 1995; Nunez and Taavitsainen 1992). The present article is, as the heading suggests, a reassessment of this 17 year-old model in the light of old and new information. On the Dates Used There is no longer an excuse not to use calibrated radiocarbon dates in Finnish archeology now that the tree-ring calibration curve extends far back enough to encompass the whole of Finnish prehistory. This work uses tree-ring calibration for conventional radiocarbon dates back to 10,000 bp (ca. 9200 cal BC) and the calibration based inferred atmospheric spline of coral data for conventional dates within 10,000-18,800 bp (ca. 9200-22,000 cal BC). Since this may be confusing to researchers used to other dating systems, the calibrated values for dates between 7500 and 22,000 cal BC will be followed by the corresponding conventional dates labeled bp. To avoid an overlap between calibrated dates and those that fall outside the calibration range, conventional dates beyond 18,800 bp will be adjusted by adding 3,000 years and labelled BC. Thus 22,000 bp will become 23,000 BC. The 3,000 years roughly corresponds to the difference between the last calibratable conventional date and its calibrated value: 18,899 bp and 21,950 cal BC. All calibrated dates used here have been obtained with Stuiver's and Raimer's (1993) program. As was the case in the original model (Nunez 1987), the central calibrated values have been rounded off to the nearest 100 years. The Original Model The original model is rather general, both because when it was created - and even now - our knowledge of the vast territories involved was very patchy and because simple general models are best suited to explain long-term processes over large areas. Like T.H. White's hawk, I tried to look at late glacial Europe from such a height that details became blurred and the general underlying processes discernible. The model was based mainly on the extant paleoenvironmental and archeological data and assumed the following: 1. During the glacial maximum, ca. 23,000 BC - 19,500 cal BC (ca. 22,000-18,000 bp) human groups had successfully adapted to life in the inhabitable zone in the periphery of the ice sheet - the so-called marginal zone. 2. It took at least four millennia for the ice border to retreat from its maximum position across northern Europe to southern Finland. 3. The territories uncovered by the gradually receding ice sheet logically would have become occupied by those human groups living in adjacent areas of the marginal zone. 4. These groups spread metachronically (time-transgressively) with the gradually retreating ice border, reaching southern Finland by 8000 cal BC (ca. …

The Eemian interglacial in the North European plain and adjacent areas

AbstractMany small deposits of Eemian age, including the stratotype, are found right across the North European plain. In adjacent areas, this interglacial is known by local names such as Ipswichian (Britain), Luhe or Ribains (France), Riss-Würm interglacial (Alps) and Mikulinian (Poland and Russia). It correlates primarily with MIS 5e of the deep-sea stratigraphy, though boundaries may not be exactly the same. Basins containing Eemian sediments rest directly on morainic deposits of all three Saalian ice advances, which must all, therefore, fall within MIS 6.Indicator species of both plants and animals suggest that mean July temperatures in the early-temperate part of the interglacial were warmer than during the Holocene. For many years, palynologists have recognised a very uniform succession of temperate tree acme pollen zones and a substantial late-temperate expansion ofCarpinusas hallmarks of this interglacial across much of northern Europe. In southern England, however, deposits with a similar pollen signature are being recognised on stratigraphie and palaeontological grounds as characterising not only the Ipswichian but also the previously poorly-defined interglacial stage correlating with MIS 7. HighCarpinusvalues are known from these latter sites and from the Le Bouchet inter-glacial of the French Massif Central, also clearly correlated with MIS 7. Thus stratigraphie confusion and misinterpretations may have occurred at supposedly Eemian/Ipswichian sites unrelated to the glacial stratigraphy or to deep continuous records.The uniformity and rapid development of Eemian vegetational successions may be ascribed to (1) rapid warming and the lack of any late-glacial climatic oscillation on the scale of the Younger Dryas, (2) the development of an open marine connection in the first half of the interglacial from the English Channel across the North and Baltic Seas to the White Sea and the Arctic Ocean, and (3) the occurrence of Saalian per-glacial refugia forCarpinus, not only in the Balkans but also on the Iberian peninsula, permitting much more rapid northward colonisation of Europe during this interglacial.The question of climatic events within the Eemian is far from settled. Not only is the ice-core evidence ambiguous and awaiting further clarification, but the scale and synchroneity of proposed events at different continental sites in both northern and southern Europe show no clear pattern at present; clearly there is a need for more detailed investigation and interpretation. Likewise there is ongoing debate about the duration of this interglacial and its detailed correlation with the deep-sea core record and events within the North Atlantic Ocean.

Chattian and Miocene elements in the modern landscape of western Britain and Ireland

Abstract The best preserved denudation surfaces which are benched into the margins of the pre-Permian oldland massifs of western Britain and Ireland are those comparatively close to sea-level. Such surfaces have frequently been regarded as being of late Pliocene or Pleistocene age and of marine origin. Recent discoveries reviewed in this work reinforce a growing view that these low-level planations are much older and may be of terrestrial origin. Evidence from Wales and southwest England suggests that these little-modified planation elements represent landscapes some 15 Ma old. This paper reviews the palaeobotanical, sedimentological and geomorphological evidence for the close association of several bodies of non-marine Chattian and Miocene sediment and saprolite with some of the better known planation features. In these areas, the former vegetation comprised mixed coniferous/deciduous forest, extinct species of modern north temperate genera, well known from contemporaneous deposits in north Europe. Evidently, differential relief in those times was appreciably less than that of the present and it seems probable that much of what is now the western half of the British Isles was then a wide, forested extension of a previous North European Plain, which varied in altitude by no more than a few decametres.

Humans at the End of the Ice Age: The Archaeology of the Pleistocene-Holocene Transition

Introduction: The World at the End of the Last Ice Age L.G. Straus. The Pleistocene-Holocene Transition in Africa and the Near East: L. Straus. At the Transition: The Archaeology of the Pleistocene-Holocene Boundary in Southern Africa P.J. Mitchell, et al. Plus Ca Change: The Pleistocene-Holocene Transition in Northeastern Africa A.E. Close. The Impact of Late Pleistocene-Early Holocene Climatic Changes on Humans in Southwestern Asia O. Bar-Yosef. The Pleistocene-Holocene Transition in Europe: B.V. Eriksen. The Archaeology of the Pleistocene-Holocene Transition in Southwest Europe L.G. Straus. Resource Exploitation, Subsistence Strategies and Adaptiveness in Late Pleistocene-Early Holocene Northwestern Europe B.V. Eriksen. The North European Plain and Eastern Sub-Balticum between 12,000 and 8,000 B.P. R. Schild. The Pleistocene-Holocene Transition on the East European Plain P.M. Dolukhanov. Asia and Australia during the Pleistocene-Holocene Transition: J.M. Erlandson. The Pleistocene-Holocene Transition in Greater Australia J. Allen, P. Kershaw. Human Activities and Environmental Changes during the Late Pleistocene to Middle Holocene in Southern Thailand and Southeast Asia S. Pookajorn. The Pleistocene-Holocene Transition in Japan and Adjacent Northeast Asia: Climatic and Biotic Change, Broadspectrum Diet, Pottery, and Sedentism C.M. Aikens, T. Akazawa. Siberia in the Late Glacial and Early Postglacial W.R. Powers. Environments and Peoples at the Pleistocene-Holocene Boundary in the Americas D.R. Yesner. Human Adaptation at the Pleistocene-Holocene Boundary (ca. 13,000 to 8,000 B.P.) in Eastern Beringia D.R. Yesner. The Pleistocene-Holocene Transition along the Pacific Coast of North America J.M. Erlandson, M.L. Moss. The Pleistocene-Holocene Transition on the Plains and Rocky Mountains of North America G.C. Frison, R. Bonnichsen. The Pleistocene-Holocene Transition in Eastern United States D.F. Morse, et al. The Pleistocene-Holocene Transition in Southern South America L.A. Borrero. Conclusion: Surprises, Recurring Themes, and New Questions in the Study of the Late Glacial and Early Postglacial M.A. Jochim. Index.

Evidence for possible use of plant foods in Palaeolithic and Mesolithic diet from the site of Całowanie in the central part of the Polish Plain

Calowanie site, which supported hunter-gatherer populations from ca. 11 380±95 until 8270±100 B.P., is the major terminal Palaeolithic and early Mesolithic occupation complex of the North European Plain. The archaeological layers are intercalated with biogenic sediments. The remains of plants that probably served as food were recovered from terminal Palaeolithic and early Mesolithic layers. Most of the charred plant remains, apart from wood charcoal, derives from vegetative parenchyma which forms a major part of organs such as root and tuber. Two taxa have been identified on the basis of the anatomy of parenchymatous tissue, namely Sagittaria cf. sagittifolia and Polygonum sp. In addition, several charred seeds and fruits were recovered. This is the first evidence for the probable use of plant foods, other than hazel nuts or water-chestnuts, in the diet of hunter-gatherers in the North European Plain during the Palaeolithic and Mesolithic.

Problems of dead ice and ground ice in the central part of the North European Plain

Five sections of sediment from mire infillings located in different part of the catchment small river valley in central Europe were studied by lithological and geochemical analysis in order to examine the response of aquatic ecosystems to the environment changes during Late Weischselian (LW). Differentiation of geochemical composition and grain-size properties in biogenic deposits is being considered as a result of change hydroclimatic conditions and geology structure in individual parts of the catchment. The principal component analysis (PCA) and clustered by hierarchical method (HCA) were chosen to create the lithogeochemical facies and their chronostratigraphy variability. Biogenic sediments of the studied river mires, regardless of the location in a given reach of the valley, are represents mainly by mineral or organic-mineral lithogeochemial facies with increased of lithophilic elements (Na, K and Mg). Similar chemical composition of gyttja and peat sediments in almost all periods of LW, indicate the strongly mechanical denudation processes in the Grabia River valley. The major process, conditioning the development of the mires (in it type and rate sedimentation), was the variable terrigenous material input which are related to its variable dynamic of floods. The higher than expected chemical denudation probably a result of specific groundwater flow direction and dissolving vari-grained sands and silts, which build plains in the central part of the study catchment. The number and thickness of individual lithogeochemical facies are caused by differences in the potential volume of the hydrologically active zone and geological conditions of the emerge or disappear permafrost.

TRB Culture: The First Farmers of the North European Plain.

Geographical background the late hunter-gatherers of the North European plain and the neighbouring central European farmers the late Mesolithic groups the early farming groups the TRB culture - the historical background regional ceramic sequences of the TRB culture the absolute chronology of the TRB culture stone, flint and other industries of the TRB culture the settlement patterns of the TRB culture the economy of the TRB culture funerary traditions in the TRB culture non-Megalithic grave forms of the TRB the social dimensions of the TRB conclusions TRB culture radiocarbon dates.

The Pavlov Site, Czech Republic: Lithic Evidence from the Upper Paleolithic

AbstractA research project aimed at thorough description of the large Upper Paleolithic (Pavlovian) site clusters around Pavlov and Dolni Věstonice, southern Moravia, Czech Republic, has analyzed the lithic industry of Pavlov I (excavated in 1952). The raw materials were imported from distances of about 100 km (radiolarite) and more than 120 km (various “flints“);, the radiolarite, the scarcer of the two, seems to have been processed more economically than the flints. Closer outcrops of various Moravian cherts, intensively utilized by other groups, apparently were avoided by the Pavlovians. Long-distance acquisition of raw material suggests mobility along the axis between the North European Plain, through the narrow Moravian Gate, and the Danube valley.It seems probable that the duration of the various occupations at sites like Pavlov I or Dolni Věstonice I was longer than at Pavlov II or Dolni Věstonice II. The Pavlovian sites are no longer regarded as large “villages” however.,but rather as horizontal c...

Trb Culture: The First Farmers of the North European Plain. By MagdalenaS. Midgley

(1993). Trb Culture: The First Farmers of the North European Plain. By Magdalena S. Midgley. Archaeological Journal: Vol. 150, No. 1, pp. 519-520.

Paysages Agraires, Couverts Vegetaux, et Processus D'Erosion en Milieu Tempere de Planine de l'Europe de L'Ouest

Summary The author has focussed his study on temperate environments of plains and hills, a particularly neglected geographic field. Nevertheless it is in the heart of the present day environmental and management problems. This site situated in the Centre of Middle Europe is not only a sector of the north european plain but is also laying between the parisian metropolis and the rhenan axis, southwards of Benelux which seems a vital centre under influences. These questions have been considered for a long time. A field equipment (erosion plots) has been installed on a watershed in the north of Parisian basin; it gives a lot of data since 12 years and more over it permits the testing of new recording instruments. The will is to extend this field of research by considering both natural data and anthropic actions studied in particular through agrarian landscapes and canopies. Concerning the spatial point of view the scale of the survey has been enlarged from the erosion plot up to the catchment area. This proves how much the author's scientific investigations are incontestably implied in topical question of lands erosion in the whole of Europe, for preserving its soil amount. To every scale level it corresponds a coherent set of technologies and methodologies: some significant advancements are also proposed.

The Eccentricity of Wheels, or Eurasian Transportation in Historical Perspective

EVEN IN THIS AGE OF AIR TRAVEL, WHEN WE THINK OF TRANSPORTATION, we think first of wheeled vehicles trucks, trains, or cars and then of ships that sail across open water. This vision of how goods and people travel is accurate enough when applied to most of the European past, and Europeans were able to impose their style of transportation, and much else, on the rest of the world in the course of the past century and a half. But a broader historical perspective makes the familiar European definition of transport misleading because it omits animal portage-the caravan-and overlooks the sporadic importance of canals. This essay will attempt to redress the balance by putting the peculiarities of European transport systems into their appropriate world historical framework. Edward Fox, in his History in Geographic Perspective: Other France, emphasized the difference between movement by water and movement by land. ' He pointed out that, before the railroad changed traditional patterns, water transport was both much cheaper and much more capacious than overland haulage. As a result, according to Fox, two diverse societies arose within France: one outward-looking, comnmercial, and maritime; the other rural, politically subject, and intensely local in economic matters. Links between the two were mainly political and quite slender: hence his subtitle, The Other France. Fox may have exaggerated the separateness of rural from urban France, but his emphasis on the defects of European overland transport in the pre-industrial age is surely well taken. Before the second half of the eighteenth century, when the French pioneered systematic road building, European roads were little more than a succession of mud holes. During much of the year, the moist climate made roads all but impassable for wheeled vehicles, especially wagons carrying heavy goods. In contrast, abundant precipitation combined with the almost flat topography of the north European plain to provide Europeans with a natural substitute for roads-the river system, which, with remarkably little artifical improvement, allowed easy movement far inland, thanks to comparatively placid currents and a fairly even flow of water throughout the year. Indeed, Europeans could put up with backward and inefficient overland transport before the eighteenth century only because the natural system of internal waterways was so good. Why bother

The Eccentricity of Wheels, or Eurasian Transportation in Historical Perspective

EVEN IN THIS AGE OF AIR TRAVEL, WHEN WE THINK OF TRANSPORTATION, we think first of wheeled vehicles trucks, trains, or cars and then of ships that sail across open water. This vision of how goods and people travel is accurate enough when applied to most of the European past, and Europeans were able to impose their style of transportation, and much else, on the rest of the world in the course of the past century and a half. But a broader historical perspective makes the familiar European definition of transport misleading because it omits animal portage-the caravan-and overlooks the sporadic importance of canals. This essay will attempt to redress the balance by putting the peculiarities of European transport systems into their appropriate world historical framework. Edward Fox, in his History in Geographic Perspective: The Other France, emphasized the difference between movement by water and movement by land. ' He pointed out that, before the railroad changed traditional patterns, water transport was both much cheaper and much more capacious than overland haulage. As a result, according to Fox, two diverse societies arose within France: one outward-looking, comnmercial, and maritime; the other rural, politically subject, and intensely local in economic matters. Links between the two were mainly political and quite slender: hence his subtitle, "The Other France." Fox may have exaggerated the separateness of rural from urban France, but his emphasis on the defects of European overland transport in the pre-industrial age is surely well taken. Before the second half of the eighteenth century, when the French pioneered systematic road building, European roads were little more than a succession of mud holes. During much of the year, the moist climate made roads all but impassable for wheeled vehicles, especially wagons carrying heavy goods. In contrast, abundant precipitation combined with the almost flat topography of the north European plain to provide Europeans with a natural substitute for roads-the river system, which, with remarkably little artifical improvement, allowed easy movement far inland, thanks to comparatively placid currents and a fairly even flow of water throughout the year. Indeed, Europeans could put up with backward and inefficient overland transport before the eighteenth century only because the natural system of internal waterways was so good. Why bother

The Establishment of Agrarian Communities on the North European Plain [and Comments and Reply

L'introduction de l'economie de production dans les plaines d'Europe septentrionale a ete un processus complexe. Il convient de distinguer les communautes agraires exogenes qui ont penetre dans les basses-terres et les communautes indigenes, de substrat mesolithique, qui ont finalement adopte l'agriculture. La nature de ces deux populations et des modeles de leurs interactions sont discutes

Tree-ring and varve scales combined, c. 13500 B.C. to A.D. 1977

Varve chronologies are of several kinds but glacial varves respond to summer temperature and fluvial varves to summer rainfall. Tree-ring chronologies near the timberline respond to summer temperature but European oak chronologies respond to summer rainfall. Certain global features of the weather of the summer season, notably the Biennial Index, are therefore parameters that can be used for cross-dating both varves and tree-rings in different continents. Characteristic curves for different parameters in the Late Glacial (Zones Ia, Ib and II) and in the past thousand years are presented. A moisture curve is given for the North European Plain (200 B.C.–A.D. 1100). A conversion chart for tree-rings and radiocarbon dates is extended back into the Late Glacial on the tentative assumption that the radiocarbon error was about 950 years at the beginning of the Holocene (III/IV), i.e. that 10300 b.p. should be 11250 B.P. or 9300 B.C. Supplementary sources of information useful in obtaining approximate dates include: (a) palaeomagnetism; (b) tephrochronology and X-ray analysis; (c) cycle analysis; (d) climatic peculiarities associated with specific radiocarbon centuries; (e) X-ray analysis of specific varves; and (f) new methods of varve-analysis. The varve-series used for the Late Glacial, if the author's cross-dating between North America and Scandinavia is acceptable, constitute a floating chronology of about 4000 years. Given approximate 14C dates for any long series of varves or tree-rings in one part of the world, it is now possible to obtain cross-dating with any other long series in another part of the world, and it will be easy to replace the tentative ‘950-year’ error by a precise figure determined from a combined varve and tree-ring scale extending back from the present day to (say) the zero of Sauramo's scale for varves in Finland. In the meantime the ‘950’ is mnemonically convenient, as this would make the year on the B.C. scale one thousand less than the year on the b.p. scale.

Distribution of loess in Britain

The distribution of recorded British loess deposits is reviewed and a threefold division, taking age and type of deposit into account, is suggested based on extensive field observations and literature interpretation. The loess is divided into the interglacial deposits, the postglacial silty drift deposits and the brick-earth deposits of south-east England. A Hobbsean anticyclone can provide the conditions for the deposition of loess in south-east England. A glacial anticylcone over Scandinavia would give rise to an easterly air flow across the North European Plain from western Russia to northern France and south-east England. This mechanism allows the deposits in south-east England to be considered to be part of the northern band of European glacial loess.

The Distribution and Migrations ofLocustain Europe

1. From the study of the historical records of European invasions byLocustafrom the 14th century to the present day, it is concluded that the subspecies concerned wasL. m. migratoriaoriginating in the West Pontian outbreak area. This area formerly comprised the lower courses of rivers draining into the Black Sea from the Danube to the Dniepr inclusive, and is now confined to the delta of the Danube. From here swarms migrated into central Europe and the eastern part of the north European plain. The northern part of the plain, the British Isles and Fenno-Scandia, lie on the outskirts of the invasion area, and as a rule were only reached by small detachments from swarms. The decline of the West Pontian outbreak centres was accompanied by the gradual decline of the area subject to invasions by large swarms, but during outbreaks small groups and separate individuals of ph.gregariacontinue to reach the further limits of the invasion area.2. The distances covered within a single generation by swarms ofL. m. migratoriain temperate Europe (up to 1,600 miles) were comparable in extent to those traversed byL. m. migratorioidesin tropical Africa.3. Long-range migrations to the extreme limits of the invasion area are not confined toL. m. migratoriaph.gregariabut occur also in ph.solitaria. This is shown by the arrival of individuals of this phase in the British Isles during theperiod when the West Pontian outbreak areas are in a quiescent state. From this and from literature data on other locust species it is concluded that long-range migration is a regular seasonal phenomenon in swarming acrididae, independent of the presence of large numbers or the phase.4. The late summer immigration ofL. m. migratoriainto the British Isles may be a part of a more general east to west movement of flying insects which may occur in Europe at that season.5. It is probable thatL. m. migratoriasometimes oviposit in the British Isles, for they may arrive in a mature state, or during exceptionally hot summers in southeastern England they may reach sexual maturity after arrival. The eggs, however, are apparently unable to survive winter conditions.