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The Duffelt as it is nowadays The Duffelt Our family comes from the Duffelt, the Dutch/German polder region, which is bordered on the north side by the river Rhine/Waal and the on the south side by a range of hills, which stretches from Nijmegen to Kleef ( Kleve in German, English Cleve), the two cities which, as it were, fence off the region. To day the frontier between Germany and the Netherlands cuts it right across. The landscape of the Lower Rhine (Waal), in which the Duffelt is situated, is one of the most varied landscapes of Western Europe. A spacious and beautiful area, where the Rhine majestically meanders to the West, covered by splendid cloudy skies and, at large distance, the silhouettes of the “Swan-castle” of Kleve, the cathedral of Xanten, the St.Vitus-church of High Elten, the Waal bridge and the skyline of Nijmegen. The landscape is built up by several terraces; the river-bed of the Rhine and the grasslands in the forelands, the fields and the fat clay grounds behind the dikes where you can still see the marks of former river branches and dike-bursts, and the foot of the moraine-walls driven up in the last glacial period and overgrown with deciduous tree, and the upland plains, originally wooded, then cleared, down-graded to moorland and cleared again today. Millions of years ago this area was a shallow lagoon ( the same held good with the rest of the Netherlands; the coastal line was at the time about the line Gene-Kleve.) In the last period but one, abt.200.000 ago, so much snow came down that the enormous thick ice-cap formed on the Scandinavian Highland (cf. The ice-cap of Greenland today). This cap began to expand to all sides and crossed- as a glacier- the Baltic Sea and Northern Germany to the Low Countries. During the last ice-age, about 50.000 years ago, a wild streaming river system with alpine glaciers and mid-European meltwater changed the Duffelt into a large gravel-sand river plain. Just before the end of the ice age- about 12.000 years ago- these water streams withdrew into the Betuwe and carved in the underground a valley (about 5 meters deep); there are indications, that this valley reached as far as the northern Duffelt. But south of the line Rinderen-Niel-Persingen the sand-gravel plain of the ice-age (the lower terrace) was not affected anyway; the river branches withdrew from this plain, though they have left behind enormous layers of clay during the last few inundations.
Gradually the Rhine filled its erosion valley of the Betuwe and the Northern Duffelt up with clayish sand and clay. Only 4000 years ago this filling material reached the level of the lower terrace. Because of this the Rhine could for the first time since 8000 years inundate again the Southern Duffelt and the sediments of young clay got started. That is why the sediment of clay in the Southern Duffelt is less substantial than in the northern part of this polder area. As we have seen, the greater part of the Duffelt consists of young river-clay. But there are great differences in proportion to the spot. During inundation’s particles of sand and clay are suspended in the river water. According as the water gets farther away from the river itself the speed of the current ergo the speed of transport decreases. First the sand sinks, so close to the river; the clay father away. In between are mixtures and in some places there is no clay at all in the water and there peat swamps come into being. When the flooded areas dry up the clay sets, but the sandy-clay to a less extent and in this way relatively higher river banks come into being; (“ current sand ridges”) In the late Iron-age and in the Roman age the river-clay areas and the higher ridges were already rather densely inhabited and agriculture expanded.
About 250 AD the Rhine began to behave very wildly because of changed climatic circumstances; many inundations and diversions took place and great parts of the ridges were washed away and sank to great depths and in this way traces of former inhabitation were wiped out. People left the region but returned in the Merovingian, but mainly in the Carolingian time (800 AD.) The later ridges are less high: Millingen, Kekerdom, Erlecom, Tiengeboden, Nijmegen. During the Middle Ages people started to settle down on these ridges not far from Beek. Lake Wijler. The inundation of the lower terrace between Mehr and Wijler were so immense that the floodwater between the Wijler highgrounds and the drift-sand ridge of Zyfflich was dammed up in a funnel-shaped depression until it broke through the drift-sand ridge. The strong current worn out a long channel against the hillside, Lake Wijler! From the 8th century on the inhabitants began to protect themselves against the water by placing ring-dikes round the settlements. However this was not always of avail. The ridge Rinderen-Millingen, for exemple, was often overflown by high water. After the Roman period a one-meter thick clayish deposit grew on the top of it. It is as high as 12½ meter + NAP. (New Amsterdam Peil = sea-level) and that is on the spot 1 meter above the level of the forelands. This kind of disasters eventually led to the building of robust dikes. The first one: Kleve-Millingen-Kekerdom-Wijler was finished about 1300 AD. Shortly after that Wercheren-Ooy (Kerkendijk)-Tiengeboden-Nijmegen followed. Up to now only the bank-grounds had been broken up, but now the inhabitants could start to disforest and clear the alder brakes in the lower grounds which had frequently been inundated in the past. The diking in interrupted the natural development of the Duffelt, but by the endiking, ergo the narrowing of the river, the water level became higher than before and dikebursts occurred manifold and produced whirlpools and fan-shaped sandbanks. In the lower areas only a few country folks had settled down since the middle ages and had leveled up their hamlets to mounds. Several old farmhouses in the Duffelt are still situated on such mounds. Since the last inundations of 1918 and 1926 man seems to have a thorough command of the situation, though in January 1995 it was “ close shave” again. Because of the brickproduction many large clayholes appear along the river. The clay of the lower parts is unsuitable for brickproduction, but the sandy ridge clay is. Especially the clay of the young ridges. ( Tiengeboden, Ooij and Kekerdom).
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