The Elfas is a range of hills up to in the districts of

Holzminden Holzminden (; ) is a town in southern Lower Saxony, Germany. It is the capital of the district of Holzminden (district), Holzminden. It is located on the river Weser, which at this point forms the border with the state of North Rhine-Westphalia. ...

and

Northeim Northeim (; ) is a town in Lower Saxony, Germany, seat of the Northeim (district), district of Northeim, with a population of 30,118 as of 31 December 2023. It lies on the German Half-Timbered House Road. History Northeim is first mentioned in ...

Lower Saxony Lower Saxony is a States of Germany, German state (') in Northern Germany, northwestern Germany. It is the second-largest state by land area, with , and fourth-largest in population (8 million in 2021) among the 16 ' of the Germany, Federal Re ...

(

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

). Its name is derived from the Lower Saxon word ''Fast'', which means an area of upland that descends on two sides.

Geographical location

The Elfas is located in the middle of the

Leine Uplands The Leine Uplands (, ) is a region in Germany's Central Uplands which forms a part of the Lower Saxon Hills and lies along the River Leine between Göttingen and Hanover. It borders on the Weser Uplands in the west, the Innerste Uplands in th ...

between the

Hils The Hils is a range of hills in Germany's Central Uplands that is up to 480.4 m high. It is located in the districts of Landkreis Holzminden, Holzminden, Landkreis Hildesheim, Hildesheim and Landkreis Northeim, Northeim, in the state of Lowe ...

to the north, the Homburg Forest to the west, the Hube to the east, the

Amtsberge The Amtsberge are a small ridge of hills, up to ,''Wandern und Freizeit im Naturpark Solling-Vogler'', topographische Karte (1:50.000; 1975),Herausgeber, Hrsg.: Niedersächsisches Landesverwaltungsamt – Landesvermessung near Dassel in so ...

to the south-southwest and the

Holzberg The Holzberg is a small range of hills up to in south Lower Saxony, Germany. Geography The forested ridge of the Holzberg is located in the district of Landkreis Holzminden, Holzminden at the junction of the Leine Uplands in the east and the Wes ...

to the southwest. It lies not far southwest of

Eschershausen Eschershausen () is a municipality in the Holzminden (district), district of Holzminden, in Lower Saxony, Germany. It is situated approximately 20 km northeast of Holzminden, and 50 km south of Hanover. Eschershausen was the seat of the ...

and east of

Stadtoldendorf Stadtoldendorf is a town in the center of the Holzminden district, Lower Saxony, Germany. Stadtoldendorf is the seat of the ''Samtgemeinde A (, ; plural: ''Samtgemeinden'') is a type of administrative division in Lower Saxony, Germany. ''Sam ...

; the town of

Einbeck Einbeck (; Eastphalian: ''Aimbeck'') is a town in the district Northeim, in southern Lower Saxony, Germany, on the German Timber-Frame Road. History Prehistory The area of the current city of Einbeck is inhabited since prehistoric times. Vario ...

is about 12 km southeast of the Elfas. The B 64 federal highway runs past the Elfas to the north linking Eschershausen with Einbeck. The rounded summits of the Elfas are covered by

acidic soil Soil pH is a measure of the acidity or basicity (alkalinity) of a soil. Soil pH is a key characteristic that can be used to make informative analysis both qualitative and quantitatively regarding soil characteristics. pH is defined as the nega ...

beech forests.

Geology

The Elfas is mainly composed of

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

s from the

Bunter sandstone The Buntsandstein (German for ''coloured'' or ''colourful sandstone'') or Bunter sandstone is a lithostratigraphic and allostratigraphic unit (a sequence of rock strata) in the subsurface of large parts of west and central Europe. The Buntsands ...

period. As the result of a halokinetic process, which had already been concluded in the

Palaeogene The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...

period, the Elfas

fault block Fault blocks are very large blocks of rock, sometimes hundreds of kilometres in extent, created by Tectonics, tectonic and localized stresses in Crust (geology), Earth's crust. Large areas of bedrock are broken up into blocks by Fault (geology) ...

migrated in a north-easterly direction towards the

Solling The Solling () is a range of hills up to high in the Weser Uplands in the German state of Lower Saxony, whose extreme southerly foothills extend into Hesse and North Rhine-Westphalia. Inside Lower Saxony it is the second largest range of hill ...

, whereby the mountain-building sandstone rode up over a layer of saliniferous rock of the

Zechstein The Zechstein ( German either from ''mine stone'' or ''tough stone'') is a unit of sedimentary rock layers of Late Permian ( Lopingian) age located in the European Permian Basin which stretches from the east coast of England to northern Poland. T ...

. In the course of this process, mainly older rock strata that had hitherto lain underneath, were overthrust. Out of the subsequent erosion processes today's scarpland emerged as the northern boundary of the Einbeck-Markoldendorf Basin. Geologists in the Weser Uplands also use the terms Elfas Axis (''Elfas-Achse'') or Elfas Fault (''Elfas-Überschiebung'') for the regional fault line, as well as the term ''Elfas Saddle''.

Hills

The hills in the Elfas include (heights in metres above NN): * Helleberg (409.6 m) * Ahrensberg (405 m) * Kneppelberg (386.0 m) * Birkenberg (366.4 m) * Vorwohler Berg (360.2 m) * Moosberg (344.7 m) * Eichholzberg (341.5 m) * Döhrenberg (307.1 m) * Eimer Berg (ca. 300 m) * Kurzeberg (299.0 m) * Böhneberg (290.0 m) * Heisennacken (267.0 m) {{colend

Streams

The streams of the Elfas include: * Allerbach (eastern tributary of the Bewer) *

Bewer The Bewer is a river of Lower Saxony, Germany. It is a left, northern tributary of the River Ilme. It flows solely through the municipal territory of the borough of Dassel. Course The Bewer rises in the middle of the Elfas hills and is their m ...

(northern tributary of the

Ilme The Ilme is a left-bank, western tributary of the River Leine in Lower Saxony, Germany. It is long. The river begins at the pond in the centre of the Solling hills at an elevation of and flows initially northwards to Dassel, then in an easter ...

) * Hillebach (northern tributary of the

Krummes Wasser Krummes Wasser (in its upper course: ''Hillebach'') is a river of Lower Saxony, Germany. It flows into the Ilme in Einbeck. See also *List of rivers of Lower Saxony All rivers in the German state of Lower Saxony flow directly or indirectly into ...

) *

Lenne The Lenne () is a tributary of the river Ruhr in the Sauerland hills, western Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north a ...

(passes the Elfas to the west)

References

Georg Schambach
Wörterbuch der niederdeutschen Mundart
1858, p. 257 Axel Herrmann, Carsten Hinze, Volker Stein: ''Die halokinetische Deutung der Elfas-Überschiebung im südniedersächsischen Bergland'', in: ''Geologisches Jahrbuch 84'', 1967, pp. 407ff. Central Uplands Hill ranges of Lower Saxony Natural regions of the Weser-Leine Uplands Holzminden (district) Northeim (district)