During the successive stages of ice withdrawal and lowering of the water level, at the latter part of the last ice-age, some lakes were formed. Some of the stages were sufficiently stable to hold up the lakes long enough to allow laminated clays to be deposited on their floors over extensive areas. Such an example is Lake Milfield in Glendale. The lakes were impounded between the surrounding high ground, and it was either by the retreating ice front, or the Cornhill kettle-moraine that the deposition across the Till valley was made. When the lake was drained it was by a new channel that cut the deep ravine between Ford and Etal. The flat floor of the lake is less than 200 feet above sea level and is some 12 square miles in area.
In the Southern parts of the plain, sheets of coarse gravel have been spread out, by the Cheviot torrents, on top of the deep laminate clays of the lake. In the North there are extensive alluvial flats that are still liable to flooding. In the Eastern parts of Glendale traversed by the Beamish, sand and gravel are also very extensive, though the surface is more irregular and hummocky. Most of the area West of the Beamish, is a tract of kettle-moraine country, that is a medley of gravel mounds enclosing ill drained hollows (in this area a mass of stagnant ice was trapped, dumping its load of carried material upon melting).
Since the ice finally retreated streams have done an enormous amount of work, both in excavating their valleys in drift and rock, and transporting and sorting out the drift material. In this they have been assisted by considerable uplift of the surface. There are extensive terraces of rehandled glacial sands and gravels along all the main valleys. These are the work of late glacial flood water and are not truly part-glacial in the sense of being related to the sea level of North England after the evacuation of the country by ice had been completed, the
Glendale area being at the edge of the Cheviot volcanic rocks.
The Milfield Plain is relatively dry, having 30 inches of rain per year, as compared to the Lake District which is often in excess of 150 inches per year. The ground is firm and dry and is favoured for building upon compared with other areas of the Dales where the ground is prone to flooding. This area with its low altitude and the dryness, (being in a rainshadow area) combined with the extensive spreads of light gravelly soils, account for its relatively high proportion of arable land.
The Milfield Plain area is now an ordered and productive countryside compared with the wilderness of gorse that existed in the eighteenth century. This change was due to the agricultural revival of the late eighteenth and early nineteenth centuries which resulted in large farms that were untypical of the usual small Dale farms, only the Kimmerston Bog remains unclaimed in the area. Of all the Dales no others are so poorly endowed with mineral resources, as minerals of economic importance are not associated with any of the three geological formations that constitute this group of dales (except sandstone, that is quarried at a number of scattered locations, mainly for building purposes).
Due to the lack of minerals the Northern Dales have remained profoundly rural and sparsely peopled. Glendale experienced severe depopulation in the last century due to conversion from arable land to grass. This resulted in a drop of hired labour on the farms. The general loss of the population was in the order of 40%......................
All rather dry you may think but it sets the scene for the period in Milfield's history I find most interesting - ROYAL AIR FORCE MILFIELD.