The water supply of Oxfordshire, with records of sinkings and borings / by R.H. Tiddeman ... with contributions on rainfall by Hugh Robert Mill ... Pub. by order of the lords commissioners of His Majesty's Treasury.

  • Tiddeman, R. H. (Richard Hill)
Date:
1910
Catalogue details

Licence: In copyright

Credit: The water supply of Oxfordshire, with records of sinkings and borings / by R.H. Tiddeman ... with contributions on rainfall by Hugh Robert Mill ... Pub. by order of the lords commissioners of His Majesty's Treasury. Source: Wellcome Collection.

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    near Clayclon in the north, between Warwickshire and Northampton- shire, to the Thames at Caversham, near Keading, and readies 51 miles. This direction is not far removed from that of the general dip of the rocks to the S.S.E. throughout the county. The line of greatest width, starting midway in Oxford Clay, passes across the Cornbrash only and ends in the Great Oolite Series. That is to say it approximately follows the strike. In few parts does the county-boundary coincide ith any rock- boundaries or escarpments. It has certainly one great unmistakable physical feature all along its southern and south-western side. The Upper Thames from Kelmscot via Oxford, Abingdon, and Reading to Henley, forms a tortuous iuit obvious limit. From Kelmscot to Oxford the river runs along the strike on Oxford Clay, but from thence to Reading it flows in the direction of the dip of the Upper Oolitic and Cretaceous Rocks. The Cherwell does duty for the boundary for about nine miles only, from near Deddington northwards. There is an approximation to following a physical and geological feature along the Oolitic escarpment from Addlestrop by Great Rollright towards EdgehilTfor about 14 miles along a very old road. WATER-SUPPLY AND HUMAN HABITATION. Boundaries may be independent of streams for miles, but towns and villages are well known to group themselves along sources of water-supply almost entirely. The sources consist of streams, springs and wells. Streams, as a rule, run across pervious and impervious rocks equally, but wells are sunk in pervious rocks or must be deep enough to go through impervious rocks to reach pervious rocks. The facility of water-supply, in which we must include accessi- bility and sufficiency, has always been the prime factor in the choice of a site for human habitations. Therefore villages came to be established either on pervious rocks or on the boundaries between pervious and impermeable rocks. The exceptions to this rule in Oxfordshire are more apparent than real. The river-gravels and plateau-gravels are widely dis- tributed througliout the county, and are often more productive of water at a shallow depth than many of the pervious rocks. This explains the existence of towns and villages situated apparently on such unproductive formations as Oxford Clay. The sites are really on river-gravels, although these superficial deposits have not been depicted on some of the older geological maps. Oxfoi'd itself is a conspicuous exam])le of this, and the adjacent villages of Yarntoii, Cassington, and Eynsham are all built on gravel lying upon Oxford Clay. Leafield is another instance. Perched at a height of over 600 leet above the sea, on a remote outlier of Oxford Clay, it derives its water from an outlying patch of pebble-gravel resting on the clay. It is safe to say that but for that outlier of gravel Leafield village would not have been built, for the next available springs occur at lower elevations, and a village might have grown on the side but could hardly have been placed on the summit of the hill.