Notes on Recent Borings for Salt and Coal in the Tees District

Abstract

Since the publication of Mr. E. Wilson's exhaustive paper on the Durham Salt-district, commercial enterprise has given an impulse to exploration, so that now the number of boreholes is over sixty. Most of these simply emphasize the knowledge derived from earlier work, with which they coincide. Three or four, however, may possibly contribute a few geological facts of interest, in relation to ( a ) the area of the Tees Salt-field and ( b ) the determination of the southern limit of the Durham Coal-basin. 1. Whitehouse, Norton, No. 1 borehole .—This borehole is twenty two and a half miles due west of Messrs. Watson and Scrafton's Stone Marsh borehole, the most westerly boring shown on Mr. Wilson's map. 2 Its site is 76 feet above sea-level, as proved by a neighbouring bench-mark. Full details of the strata bored through will be found in the Appendix to the present communication. The horizon of the roek-salt in this district lies at the base of the Saliferous Marls, and the layer of salt invariably has above it a bed of anhydrite, usually underlain by a stratum of red marl left in a rotten state by the dissolving out of some constituent: this is the ‘rotten marl’ of the workmen, to the presence of which is due the collapse of many brine-wells. below the beds of pure and impure rock-salt comes the lower anhydrite, so that the salt-bearing stratum, wherever present, is sandwiched between two layers of anhydrite, and its horizon is never a matter of doubt for anyone practically acquainted therewith.