Borings for Salt and Coal in the fees Salt-District. 385 



9. "Microzoa from the Phosphatic Chalk of Taplow." By F. 

 Chapman, Esq., F.R.M.S. 



10. " On the Basalts and Andesites of Devonshire, known as 

 Felspathic Traps." By Bernard Hobson, Esq., M.Sc, F.G.S. 



The evidence in favour of the contemporaneous (non-intrusive) 

 character of these Permian (or Triassic) lavas is discussed, and the 

 improbability of the former existence of felspathic traps in the area 

 of the Dartmoor granite, as suggested by Mr. R. N. Worth, is shown. 

 The macroscopical and microscopical characters of the rocks are 

 described. The great majority of the rocks examined are olivine- 

 basalts, though mica-augite-andesite occurs at Killerton, near Exeter. 

 The presence of quartz-inclusions in the rocks of West Town, 

 Knowle, &c. near Exeter is shown to have misled De la Beche into 

 terming these rocks quartz- (* quartziferous ') porphyries. The 

 veins in the traps, mentioned by Mr. Vicary, and regarded by some 

 authors as intrusive felsite dykes, are found to be red-stained veins 

 of calcite and sandstone. 



11. " Notes on Recent Borings for Salt and Coal in the Tees 

 Salt-District." By Thomas Tate, Esq., F.G.S. 



The Tees Salt industry has expanded considerably since Mr. 

 E. Wilson's exhaustive paper was read in June 1888. 



The results of subsequent borings have in most cases simply con- 

 firmed previously ascertained facts, but the two boreholes with 

 which this paper principally deals, put down on the White House 

 estate, 3 miles due west of Stone Marsh, may be useful in relation 

 to the determination of (a) the area of the Tees Salt-field, and 

 (b) the southern limit of the Durham Coal-basin. 



After boring through 115 feet of Drift deposits and 151 feet of 

 Red Sandstones and Marls, the Saliferous Marls, at the base of 

 which the Salt-rock, when present, is usually found sandwiched 

 between two beds of anhydrite, were reached, having a thickness of 

 178 feet, but with no Rock-salt. The Magnesian Limestone for- 

 mation, only 299 feet thick, an unusually large proportion of which 

 is gypsum or anhydrite, was succeeded by grey sandstones, rich in 

 calcite, probably due to infiltration. The carbonaceous shales and 

 sandstones with bands of encrinital limestones below these, to- 

 gether with their contained fossils, determine their identity with 

 the Yoredale Series. Total depth, 1079| feet. 



The chief results are : — (1) the Upper Keuper Red Marls are 

 wanting (as in nearly every borehole north of the Tees) ; (2) the 

 Salt-rock is absent and the Red Marl overlying its horizon is not 

 1 rotten marl ' but compact ; (3) the Magnesian Limestone (299 feet) 

 is the thinnest complete section in County Durham ; (4) no coal is 

 found ; (5) the Yoredale Rocks are represented by 336^ feet of grey 

 sandstones and encrinital limestones, carbonaceous shales, ironstone 

 nodules and carbonaceous sandstones. 



An Appendix, containing full details of the two vertical sections, 

 accompanies the paper. 



