SECTIONAL TRANSACTIONS.—C. 443 
In the Eastern District there are also two beds of salt, but both are 
present in only a few places. Comparing different borings it is apparent that 
the main (upper) salt-bed at Middlesbrough is in the ‘Upper Permian Marl’? 
of Nottinghamshire, and the lower one in the ‘ Middle Permian Marl’ of that 
county. It has, however, been shown that the so-called Permian of Notting- 
hamshire passes laterally into Trias northwards, and it is believed that there 
is no Permian System in Britain. The horizons of these salt-beds are lower 
than those of the Western District, and they have probably a different origin. 
The Eastern deposits are associated with gypsum, anhydrite, and dolomite, 
whereas in the Western District only secondary gypsum is known. It is 
inferred that, while the Eastern salts were deposited in the (Zechstein) sea, 
the Western salts originated in lakes in a desert, at a somewhat later period. 
10. Miss M. Worxman.—The Permian Rocks of Skillaw Clough. 
Outcrops of Lower Permian rocks occur at Bispham, near Ormskirk, in 
Skillaw Clough, and also along Bentley Brook. 
The Millstone Grit described for comparison is found in Skillaw Clough, 
and forming a ridge of hills behind Parbold; its junction with the Permian 
is probably unconformable. 
In Skillaw Clough the Magnesian Limestone overlies purple-red fossiliferous 
marls resting on soft bright-red and hard brown sandstone; in Bentley Brook 
purple-red fine sandstone with shale bands is found above the Magnesian Lime- 
stone, which in turn overlies interbedded compact purple-red shales and sand- 
stones. The cementing material is calcite with dark-red limonite. 
The ‘heavy’ minerals include pyrite, magnetite, garnet, zircon, rutile, 
anatase, xenotime(?), tourmaline, ilmenite, hematite, hypersthene,* muscovite, 
epidote, chlorite, and monazite. 
‘The shale sandstones and grits of the Millstone Grit series contain the 
following ‘heavy’ minerals: Pyrite, garnet, zircon, xenotime (7), rutile, tour- 
maline, ilmenite (and other iron ores), hypersthene,* topaz, muscovite, chlorite, 
and monazite. This assemblage is very similar to that found in the Millstone 
Grit of Leeds by Dr. Gilligan, as well as to that of the Lower Permian of 
West Lancashire. There is also a great similarity between the latter and 
other Permian, whether found east of the Pennines or in Devonshire. 
As to derivation—the condition of the quartz, felspar, and garnets, and the 
presence of monazite indicate that the materials of the Permian came princi- 
pally from the Millstone Grit which had a northern origin. Some basic or 
ultra-basic rocks. probably of the Highland complex, must have furnished the 
hypersthene, epidote, and chlorite. The rocks were apparently laid down in 
an arid climate on the shores of an inland sea which afterwards covered them. 
11. Prof. G. Hicxrina.—The Tectonics of the Lancashire Coalfield. 
The paper gives some conclusions resulting from a study of the South 
Lancashire Coalfield (excluding the Burnley basin) by means of a precise 
contoured plan showing the present configuration of the surface of one stratum, 
the Trencherbone coal-seam. 
The Coal Measures attain a thickness of over 7,500 feet in the eastern part 
of the field. and show a striking westerly thinning to about 3,500 feet near 
Prescot. The greater part of this reduction is due to the dwindling of the 
Upper Coal Measures, in which both actual thinning of the measures (with 
loss of coal) and overlap by the Permian and Trias play a part. The Middle 
Coal Measures diminish from 3,500 feet on the east to 2,000 feet on the west. 
The coal-seams are brought nearer together by the reduction of the intervening 
strata, but little coal is Iost. On the other hand. the area of Middle Coal 
Measures south of Bolton and Bury is remarkable for the failure of the lower 
seams (below the Cannel). The Lower Coal Measures are believed to be fairly 
constant, with a thickness of about 1,500 feet. ; 
2 BR. UL. Sherlock. Relationship of the Permian to the Trias in Nottingham- 
shire. Q.7.G.S., vol. Ixvii., 1911, pp. 75-117 and pl. V, 
3 The first record for this system, 
