328 Reports and Proceedings — 



Thickness in yards. 



1. Dark red Sandstone 2101 



2. Ifton or St. Martin's Coal-measures.. 75 !p • rqr, i 



3. Red marls with calcareous matter . . 180 , ' ' ^ ' 



4. Green rocks and Conglomerates .... 125 J 



5. Upper Coal-measures 80 "| 



6. Cetn rock to Cefa coal 100 | 



7. Cefn coal to Lower yard-coal 270 )-Coal-measm'es, 665 yards. 



8. Lower yard-coal to Chwarcle coal . . 80 j 



9. Chwarcle coal to Millstone Grit .... 135 J 



1255 yards. 



A detailed description of the strata was next given, beginning 

 with the lowest, together with details of each coal-seam as worked 

 in various parts of the field. After describing the beds from the 

 Millstone Grit to the Cefn rock in the North Wales coal-field, the 

 author proceeded to notice the Upper Coal-measures and Permian 

 strata in the Shrewsbury area, and showed that no break exists 

 between the two, the former passing gradually into the latter. He 

 then discussed the probability of Lower Coal-measures existing 

 beneath the upper beds near Shrewsbury, and showed from sections 

 that the existence of the lower measures might be anticipated. A 

 similar inquiry as to the presence of the Coal-measures beneath the 

 New Ked Sandstone of the Vale of Clwyd should also, in the author's 

 opinion, be answered in the affirmative. 



The organic remains found in the different beds were briefly 

 noticed, and then the faults of the district were discussed at some 

 length. The principal faults run north and south, with an upthrow 

 to the east, but are crossed by lines of fracture running east and 

 west. 



In conclusion, the correlation of the strata in the North Wales 

 and Shrewsbury coal-fields, and especially of the coal-seams, with 

 the beds found in other parts of Great Britain, was discussed, and 

 a section was given to show the representation of the different 

 measures in various coal-basins. The author was disposed to adopt 

 four subdivisions rather than three only, as usually accepted, and 

 pointed out some of the characteristics of each subdivision. 



IL— May 27, 1885.— Prof. T. G. Bonney, D.Sc, LL.D., F.E.S., 



President, in the Chair. — The following communications were read : 

 1. "On the so-called Diorite of Little Knott (Cumberland), with 

 further Remarks on the Occurrence of Picrites in Wales." By Prof. 

 T. G. Bonney, D.Sc, LL.D., F.R.S., Pres.G.S. 



The Little Knott rock and its microscopic structure were briefly 

 described by the late Mr, Clifton Ward, who named it a diorite, but 

 called attention to its abnormal character. The author gave some 

 additional particulars, and showed that although the rock varies in 

 different parts of the same outcrop, and is not one of the most 

 typical representatives of the picrite group, its relations on the 

 whole are with this rather than with the true diorites. He also 

 called attention to the extraordinary number of boulders which have 

 been furnished by this comparatively small outcrop, and discussed 



