444 ME. H. KAY ON THE HALESOWEN SANDSTONE [Oct. I913, 



the Halesowen sequence, which is of great importance in regard 

 to the classification of the Series. Other pale-blue clays, which 

 are accompanied by ' coaly traces ' or impersistent thin coals and by 

 Spirorbis Limestone, also occur, but these can readily be proved to 

 lie at a higher horizon. 



The name of the Halesowen Coal and Clays may be 

 applied to these beds, the thickness of which varies from 10 to 

 50 feet, being greatest within the town of Halesowen. • 



(4) The Hasbury Group. 



Above the Halesowen Coal and Clays occurs a group of sand- 

 stones which present special features of their own, owing to the 

 presence of fragmentary foreign material. In the Lutley Valley, 

 in a lane near the Eiver Stour, and in Manor Lane, soft brown 

 sandstones are seen, in which transported peaty material occurs. 

 Above these are paler sandstones, speckled with indurated red marl 

 and with coal-dust. Higher beds contain small pellets of the same 

 materials, together with flakes of a peculiar white ash and tiny 

 quartzite-pebbles. In the old quarries near Yew-Tree Farm on 

 Hasbury Hill, the blocks contain so much of the marl that they 

 assume a dull purple hue, speckled with white, black, and yellow ; 

 and sandstones similar to these occur in the lanes and stream-course 

 near Illey Mill. 



A like succession of beds is found above the 1-foot coal in Ham 

 Dingle, but in Hodge-Hill Dingle and Wassel-Grove Dingle the 

 higher and redder beds are not exposed. Beds similar to those of 

 the two last-named localities are seen near the entrance to the 

 Lappal Tunnel. 



Along a line from Ham Dingle to Lushbridge and thence to the 

 northern parts of Hasbury Hill, the beds appear to be horizontal; 

 but south of a second line from Bog's Farm through the southern 

 portion of Hasbury Hill and the southern parts of the town of 

 Halesowen, the beds dip from 15° to 20° south-south-eastwards, 

 and disappear beneath a group of rocks which has still to be 

 described. From their characteristic development near Hasbury, 

 these beds are named the Hasbury Group. Their thickness 

 varies from 120 to 150 feet. 



(5) The Illey Group. 



The remaining portion of the Halesowen Series forms the group 

 separated by Prof. Lapworth under the title of the ' /Spiror&is- 

 Limestone Group.' In consequence, however, of the discovery 

 of that limestone at other horizons (p. 443), the group is now 

 re-named the Illey Group, from the locality whence it was 

 first described. 



The description given by Prof. Lapworth is as follows : — 

 ' A thin series of red, grey, and oli^-coloured shales and sandstones with 

 a band of Spirorhis limestone and a few thin coaly beds.' 1 



1 ' Sketch of tlje Geology of the Birmingham District' Proe. Geol. Assoc. 

 vol. xv (1898) p. 3m. 



