TRANSACTIONS OF SECTION C. 625 



extended over the area, or more probably having been deposited in an attenuated 

 form, and subsequently removed in the widespread denudation that preceded the 

 Trias. 



Appendix. 



The Igneous Rocks are divided by Mr. Rutley into Syenitic rocks (Croft Series) ; 

 Andesite and Andesitic Tuffs (Caldecote Series) ; Diorites, Andeaites (or Diorites 

 containing Augite), and Basalts (or Diorites containing Olivine), these three 

 occurring as intrusions in the Lower Silurian rocks, and appearing to graduate 

 into one another. The Croft series includes quartz-syenite and a rock intermediate 

 between quartz-syenite and quartz-diorite. The Caldecote Series includes (1) a 

 finely laminated greenish-brown rock, resembling a sandy mudstone, probably 

 an altered andesitic tuff; (2) a rock composed of rounded or corroded crystals of 

 triclinic felspar and quartz-grains in a dark felsitic matrix, and appearing to be a 

 lava-flow or dyke, which has taken up fragments of other rocks in such quantity as 

 to simulate a tuff (the quartz-porphyry previously referred to) ; (3) a compact 

 purplish-grey rock (the diabase previously referred to), consisting of crystals of 

 triclinic felspar and magnetite in a felsitic ground-mass, which contains minute 

 crystals, believed to be hornblende, in which case the rock would probably be a 

 hornblendic andesite. 



The rocks intrusive in the Lower Silurian Shales consist of diorite at Marston 

 Jabet, Griff Farm, Chilvers Coton, Stockingford Cutting, Oldbury, and Dosthill. 

 Others, as at Nuneaton Midland Station and in the Stockingford Cutting, are akin 

 to basalt in their composition. 



The breccia at the base of the Hartshill Quartzite is composed of fragments of 

 eruptive rocks and of slate in a purplish matrix. Quartz-grains constitute a large 

 proportion of the rock. The Hartshill Quartzite consists of irregular crystalline 

 grains of quartz with numerous fluid lacunae, with a few grains of felspar. Rarely 

 microcrystalline siliceous matter occupies small spaces between the quartz-grains. 



6. On the Halesowen District of the South Staffordshire Coalfield. 

 By Wm. Mathews, F.G.S. 



Details of seven hitherto unpublished sections of sinkings for coal in this dis- 

 trict were given in the paper, and the section of the Old Hawne pits, as set forth 

 in Beete Jukes's ' South Staffordshire Coalfield,' was referred to. These sinkings 

 may be divided into the following groups : — 



I. 



Sinkings near the western edge of coalfield, Wassell, Oldnall Ridge, 540- 

 GOO feet alDOve sea-level. The figures give the position of the top of the thick coal, 

 or the measures corresponding therewith : — 



Wassell . . . . . .106 feet above seas 



Oldnall 94 „ 



Beeches , . . , . .65 „ 



II. 



• Sinkings in the Halesowen Valley : — 



Manor 468 feet below sea. 



Witley 450 „ 



New ilawne 357 „ 



Old Hawne 342 „ 



III. 



Sinking on eastern edge of coalfield : — 



Rowley Station .... 86 feet below sea. 



It was shown that the Halesowen Coal-measures lie in a trough, with a steep 

 synclinal section from east to west ; and that the various seams which, in their 



1886. s s 



