('. C.VU.WY A V ON 111 i: UV AICIZI IIOS (IK SUKOCSIIIKi:. 7i")7 



Hill ;imi (inwards to the summit of the Ercal by the black colour of 

 Its soil. The decomposition of the voloanic rocks lias given rise t,<> 

 a brown soil thickly oovered with grass, shrubs, and trees, The dis- 

 integration of the quartzite, on the other hand, is mo slight, that the 



rock, where it is not hare, which is frequently the case, has (inly a, 



thin ooating <>r black oarbonaoeous matter, which supports but a 

 soanty vegetation. 



The thiokness of the quartzite, measured at the north east end »»t 

 the Eroal, and in the Last seotion (flg, 2), is about 200 feet, 



Lying to the west of the Wrekin, and oonneoted with the quarts 

 rocks just desoribed by a narrow isthmus, is an irregular area of 

 quartcite, 8 miles in Length from north cast to south west, and i.$ 



mile in its greatest breadth. Through these strata, are thrust- up 

 four bosses of bedded volcanic rock, the Largest of which is Charlton. 



Hill, with two small masses immediately i<^ the south, and a, Larger 

 exposure a mile to the south west. The dips ofthese quartzites are 



Very varied. In the road one third of a, mile south of the spot, marked 



44 Charlton Mill ° on the Ordnance map, they are displayed in a good 

 seotion dipping south easterly at 80°, and resting immediately upon 

 igneous rocks. Two or three hundred yards to the north-east is 



quartz rook resting On porphyry of the Charlton Hill boss, and dip 

 ping to the south at 45°, One third of a. mile to the south i^i' 



this last spot is another exposure o\' quartzite, dipping away to the 



south from the more southerly of the two small volcanic masses. A 



mile to the east north east of Charlton Hill, at the village of Rush- 

 ton, quartz-rock strikes north and south at a nigh dip; and a little 

 to the north west, of Unshton the dip is westerly. One third o{ a 



mile east of Rushton, in the quarry marked with an arrow ow the 



map oi' the Geologioal Survey, the <piart/.ife dips to the south at80°. 



These dips are too irregular to be referred to any one upheaving 

 force. Wherever the quartz-rook ocours in Ao^o proximity t*» 



igneOUS rocks, it dips away from them ; and it seems not impro 



bable that other dips at a. distanoe from exposed volcanic masses 



may be caused by local Upheavals of \oleanic rock which do not 



appear at the surfaoe. in tin- map published with my previous paper 



(vol, xxxiii. p. 654), there is no exposure oi' llollybush Sandstone 

 indicated wit bin I his area j but recent ly 1 have delected a small open 



ing of green sandstone, evidently BoILybush Sandstone, in the field 



io the south of the quartzite which dips io the south away from the 



most southerly oi' the three Charlton Hill bosses. This sandstone 



dips to the north that is, towards the quarty.ilo, which is distant. 

 about 100 yards. 



b. (\i('r-(\ir(((/or subarea. The quartzite reappears eight miles 



to the south west oi' the last area, on the southeasterly Hank of 

 Ca.er Caradoc, near Chinch Sfretlon, an igneOUS hill of similar eha- 



racter io some of the Wrekin rocks, ami evidently belonging to the 



same series. It is also loss distinctly exposed at the south west end 



of the south-east side oi' the Lawley, a volcanic hill oorth-east of 

 Caradoc, and separated from it b\ a gap about a quarter of ft mile 



in width. If the (piarl/ite is continuous under the superficial depo- 



