ON THE LOWER PALEOZOIC ROCKS OK ENC4LAND AND WALES. 110 



The broken condition of the quartzite at the southern end of the 

 section is probably due to the proximity of a strong longitudinal (N.B. 

 and S.W.) fault (' The Koad Fault,' Lapworth), which separates the 

 Uriconian of Caradoc Hill from the Cambrian and Ordovician rocks of 

 the Cwms. 



The fault in the section itself is one of the minor fractures, transverse 

 to the major faults which determine the orographic features of the district. 



The fossils from the Mottled beds and Greenish-grey sandstone are of 

 considerable interest as representing the oldest-known fauna of the dis- 

 trict, and may be compared with those collected by Dr. Groom from the 

 Quartzite and Hollybush Sandstone of the Malvern area. 



The gradation, by intercalation, from quartzite below to sandstone 

 above, and the occurrence of the conglomeratic beds, confii-m and supple- 

 ment the observations made on Excavation No. 4 ^ at the north spur of 

 Little Caradoc, Comley. 



Excavation No. 54. — The Middle Ridge in the Cwms, about 150 yards 



South of No. 53. 



A trench was cut across a knoll where some hard grit protruded, and 

 a short summary of the section obtained was published in the report of 

 the Birmingham Meeting. The section confirms and supplements those 

 of the Quarry Ridge at Comley.^ The complete section is as follows : — 



Eastern End of the Section. 



Middle Cambrian. 

 e. Shale, with bands of hard glauconitic grit. Gj. The Quariy Ridge Shale. 



63. Clay with fragments of shale. ft. in. 



e-i. Band of hard, ringing, glauconitic grit 16 



e,. Brownish shale crushed and fractured 2 



d. Hard, ringing, glauconitic grit in beds from 3 to 24 inches thick. Cj. The 



Quarry Ridge Grit 28 



c. Conglomerate, c/. The Quarry Ridge Conglomerate. 



Cj. Brown pebbly somewhat incoherent grit, with small felsitic and 

 quartz pebbles, and a few rounded fragments of Lower Cambrian 

 Limestones • ^ ^ 



C3. Coarse conglomerate, incoherent and usually dark in colour, with 

 many subangular blocks of Lower Cambrian Limestones, among 

 which are fragments of the granular portion of the Black Limestone. 



c^. Dark rotten -stone, chiefly consisting of grains of quartz and glauconite 1 

 Acrothele sp., Acrothyra sp., HyolithdlMS and many fragments of 

 Trilobites. 



c,. Black skin of phosphatic material, partly adherent to the next bed 



below and partly invading the grit above, thickness variable up to 2 



Lower Cambrian. 

 h. Black, Grey, and OleneUus Limestones. 



65. Black Limestone, granular and phosphatic . . . ... 04 



64. Black Limestone, compact and crowded with fragments of Trilobites. 



Protolenus sp., Callavia sp .00 



6j. Dark purple compact Limestone, weathering to a yellowish clay ; 



trilobite fragments plentiful .06 



b... Dark purple compact sandy Limestone with abundant minute mica 



flakes 10 



Callavia callavci Lapworth (?), Anomocare pusiidatum Cobbold, 

 Microdiscus attleborensis S. & F., Obolella, Micromitra labradorica, 

 M. sp. and Ostracoda. 



2 Rep. Brit. Assoc. 1908, Dublin (1909), p. 238. 

 ' Rtp. Brit. Assoc. 1908, Dublin (1909). Excavations Nos. 1 and 2, pp. 234, 236, 



