■ - Abstracts of Papers read on Geology. 459 



streams represent the original head-waters of the river once flowing 

 through Blackheath, Oldbury, and Smethwick. 



The Rea basin possesses three eastward-flowing streams successively 

 diverted N.N.E. through Birmingham by a stream working back 

 along the Eea fault. Two of these were captured in pre-Grlacial 

 time, the third in consequence of glacial lakelet overflow. The 

 present thrice-notched ridge at King's Heath represents the pre- 

 Giacial land surface. The Middle Cole Valley is wholly post-Glacial. 

 The Lickey anticline has undergone elevation since the initiation of 

 the E.ea streams — i.e. in post-Tertiary time. It is crossed by three 

 waterworn gaps excavated pari passu with this uprise. The 

 southernmost of these now drains into the River Arrow. 



The Warley-Barr area is a region of Tertiary uplift, across which 

 rivers occupying the old pre-Triassic valleys have excavated deep 

 channels. All other streams in this area are very youthful. 



Conclusions. — The Trent drainage area has been subjected to 

 excessive piracy and has steadily suffered loss. Its sole gain is that 

 of the Penk at the expense of the Dee. The northern drainage is 

 consequent on the formation of the South Staffordshire anticline, 

 regarding the age of which it bears notable evidence. Speculations 

 as to the former north-west extension of the Thames drainage must 

 therefore be abandoned on reaching the area under consideration. 



(7) On some of the Basement Beds of the Geeat Oolite and 

 THE Ckinoid Beds. By Edwin A. Walfokd, F.G.S. 



80 WEBBY, in vol. i Mineral Conchology, describes a Brachiopod 

 now known as Rhynchonella concinna. It is figured on T. Ixxxiii, 6 

 from Aynhoe in Northamptonshire. A note on a quarry in the Great 

 Oolite made by the writer in 1883 fixes probably the source of 

 Sowerby's shell — 



Aynhoe Allotments Quakry. 



ft. in. 



1. Humus 13 



2. Whitish Marl 13 



3. Marl crowded with Rhynchonella concinna, Ostrea 



Sowerbyi, Natica, Modiola, Pholadoniya . 2 6 



4. Shelly Limestone, false-bedded .... 1 9 



5. Grey Marl 2 1 



6. Limestone, whitish : top course . . . ~ . 16 



The Geological Survey found its stratum to be a convenient line of 

 demarcation, as it rested upon a base of limestone graduating into the 

 Stonesfield Series. 



The discovery of other strata on the borders of East Oxfordshire 

 and West Oxfordshire necessitates the division of the Great Oolite 

 and the separation of the new beds proposed to be classed as Sub- 

 Bathonian. The old survey lines are thus sustained. The sequence 

 suggested is as follows : — 



Upper Great Oolite. — 1. Terehratula maxillata beds, 2. Calcaire 



a, EcMnodermes. 

 Lower Great Oolite. — 1. Striped Limestones. 2. Rhynchonella concinna 



beds. 3. Stonesfield Slate. 

 Sub-Bathonian. — 1. Striped Lirgestone and Crinoid beds. 2. Neeeran 

 ' Series. 3. Striped Crinoid Marls. 4. Chipping Norton Limestones. 



