232 REPORT— 1903. 



most interesting erratics yet recorded in England, such as the Norwegian 

 rhomb-porphyries and the Riebeckite-Eurite of Ailsa Craig, have never 

 been found in large blocks, and usually are little more than pebbles. 



The most conspicuous boulders in East Anglia are the dolerites and 

 basalts, which are by far the most numerous of the igneous boulders, 

 large or small ; and the writer is convinced, that the determination of 

 their places of origin would throw much light upon the difficult problems 

 of East Anglian glacial geology. Over a wide area from the east coast 

 of Norfolk to the Fens, and southward into Essex and Hertfordshire, 

 boulders of sandstone are very numerous : some of these, especially in 

 Norfolk, are derived from the Neocomian sandstone, while in the southern 

 part of the area blocks of brown sandstone are of very common occurrence, 

 which are for the most part of Tertiary age ; but whether all are from 

 the same source or not requires investigation. 



The discovery of rhomb-porphyry is not an absolutely new fact in 

 the geology of Norfolk, but the specimens recorded from Hellesdon and 

 Wymondliam are interesting, as they are the most southerly stations 

 known for this rock in Britain. 



The two examples of Laurvikite at Bacton and Happisburgh respec- 

 tively are the first records of this rock south of Lincolnshire. An endeavour 

 has been made to secure the Bacton specimen for the Norwich Museum. 



The present writer has long felt the need for some summary present- 

 ment of the vast mass of facts accumulated by this Committee and its 

 predecessor during the last thirty-two years, and he has therefore 

 prepared a synopsis of the whole of the reports from the year 1873 down 

 to and including the present one. The labour has been great, but the 

 advantage and convenience to students of glacial geology will, he hopes, 

 be more than commensurate. The records for Ireland have not been 

 included in this summary, as they were presented in tabular form in the 

 Report for 1902. Next year it is contemplated to publish a second part 

 of this synopsis, in which the distriV>ution of boulders of noteworthy rocks 

 will be analysed. 



Durham. 

 Communicated hy the Rev, W. J. WiNfiATE, of Bishop Auckland. 



Blackhalls (shore at) — 



Granite (probably Dumfrie.'!), porphyrite (Cheviot, typo), augen-gneiss, 

 gneiss, quartz porphyry. 



Bisliop Auckland Cemetery (in boulder clay) — 

 Carboniferous limestone. 



Barnard Castle (in bed of R. Tees) — 



Whin Sill, Carboniferous sandstone, andesitie ash (Lake District) 



Harj)erley (in bed of R. Wear) — • 

 Volcanic breccia (? Lake District). 



Piercehridge, ' The Greystone ' Boulder— 

 Andesitie breccia (Lake District). 



Oxenlovj — 



Andesite (Lake District) ■ 



