Vol. 69.] TWO DEEP BOEINGS AT CALVERT STATION. 309 



the Eastern Boring), beginning with cores 18 inches in diameter, 

 with the view of reaching a depth of 2000 feet if necessary. The 

 actual depth reached was about 1398 feet, in April 1912. The old 

 boring was restarted, with cores 2 inches in diameter, at 446 feet 

 and continued to 649 feet by ^November 28th, 1911, when it was 

 stopped. 



We are very greatly indebted to Mr. A. Hiorns Jr., resident 

 engineer to the Guildhall Syndicate, for allowing us opportunities 

 to examine and take samples of the cores ; for the readiness 

 with which he has given us information on matters that we could 

 not investigate personally ; and for having carried on the Eastern 

 Boring, in the hope of adding to geological knowledge, after the 

 prospect of economic success was at an end. 



During the progress of the boring, one of us paid seven visits, at 

 intervals between September 1911 and April 1912; but some of 

 these visits were limited to so short a time, that the examination 

 of the cores was much less thorough than was desirable. Mean- 

 while the other author, accompanied by Mr. J. M. Muir, proceeded 

 to Calvert in December and January, to examine and collect 

 from the cores for the Geological Survey. The two series of 

 observations and collections were thus to some extent supple- 

 mentary ; but, owing to the confidential nature of the information, 

 no comparison of the results was possible until after the former 

 author had completed a paper and presented it to the Society. At 

 the suggestion of the President (Dr. Strahan) he then examined 

 the material collected by the Survey, and discussed the correlation 

 of the strata with the second author. As a result some modifi- 

 cations in the interpretation became necessary ; but, as the key to 

 part of the Jurassic sequence lay in certain unpublished information 

 obtained by the Geological Survey during the excavation of the 

 Eritwell railway-cutting, it was seen that only by a joint paper 

 could the boring be adequately dealt w T ith. Hence the present 

 communication. The parts that are the work of either author 

 exclusively (or almost so) are indicated by his initials. 



While each of us is generally responsible for the identification of 

 fossils in the sections which he has initialled, acknowledgment of 

 kind assistance must be made to Mr. S. S. Buckman (w r ho identified 

 all the ammonites and several of the brachiopods), to Dr. Kitchin, 

 Dr. Matley, and Mrs. Shakespear. We must also acknowledge 

 the help in the correlation of the Oolites derived from the papers 

 of Mr. E. A. Walford and Mr. L. Bichardson, to which one of us 

 must add his thanks to the former gentleman for personal exposition 

 of the Sharp's Hill section. The photomicrographs were taken in 

 the Research Laboratory of the Imperial College of Science & 

 Technology by Mr. H. G. Smith, B.Sc, to whom we are much 

 indebted. To Prof. T. T. Groom one of us is indebted for the loan 

 of Malvern specimens, for comparison with the sills passed through 

 in the boring. 



A selection of cores has been secured for the Museum of the 

 Buckinghamshire Archaeological Society, at Aylesbury. 



