140 Corresjwndeiice — Her. R. Ashhigton Bullen. 



careful consideration of any work that Professor Coleman had published 

 on it. I am not aware that his second report was available when 

 I prepared my address. Its issue was reported in Economic Geology 

 for June, 1906 ; but as the paper is not included in the Annual List of 

 Literature received by the Geological Society for either 1905 or 1906, 

 I presume Economic Geology was supplied with an advanced copy. 

 This view is supported by the fact that Professor Coleman, in a paper 

 in the Journal of Geology for last month, published six months after 

 the manuscript of my address had to be in the hands of the printer, 

 refers to his report as " recently distributed." I notice, moreover, that 

 tbere is no reference to it in Messrs. Campbell & Knight's paper on the 

 Microstructure of the Nickeliferous Pyrrhotites, which was received in 

 this country after my address had been delivered. As the repoi't was 

 apparently inaccessible to American authors, it is not surprising that 

 it was not available on this side of the Atlantic' 



My opinion as to the origin of the Sudbury ores is not so emphatic 

 as Professor Coleman's article would suggest. The opinion which he 

 quotes was introduced by the words "appear to have been," and the 

 next sentence continues the same expression of doubt — " if Dickson's 

 facts be right," etc. Without having been in the field, I should be 

 sorry to express a final opinion on either side. But so far as I am 

 capable of judging from the literature, the igneous origin of the ores 

 is not yet established, and is faced by greater difiiculties than the 

 alternative theorj-. Messrs. Campbell & Knight, in their recent paper 

 in Economic Geology (June, 1907), also conclude that "Dickson 

 has a weight of evidence to prove that his specimens are of secondary 

 aqueous origin" (p. 351). They claim that (p. 365) in all the chief 

 mining fields of nickeliferous pj-rrhotite the mode of origin of the 

 ores was the same, and that the basic rocks with which the ore bodies 

 are associated were first formed, then fractured, and then " ore-bearing 

 solutions came in and replaced the rock-matter wholly or in part by 

 pyrrhotite. Later on the pyrrhotite, etc., was also strained and broken, 

 and the deposition of pentlandite and chalcopyrite followed." Hence 

 I am not the only one who is not yet convinced that the igneous origin 

 of these ores is "the correct view." J. W. Gkegoey. 



Geological Depaktment, 



Univeksity, Glasgow. 

 January 31«<, 1908. 



KITCHEN-MIDDENS IN NORTH CORNWALL. 



Sir, — In Mr. B, B. "Woodward's interesting paper in the 

 Geological Magazine (January and February, 1908) on "The Drift 

 and Underlying Deposits at Newquay," he mentions kitchen-middens 

 and cooking-sites as occurring towards the upper parts of the deposit 

 of sand (Fig. 1, p. 15, January). It may be interesting to note the 

 similar occurrence in the Trevose district further to the north-east 

 of many such kitchen-middens and cooking-sites. In October, 1901 



' I am informed (Feb. 17th) that Professor Coleman's report has not even yet 

 been received at the Geological Society's Libraiy. 



