REPORT OF THE DIRECTOR I916 4I 



conditions in the district have been prepared for the technical and 

 scientific press, preHminary to the complete report which it is 

 hoped will soon be ready for publication. 



The Edwards zinc district stands quite apart from the other 

 productive areas of the country, for the deposits are found in 

 Precambric (Grenville) limestones, about the lowest and oldest of 

 the geological formations that can be definitely recognized with a 

 place in the stratigraphic sequence. So far as known there are no 

 other active mines based on sulphide ores in this association, 

 although occurrences of similar type have been discovered from 

 time to time in the Canadian Grenville areas. The problems con- 

 nected with the derivation of the ores and the time of their intro- 

 duction necessarily are complicated by the vicissitudes of age. The 

 wall rocks have been subjected to intrusion repeatedly, have been 

 broken up, strongly compressed and metamorphosed, so that their 

 structure and original characters are most obscure, only to be 

 cleared up by careful study and weighing of the evidences. 



Miscellaneous. The demands upon the office for information 

 and guidance in matters pertaining to mining and mineral resources 

 have been particularly large in the last year or two, partly as a 

 result, no doubt, of the unusual commercial and industrial situa- 

 tion generally. Requests of this character are always given con- 

 sideration, and so far as compatible with the practice of the office 

 the desired information is promptly supplied. In many instances 

 this can be done by the mailing of a published bulletin, for which 

 only a nominal charge is made. It should be noted, however, that 

 the office does not undertake to supply analyses or ores and 

 minerals in competition with public laboratories, although there 

 seems to be a very general impression to the contrary. Samples, 

 however, may be submitted for identification and an opinion as 

 to their value, which can be given in most cases with a close 

 approximation to the truth upon the basis of experience and tests 

 that are readily applied. To carry out an exact analysis is the 

 work of one or more days and can not be undertaken except under 

 special circumstances where the matter is of unusual interest. 



PALEONTOLOGY 



The Museum. The work of installatioTi in the division of 

 paleontology was actively continued during the year. There were 

 added two cases in the hall of fossil plants, one large wall case in 

 the hall of vertebrates, and three cases in the hall of invertebrates. 

 Of the two new cases of fossil plants, one contains Devonian 



