96 



SCIENCE. 



[N. S. Vol. V. No. 107. 



nesia, the latter being often weighed with 

 the former. He cited cases of such error, 

 especially in German analyses. Mr. Mer- 

 rill, in reply, regarding migrating iron ox- 

 ide, stated that where air has free access, 

 iron is permanent, hut that below the sur- 

 face it is a very restless member. As for 

 phosphoric acid its quantity is small and it 

 is a peculiar ingredient, not always acting 

 the same in different suites of analyses. 



Mr. Merrill's paper was a suggestive and 

 important one and has a close bearing on 

 the origin of soils. 



The Age of the White Limestone of Sussex Co., 

 N. J. J. E. "Wolff, Cambridge, Mass., 

 and A. H. Brooks, Washington, D. C. 

 After a brief review of previous work 

 and opinions regarding this question, the 

 authors gave the results of their own 

 detailed work which led them to believe 

 that the limestone is of pre- Cambrian age. 

 By means of a map the areas throughout 

 Sussex county, N". J., were outlined and 

 the location of crucial sections indicated. 

 These were separately plotted and inter- 

 preted as indicating fault lines along which 

 the blue and white crystalline limestones 

 had become mixed up together, affording 

 apparent transitions. The thin bed of 

 quartzite that lies below the blue Cambrian 

 limestone was found extremely serviceable 

 as an aid in stratigraphic work. The out- 

 crop of it that dipped into the white lime- 

 stone east of the Buckwheat mine had 

 been shown by a recent quarry to run 

 down into the latter, to be tapering off and 

 to contain limestone boulders. It was re- 

 garded as produced by the filling of a crev- 

 ice by the advancing sediments. The ore 

 body was interpreted as interstratified in 

 the limestones because its elongation con- 

 formed to the pitch of the foliation of the 

 the metamorphic rocks. Eruptive granites 

 cut all the latter, although not the Cam- 

 brian limestone. In discussion J. F. Kemp 



spoke of the difficulties of the problem and 

 the gratification all must feel to have the 

 relations so well explained. Although the 

 evidence at Mt. Adam and Mt. Eve had 

 seemed to him to favor the metamorphism 

 of the blue limestone there, he had felt able 

 to go no further than probability in the 

 matter. He also commented on the very 

 puzzling nature of the ore bodies and the 

 strong probability that they were replace- 

 ments. 



The section then adjourned for lunch. 



When the section reassembled after lunch 

 the first paper read was the following pre- 

 sented by F. D. Adams. 



Origin and Relations of the Grenville-Hastings 



Series in the Canadian Laurentian. F. D. 



Adams and A. E. Baebour, with an added 



note by R. W. Ells. 



The paper sketched the distribution of 

 the fundamental gneisses in Canada. In 

 the field recently covered in Ontario the 

 rocks were described in detail and as con- 

 stituting plutonic members of various acid 

 and basic types, now stretched and gneissoid. 

 A map was used to show the areal distribu- 

 tion. The contact of the Grenville series 

 and the fundamental gneiss is an igneous 

 one. The carrying of the work over the 

 intervening belt to the Hastings areas gives 

 ground for thinking that the Grenville con- 

 sists of portions of the Hastings which have 

 become involved in the fundamental gneiss 

 during the intrusions of the latter. There 

 has been more or less absorption by infu- 

 sion of the Grenville into the gneissic 

 magma. An added paper by E.. W. Ells 

 described an area to the westward where 

 similar conclusions have been reached. 



In discussion C. H. Smyth, Jr., remarked 

 the coincidence of the views expressed with 

 his conclusions in the western Adirondacks. 

 J. E. Wolff asked for further particulars re- 

 garding the field evidence of the intrusion 

 of the fundamental gneiss into the lime- 



