February 28, 1902 ] 



SCIENCE. 



351 



The second paper, entitled ' The Mesabi Iron 

 Eange,' was presented by Mr. C. K. Leith. 



Mr. Leith discussed certain new develop- 

 ments in the geology of the Mesabi iron range 

 of Minnesota. He showed that the Keewatin 

 series of the Minnesota Survey comprises two 

 distinct series — an igneous 'basement com- 

 plex' and a sedimentary series. The former 

 is classed as Archean and the latter as Lower 

 Huronian by the United States Geological 

 Survey. The district therefore shows a com- 

 plete succession from the Archean through the 

 Lower Huronian into the Keewenawan, and 

 in the fullness of the succession and in the 

 clear-cut unconformities the Mesabi may be 

 regarded as the type of Pre-Cambrian district 

 of the Lake Superior region. 



The iron ores result from the alteration of 

 certain peculiar rocks composed of aggregates 

 of minute green granules. The granules were 

 called glauconite by Spurr, and were supposed 

 to be of organic origin. The present investi- 

 gation, however, shows them not to be glau- 

 conite. They are composed essentially of fer- 

 rous iron and silica, and lack potash, a con- 

 stituent essential to glauconite. The granules, 

 it is believed, were developed in much the 

 same manner as the iron carbonates, which are 

 the original iron-bearing rocks of the older 

 iron districts. The iron (derived from the dis- 

 integration of older basic rocks) was carried 

 in a ferrous form into the ocean, which was 

 depositing iron formation material, and was 

 there precipitated as hematite or limonite, and 

 at the bottom of the ocean was again reduced 

 by organic matter to a ferrous form, and then 

 combined with silica, giving the substance we 

 now find. The occurrence of the substance in 

 granules is due to the same causes as the 

 oolitic structure in limestone. After the iron 

 formation, thus formed, emerged from the sea, 

 weathering and the concentration of the ore 

 began. The ferrous silicate was broken up and 

 the iron oxidized. As the work was done 

 through the agency of percolating underground 

 waters, the position of the ore deposits was de- 

 termined by the laws of flowage of such waters. 

 The deposits are now found in gently pitching 

 troughs formed by the gentle folding of the 

 iron formations and bottomed by slaty layers. 



or their altered equivalents, the paint rock, in 

 the iron formation. 



Dr. Whitman Ci'oss then made some com.- 

 ments on an article by Mr. Bailey Willis deal- 

 ing with stratigraphic classification. Dr. 

 Cross expressed the belief that a geologic map 

 should express as much of geologic develop- 

 ment as practicable; that a map whose carto- 

 graphic units were discriminated solely on the 

 lithologic characters of the so-called 'lithologic 

 individuals' was not entitled to be called a 

 geologic map. It was really a lithologic map. 

 He contended that in order to express geologic 

 development the units of cartography must 

 be established with due regard to all classes 

 of available facts, and that restrictions were 

 both undesirable and unnecessary. 



Alfred H. Brooks, 



Secretary. 



DISCUSSION AND GORRESPONDENGE. 



THE ENDOWMENT OF RESEARCH. 



To THE Editor of Science: In Science of 

 February 8, 1901, N. S., Vol. XIII., p. 201, 

 there is an article by Professor E. C. Picker- 

 ing remarking on and requesting suggestions 

 in regard to the reasons why there is so little 

 demand for grants from various funds which 

 are available for research. I had hoped that 

 some one with wide experience would have 

 some suggestions to offer on this subject. But 

 since no one, so far as I am aware, has pub- 

 lished a reply, I am moved to offer a few 

 thoughts of my ovrai. I feel inclined to do 

 so at this time because Mr. Carnegie has 

 just endowed research on a magnificent scale, 

 and, as some of the difficulties which have 

 confronted Professor Pickering will doubtless 

 confront the trustees of this fund, a discus- 

 sion of the matter seems particularly desir- 

 able. 



The lack of requests for research funds is 

 not because there is lack of desire to do re- 

 search work. There are plenty of students 

 eager to investigate questions in which they 

 are interested. More than a dozen have men- 

 tioned such a desire to me within the last ten 

 years. Two or three of these were Harvard 

 or Technology graduates, amply prepared by 

 training to carry on such researches. I have 



