984 



SCIENCE. 



[N. S. Vol. XVI. No. 416. 



The Oeological Society of America will meet on 

 December 29, 30 and 31. President, N. H. Win- 

 ohell; vice-presidents, 8. F. Emmons, J. C. Bran- 

 ner; secretary, H. L. Fairehild, University of 

 Rochester, Rochester, N. Y. 



The National Geographic Society will hold a 

 meeting during Convocation Week. President, 

 A. Graham Bell; vice-president, W J MeGee; 

 secretary, A. J. Henry, U. S. Weather Bureau, 

 Washington, D. C. 



The Naturalists of the Central States will meet 

 on December 30 and 31. Chairman, S. A. Forbes; 

 secretary, C. B. Davenport, University of Chicago, 

 Chicago, 111. 



The Society of American Bacteriologists will 

 meet on December 30 and 31. President, H. W. 

 Conn; vice-president, James Carroll; secretary, E. 

 0. Jordan, University of Chicago, Chicago, 111.; 

 council, W. H. Welch, Theobald Smith, H. L. 

 Russell, Chester, Pa. 



The Society for Plant Morphology and Physiol- 

 ogy will meet during Convocation Week. Presi- 

 dent, V. M. Spalding; vice-president, B. D. 

 Halsted; secretary and treasurer, W. F. Ganong, 

 Smith College, Northampton, Mass. 



The Society for the Promotion of Agricultural 

 Science will meet during Convocation Week. 

 President, W. H. Jordan; secretary, F. M. Web- 

 ster, Urbana, 111. 



The Zoologists of the Central and Western 

 States will meet during Convocation Week. 

 President, C. B. Davenport, University of Chicago. 



THE GEOLOGICAL SOCIETY OF WASHINGTON. 



At the 132d meeting of the society, held 

 in Washington, November 12, the following 

 papers were presented: 



'A Deposit of Titanic Iron Ore from Wy- 

 oming,' by W. Lindgren. 



Recent and very valuable studies of deposits 

 of titanic iron ores have been contributed by 

 Kemp and Vogt. A perusal of these works 

 led to the publication of the following note 

 on Iron Mountain, Wyoming, which locality 

 I visited in 1896. 



Most of the deposits of titanic iron ore form 

 irregular masses or fairly sharply outlined 

 streaks in gabbro, or still more commonly in 

 anorthosite (labradorfels). Distinct., dikes, 

 undoubtedly indicating separate igneous in- 

 jection of molten magma of titanic iron ore, 

 have, however, also been described by Kemp 

 from the Calamity Brook district in the Adi- 



rondacks, and by Vogt from near Ekersund, 

 Norway, and the locality in Wyoming is 

 chiefly interesting as belonging to this type. 



Iron Mountain is situated in the south- 

 eastern part of Wyoming, about forty miles 

 north of Cheyenne, and in the foothills of 

 the Laramie Hills. It is eight miles west of 

 the railroaa station of Iron Mountain. The 

 rocks prevailing here are chiefly Paleozoio 

 limestones and sandstones, in rolling folds, 

 and these continue for six or seven miles up 

 Chugwater Creek. The dips here become 

 steeper and the underlying pre-Cambrian 

 rocks appear. As far as my observations 

 went they consist exclusively of a labradorite 

 rock of coarse grain which forms rough gray 

 outcrops. The rock can scarcely be called b 

 gabbro, for the pyroxene grains are very 

 sparingly distributed. It contains very little 

 magnetite or ilmenite. Going up one mile 

 farther, the chief deposit is encountered; it 

 crosses the canyon of the Chugwater as a solid 

 dike 100 to 200 feet wide, and can be seen 

 extending up several hundred feet in elevation 

 on both sides of the creek. The mass is said 

 to be traceable for half a mile north and 

 south of Chugwater Creek. The amount of 

 iron ore in sight is most remarkable. The 

 contacts are not exposed to best possible ad- 

 vantage, but have the appearance of being 

 sharp and well defined. The black titanic 

 iron ore seems entirely pure and free from 

 accompanying minerals; at least a search 

 along the base of the outcrop revealed no 

 other constituents of the mass. 



About 400 feet below the main deposit there 

 is exposed in the southern wall of the canyor, 

 a smaller dike only about ten feet wide. The 

 contacts are well exposed and show a medium 

 grained gray labradorite rock abutting sharply 

 against the dike of titanic iron ore. The 

 dike does not continue on the north side of 

 the canyon, the bottom of which is filled with 

 considerable debris. The greater part of the 

 width of the dike is composed of massive 

 titano-magnetite ; but adjoining the western 

 contact the iron ore for a width of one or 

 two feet contains large, imperfect crystals of 

 olivine imbedded in a cementing mass of the 

 black mineral. This association of olivine 



