Fkbkuabv 6, 1903.] 



SCIENCE. 



219 



that the Aniiuikie overlies both parts of 

 the Archaean uon-conforniably, (t) the 

 recognition of the igneous origin of the 

 green-sand of the Animikie, (j) the de- 

 termination of the igneous origin of the 

 jaspilytes of the Mesabi and Vermilion 

 ages, (fc) the addition of numerous min- 

 erals to the geographic area of the state, 

 (I) the determination of the metamorphic 

 origin of gabbro from Archcean green- 

 stone, and (m) of granite from Archtean 

 sediments. (2) Economic and educa- 

 tional: (a) Determination of the cause of 

 foul M'aters in the prairie region, (5) the 

 demonstration of the excellence of the 

 Hinckley sandstone and its consequent 

 M'ide adoption, (c) the discovery and an- 

 nouncement of the Mesabi iron ores, {d) 

 the distinction of the gabbro (igneous) 

 ores from the Mesabi iron range, (e) the 

 delineation of the Mesabi belt as distinct 

 from the Vermilion, which has facilitated 

 search and exploitation, and (/) the dem- 

 onstration of the utility of intrusting geo- 

 logical surveys to the state universities. 



Current Woi-h in Paleontology in New 

 York State: John M. Clarke, Albany, 

 N. Y. 



(a) The Guelph reefs and their faunas. 

 Recent investigations have shown an excel- 

 lent development of the Guelph fauna at 

 at least two stages in the Upper Siluric 

 dolomites of New Yorlj, and an analysis 

 of the character of the species and the 

 nature of the enclosing rock indicates that 

 the fauna flourished on and about coral 

 reefs in the shrinking sea. (h) The faun- 

 istic provinces of Portage time. In addi- 

 tion to the pi'ovinces already established 

 during this stage in New York, viz., the 

 eastern or Oneonta, the central or Ithaca, 

 the third or Naples (= true Portage). The 

 last proves to be divisible into sub-prov- 

 inces, depending upon the degree to which 

 this fauna, advancing from the west, pene- 



trated eastward. The migration path of 

 the faima is from the northwest. (c) 

 The causes of depauperation in pyrite 

 faunas. Investigation of the organic con- 

 tents of the sheet of pyrite lying in the 

 horizon of Tully limestone for a distance 

 of one hundred miles in western New York 

 gives some clue to the causes which have 

 effected like results in similar occurrences 

 of other age. {d) The determination of 

 the uppermost Cambric in eastern New 

 York. This pertains to the discovery of 

 the horizon of Dictyonema and Clonograp- 

 tus in Rensselaer County. 



On an Important but not Well-knoivn Lo- 

 cality Furnishing Cretaceous Fishes: 0. 

 P. Hat, American Museum of Natural 

 History. 



The paper called the attention of geol- 

 ogists and collectors to a locality in the 

 region about Yankton, South Dakota, from 

 Avhich Dr. F. V. Hayden obtained several 

 species of fossil fish for Professor E. D, 

 Cope. Most of the genera are related to 

 or identical with genera from Mount Leb- 

 anon, Syria. 



Quantitative Chemical-mineralogical Clas- 

 sification of Igneous Bocks: Whitman 

 Cross, J. P. Iddings, L. V. Pirsson and 

 H. S. Washington. 



The presentation of the subject embraced 

 a statement of the needs and the occasion 

 for such a classification of igneous rocks; 

 the principles on which it is based; the 

 method of procedure employed to produce 

 quantitative subdivisions of rock magmas ; 

 the method of expressing the actual min- 

 eral development (composition) and tex- 

 ture of the rocks; the nomenclature pro- 

 posed ; the proposition to establish a classi- 

 fication and nomenclature for use in field 

 work, and for general geological purposes. 

 The pj-esentation closed with a correlation 

 of the quantitative classification with the 

 one in use at present. 



