728 ABSTRACTS OF PAPERS 



OCCURRENCE OF PETROLEUM ASSOCIATED WITH FAULTS AND DIKES 



BY FEEDERICK Q. CLAPP 



(A'bstract) 



Several instances of the occurrence of petroleum along faults and dikes 

 were described geologically and witb reference to their place in the classifica- 

 tion of oil and gas accumulations. 



COLOR SCHEME FOR CRYSTAL MODELS 

 BY GEORGE HALCOTT CHADWICK 



(AJ)stract) 



The proposed scheme of coloring uses the primary colors for the different 

 axes and applies to the various faces colors determined by the axis or axes 

 which the face parallels, with such modifications as are necessary, especially 

 in the isometric forms. The way in which this plan works out for the pyra- 

 mids and prisms of the tetragonal and hexagonal systems suggests a query as 

 to whether the ordinarily accepted usage of the terms "first order" and "sec- 

 ond order" in the hexagonal system is not exactly the opposite of their appli- 

 cation in the tetragonal and possibly in need of rectification. 



NEW MINERALS FROM THE FATAS OF BRAZIL 



BY OLIVER CUM MINGS FARRINGTON 



{AbStrCLCt) 



Study of the Favas accompanying the diamonds of Brazil (analyses by 

 H. W. Nichols) shows the presence of two new minerals. One, geraesite, is a 

 hydrous barium aluminum phosphate more acidic than gorceixite; the other, 

 minasite. is a hydrous aluminum oxide, which fills a gap in the series of 

 hydrous aluminum oxides and shows important parallelisms between the 

 hydrous oxides of iron and aluminum. 



RESINS IN PALEOZOIC COALS 

 BY DAVID WHITE 



(Abstract) 



Resins are present in most coals, except possibly those of the highest 

 grades, the amount depending in general on the degree of concentration 

 (residual) resulting from the decay and reiluction of the attending plant 

 structures. Interesting examples of megascopic resins in coals from the Car- 

 boniferous of the Mississippi Valley and Montana indicate the presence of resin 

 in the Paleozoic coals in proportions probably as large as in the coals of the 

 Mesozoic and Tertiarv. 



