622 



E. M. KIXDLE CANADIAN TLEISTOC'ENE CONCRETIONS 



Generali3ed section showing 

 ran^€ of concretions. 



Calcareous 



root 

 cancretjons 

 .?:hi30crelions) 



Pseudo- 

 -concretions 



--1] Torpedo-shaped 

 concretions of 

 non indurated day 

 Ftencil shaped" 

 concretions of 

 indurated clay. 

 cRhi30cretions i 



: I Roa^K surfaced 

 -i concretions 

 ^Kvitho'it fossiis 

 4i vMariekor'* 



angles to the l)edding of tlie clay. The concretions occurring at this 

 horizon show a large variety of forms. The majority of concretions with- 



u t radial symmetry 

 al)out a vertical axis have 

 a plane of symmetry par- 

 allel to the bedding of 

 the clays and never ver- 

 tical to it. Concretions 

 3 to (3 inches long, which 

 frequently inclose the 

 skeleton of a small fish 

 of similar length as a 

 nucleus, are common 

 among the concretions 

 of the latter type. In 

 these concretions the 

 shape of the outline is 

 controlled entirely by the 

 shape of the fossil (plate 

 8). These fish-inclosing 

 concretions have long 

 l^een known and may be 

 seen in various museum 

 collections. 3/ all o t u >< 

 rillosus is the fish gener- 

 ally found in th-em. Fre- 

 c|uently two or more fish 

 skeletons lying at vari- 

 ous angles to each other 

 give these concretions a 

 highly irregular shape 

 (plate 8, figures 3, 4). 

 The Survey collection of 

 these concretions in- 

 c 1 u d e s one specimen 

 which incloses the skull 

 and a portion of the spi- 

 nal column of a marten 

 fkjikk i.—Gciu',<,ii:r'i ottair,, piristo>a,r srtion (Marfcs amevicami amer- 



Showing the types of concretions characterizing dif- ^-^^^^^ Turston) (plate 8, 

 ferent parts of the section. Concretions are about one- 

 fourth natural size. figUreS 1, 2). The flat- 



Smooth surfaced 



concretions 



with 



Mailotus yi llosus 



and other fossils 



Olls.v.-i. River 



