30 PROCEEDINGS OF THE ANN ARBOR MEETING 



1917. Rhythms and the measurements of geologic time. Bulletin of the Geo- 

 logical Society of America, volume 28. pages 745-904. 



From this list it is evident that his personal research was limited in 

 its scope, and that it was devoted almost entirely to continental and lit- 

 toral sediments. In his studies of delta deposits he considered some ma- 

 rine sediments. Otherwise, except in an incidental manner, he scarcely 

 discussed marine deposits until it became necessary for him in his paper, 

 ^'Ehythms and the measurements of geologic time," to devote more atten- 

 tion to them, and he did not then add to knowledge of the origin and 

 classification of marine deposits. BarrelFs rough estimate of the area 

 now cohered by "the subaerial deposits of piedmont waste, of continental 

 l)asins, and of deltas'' is one-tenth of the emerged continental surfaces, 

 and that "adding this to the estimate of the deposits of arid climates 

 would give a fifth of the land surface as mantled by continental de- 

 posits." ■* Although this ratio was not persistent throughout the different 

 geologic epochs, the question logically raises itself. Why did he devote so 

 large a part of his energies to deposits that occupy relatively so small a 

 part of the earth's surface? The answer to this question may be found 

 in his early environment and in the geologic problems he there encoun- 

 tered, for they cast over him a spell that was never broken. 



When Barrell was only five years old his father bought a farm at Xew 

 Providence, Xew Jersey, and there Joseph made his home until he grew 

 to manhood. New Providence is situated in the Triassic belt of Xew 

 Jersey, on the outcrop of the Brunswick formation, the uppermost of the 

 three formations that compose the Newark group in that district. In this 

 connection it is interesting to note that there are in Barrell's writings 

 frequent reference to the Triassic deposits of the eastern United States, 

 and that he clearly had an extensive first-hand familiarity Avith them. 



When nineteen years old Barrell went to college at Lehigh, in South 

 Bethlehem, Pennsylvania. South Bethlehem is not actually within the 

 district from the study of which Barrell was later to make himself fa- 

 mous, but it is situated near the eastern edge of the outcrop of the Ordo- 

 vician formations, and he subsequently needed to use all the knowledge 

 he could command of that part of the Appalachians. His work for his 

 master's degree familiarized him with the Archean Highlands of Xew 

 Jersey and their extensions into Xew York and Pennsylvania, but he 

 found liis big problem in the Anthracite region, where he practiced mine 

 surveying with students after he became an instructor at Lehioh in 1893. 



* Jour. Geol., vol. 14. 1000. p. .!.".'">. 



