THE 
AMERICAN NATURALIST. 
VoL. x1.— DECEMBER, 1877. — No. 12. 
THE CHINESE LOESS PUZZLE. 
BY PROFESSOR J. D. WHITNEY. 
i eee appearance of the first volume of Baron F. von Richt- 
hofen’s magnificent work on China! furnishes us with a 
suitable opportunity to put before the readers of the NATURALIST 
a brief account of one of the most curiously puzzling geological 
phenomena which has ever been brought to the notice of the 
scientific world, — the distribution and mode of occurrence of the 
so-called loess deposits of Northern China. The term loess is 
one in popular use in the valley of the Rhine for a peculiar 
loamy material ? which occurs over a considerable grea between 
Constance and the Belgian lowlands, having in places a thick- 
ness of as much as one or two hundred feet, and which is gen- 
erally admitted to have been a lacustrine deposit, formed when 
the Rhine was swollen by the melting of the great Alpine gla- 
ciers, which then extended much below their present level and 
covered a far greater area than they now do. Important as this 
formation is in that region, it sinks into insignificance when com- 
pared with what is presented by the Chinese deposits of similar 
character. 
The Chinese loess, like that of the Bias is an earthy sub- 
-stance of a brownish-yellow color, so tender and little coherent 
_ that it can be easily rubbed to a powder between the fingers. It 
is chiefly made up of argillaceous materials, with a small propor- 
_ tion of carbonate of lime; and it has also mixed with it more or 
less fine sand, the grains of which are quite angular. This sand, 
however, is small in quantity as compared with the argillaceous 
1 China, Ergebnisse mcg Reisen und darauf gegriindeter Studien, Erster eae we 
Binleitender Theil. Berlin, 1877. x 
2 Loess is very nearly the pia alent of the English word loam. Perhaps the best 
= Way to define it would be to say that loam when developed enough to become a for- . 
~ mation of geological importance, and not a mere surface deposit, is loess. 
aS Ai 
Copyright, 1877, by A. S. PACKARD, JR. 
