244 RESEARCH IN CHINA. 
in which we now find it. Its accumulation occurred contemporaneously in the deep canyon 
of the Huang-ho and on the heights of the Wu-t’ai-shan. This preliminary consideration 
leads directly to the conclusion that the loess owes its development to processes of for- 
mation which are not commonly assumed in reference to other deposits of like compo- 
sition and magnitude.* 
In quoting the preceding from the volume published in 1877, it is 
but just to von Richthofen to state that, as his studies in orogeny progressed, 
he modified his views regarding the age of the mountains of northern China, 
and in March, 1905, when the results of our observations were laid before 
him, he met the facts of physiographic history with appreciation of their 
significance. 
The assumption that the Huang-t’u was laid down on a surface having 
the present mountainous relief, we now hold to be mistaken. We recognize 
that the surface beneath the Huang-t’u formation is one of mature topo- 
graphic aspect, which could have developed only in a relatively low altitude 
with reference to the sea, and we are able to describe features of the moun- 
tains which must be assigned to a later epoch than that of the earliest 
Huang-t’u deposit. 
The conception that the loess has been laid down upon a region having 
the present strong relief of the mountains of northern China led von Richt- 
hofen to an extreme inference regarding the work of the wind as the 
principal agent involved in its distribution. The extraordinary situations 
in which the Huang-t’u is now found, on the slopes and even on the 
summits of hills, where it occurs sometimes in a thick and isolated mass, 
places the formation outside of any class of alluvial deposits, and its 
occurrences are sometimes such as to occasion difficulty even in attributing 
them to wind action. Nevertheless, von Richthofen correctly recognized 
the importance of the wind as a dominant agent in the production of 
the loess; that is, in the sorting and local distribution of the fine dust of 
which the loess proper consists. By sound inference from the conditions 
now existing in the steppes of central Asia, he rightly ascribed the unusual 

*China, vol. 1, p.64. “Es ergibt sich in der That das iiberraschende Resultat, dass der Léss in 
seiner verticalen Verbreitung von der Meereshéhe unabhangig ist und, mit Ausnahme einzelner trennender 
Gebirgskamme, tiberall angetroffen wird, wo eine Grundlage fiir ihn vorhanden ist—vorausgesetzt, dass 
er nicht entweder hinweggespiilt oder von Alluvialboden bedeckt ist. Nun lasst es sich nachweisen, dass 
seit der Zeit seiner Bildung nur geringe relative Niveauveranderungen im nérdlichen China stattgefunden 
haben. Im Grossen und Ganzen was zur Zeit seiner Entstehung die Oberflachengestalt des Landes 
nahezu dieselbe wie jetzt, das Gesammtniveau aber hdher als gegenwartig, und somit die Kustenlinie 
weiter in das Meer hinausgeschoben. Der Léss unterscheidet sich daher von allen anderen in ahnlicher 
Machtigkeit auftretenden Formationen durch den bemerkenswerth Umstand, das er sich von Anfang an 
in denjenigen relativen Hohen abgelagert hat, in welchen wir ihn jetzt finden. Seine Bildung fand gleich- 
zeitig in dem tiefen Einschnitt des Hwang-ho und auf den Héhen des Wu-tai-shan-Gebirges statt. Schon 
diese vorlaufige Betrachtung leitet zu dem Schluss, dass der Léss seine Entstehung Bildungsvorganges 
verdankt, wie man sie bei anderen, aus ahnlichem Material bestehenden und eine ahnliche Machtigkeit 
erreichenden Formationen anzunehmen nicht gewohnt ist.’’ 
