On the lower terrace of the great plateau we find an 1 In Vega Exped.
Above the terrace line, supported by 24 other columns.
This is the extent enclosed by the medieval walls; within them are considerable remains of the lofty terrace walls of the Eutruscan period.
The tributaries of the Amur (the Shilka with its affluent the Ingoda) become navigable only on the lower terrace of the plateau.
4 The lower terrace is obviously continued in the Tarim basin of East Turkestan; but in the present state of our knowledge we cannot determine whether the further continuations of the borderridge of the higher terrace (Yablonoi, Kentei) must be looked for in the Great Altai or in some other range situated farther south.