>>20476
>But I still think a geologic explanation is the culprit, and data on wheter this orientation extends to the underground or is merely a surface phenomenon could clarify the mystery.

I couldn't easily find straightforward data even in Russian, most of internet articles talk about Altai mountains, but rarely discuss local plains.

Although some sources say that this type of terrain is common for West Siberian Plain. They use word "Грива" (literally "mane") that translates to "low ridge" or "dike ridge", but it even has no English wiki page and I don't have enough geological knowledge to find proper term.

>Flooding is unlikely to spawn this kind of terrain.

Some theories say that terrain like this may be formed because of flooding, although not average flooding of course: https://en.wikipedia.org/wiki/Giant_current_ripples