Is a river canyon realistic here? Why or why not?

[waldronate]

My reading comprehension seems to be lacking in my old age. I interpreted the second set of dimensions as as part of the first set, for some reason. I was trying to get a notion of how much water was moving over the area.

The dimension values that you have there are quite plausible for a river canyon and there are multiple examples along the west coast of the Andes in the area you specified. New Zealand also has some examples of a better-watered landscape than the Andes, though on a somewhat smaller scale.

The topography on the map is from a synthetic noise generator and implies that there would be that sort of erosion all over the place because the area that you want to have as your canyon doesn't have much in the way of a catchment basin. A little handwaving from a geologic perspective could raise that central mountain area into more of a plateau and have a river collect water over the whole area and drop it off the edge of the plateau to cut that canyon. It would be a little like the Brahmaputra river in the Himalayas with that hard turn and radical change in character over a fairly small distance.

What is the intended character of this area The mountains are actively rising from somewhere to be that high, but is it intended to be mostly volcanic in origin or something like a batholith that's bring pushed up from below? In the case of the Andes, stuff is being shoved under an existing chunk of hard rock (it's why there's that wide part east of the Andes).

[eepjr24]

What is the intended character of this area The mountains are actively rising from somewhere to be that high, but is it intended to be mostly volcanic in origin or something like a batholith that's bring pushed up from below? In the case of the Andes, stuff is being shoved under an existing chunk of hard rock (it's why there's that wide part east of the Andes).

Batholith is a new word for me, but in reading the description that seems very much like what I would want. There would be some minor volcanic activity in this range, steam vents with maybe a hot stream or the like on the other side of the highest peak. Some spots might be as active as Yellowstone, but that would be rare. No above ground lava, etc.

This "island" is supposed to be on top of the line where two plates meet, which I think also fits with the batholith? The fault would run south-south east to north-north west on the island. Quakes would be a reasonably frequent occurrence, especially in the area of the southern most range.

Does most of that sound reasonable? Thank you for the assistance, I really appreciate it!

- E