Are the Young Kingdoms of Elric set on a disk world?

Question

The Geography of the Young Kingdoms described by Moorcock is somewhat vague, reading the works of Elric.

Chaosium inc. published a map (here a courtesy link for reference) which they admit is a rendition of what the Young Kingdoms may look like, although they changed in depiction through the works of Moorcock. The map is, of course, not a complete depiction of the world and not a planisphere at all.

In Atlas of the Young Kingdoms (published by Chaosium, ISBN 1-56882-021-6), on page 7, it is said:

The Plane of the Young Kingdoms is essentially a flat, oval disk, about 15,000 miles [...] north to south. Because it was created by Chaos, the influence of which remains strong to this day, the earth does not always conform to natural laws. [...]

On this plane, the edge of world is real, and not the product of superstition. It is a terrible place of rushing waters and empty void which only few people have seen.

Richard Watts, in his introduction to the volume published in 1994, says that they based as much as possible of the geography on Moorcock's canon, but filling the gaps for added value to those playing their RPG.

I'm looking for help tracing what of these facts on the Young Kingdoms back to canonical sources.

Answer 1

This is, for now, only a partial answer. I hope I'll be able to add more detail to it in the future.

The world is bounded or limited somehow by a region of Chaos. This is implied in The Vanishing Tower but says nothing on the flatness.

In The Vanishing Tower we found reference to the story of Aubec of Malador, from the Klant Province in Lormyr, who fought at the Rim of the World and conquered new lands from Chaos.

In The Vanishing Tower it is also implied that, once, Lormyr was the Rim of the World, although the Rim is not a fixed boundary: servants of Chaos may come from outside the Rim.

When Moongloom and Elric reach the castle (Kaneloon?) where Myshella is sleeping a magic sleep, they both are marvelled to find such an ancient castle in what was called the Rim of the World.

Myshella later will tell Elric that Umbda and the Kelmains are coming from beyond the Rim of the World. (the norther region of Lormyr) She specifically tells that Umbda comes from the lands beyond the Rim, implying there is land there, and somehow it is possible to magically cross the Rim and communicate with such lands.