What structural feature develops in the core of high-mass stars as they sequentially fuse elements heavier than helium?

Answer

An onion-like structure of shells

Massive stars can sequentially fuse carbon, neon, oxygen, and silicon because their immense gravity maintains the required high temperatures, resulting in an onion-like structure of shells producing different elements.

What structural feature develops in the core of high-mass stars as they sequentially fuse elements heavier than helium?
evolutionlife cyclestarmass