The “veins of the world” in some cosmological notes from the 1930s (SM/241-2, 255), also appearing in The Etymologies as combination of mar “world” and the plural of talma “root” (Ety/TAL).
Qenya
talma
noun. base, foundation, root
talmar ambaren
place name. Roots of the Earth
martalmar
place name. Roots of the Earth
tyel
noun. end
Another name for Martalmar in cosmological notes from the 1930s (SM/241), a combination of the plural of talma “root” and the genitive of Ambar “world” (Ety/TAL).