the -ti- in -titlan in placenames

[Anthony Appleyard]

  Frances Karttunen <karttu at nantucket.net> wrote:-
> -tla:n with a long vowel is a locative meaning 'place of, at.'  It doesn't
> take the ligature -ti-.  The short-vowel postposition -tlan 'at the base of,
> below, next to' takes -ti- when bound to nouns to form place names but not in
> ordinary postpositional constructions.  It can go either way with body parts.

Excuse a somewhat woolly idea, but I seem to remember hearing that -ti- can
mean "become", as in the placename Teo-ti-huacan = "god-become-place" = "the
place where men bacome gods". If so, could placenames of the type X-titlan
have originally meant "X become next_to" = "place where you come to be next to
X"? E.g. Tenochtitlan might have meant once "place where you come to be next
to rocks and prickly pears". Such precision in thinking by people naming
places seems to vary between different peoples: e,g, English-speakers might
set up a settlement and call it "Church Hill", and Welsh-speakers might call
it "Bryn Eglwys", routinely and unremarkably; but Nahuatl seems to realise
that a hill is one thing and a village is another thing, and would call the
settlement not "Teocaltepetl", but "Teocaltepec" = "_at_ the temple hill".