There's a really interesting looking paper available at Language Log on the origins of the the alphabet, the following is from the abstract:

Even more importantly, this evidence could shed light on the invention of writing and the alphabet, illuminating its "mythical" (rather than actual) time and location, which appears to have been understood as located at the celestial opening/"gateway" between Gemini and Taurus, where the Milky Way joined and became one with the vernal equinox and the equator – the midway point of the sun's track between upper and lower, the north and the south. That midway gate was the sacred spot where the sun/seed/Word was believed to have been born, and it pre-dates writing itself, since the Gemini Gate goes back at least to the Neolithic village of Catalhoyuk, with the headless Orion symbolizing the "heading stage" and birth of the seed of Emmer wheat. Thus, the Gemini Gate, with its sacred symbolism associated with gates, pi, and the birth of the sun/seed/Word, sheds light on the reasons the inventors of the Phoenician alphabet highlighted it as the juncture between the two loops of the alphabet (the northern and southern).

The appendix has a discussion on "a little known ancient zodiac called the Taghit Zodiac, which contains strong evidence linking it to both the Phoenician alphabet and the zodiac". The paper is 127 pages available in a PDF; haven't read it all yet but looks really interesting; especially the bit about the 'gateway' and its connection to the vernal equinox.

thanks jane

this looks interesting.. i will have to take a closer look when i am back.. thanks, james

Wow, this is heavy going! It's a pity that by bringing in everything from Neolithic cave inscriptions through Egypt, Mesopotamia, Persia to ancient China we rather end up with overkill.
Interesting that the Taghit alphabet (mentioned in appendix, at end) from eponymous locality in Western Algeria is in fact, with very few modifications, the present day Berber alphabet (tifinagh), which you can see on state buildings (e.g. post offices) and documents in Morocco, where it is now an official national language (called tamazight).
https://en.wikipedia.org/wiki/Tifinagh# ... %20Algeria.
The same script is seen in another article on origins of the alphabet quoted on the page you link to - ref. SPP246, plate 7b from Serabit El-Khadim in Egypt.

The galactic equator, as a great circle (middle of teh Milky Way) intersecting others like our ecliptic and our equator, is considered by astronomers to have been on the W/S solsticial axis in 1994 (most recent calculations, Chinese I think) or 1998 (NASA, back in 60s I if I remember). There is a distinction between the galactic equator (the great circle through our galaxy passing through our sun) and the galactic plane (because the sun is calculated as being slightly off the central plane of the galaxy as a whole); the difference is about 9" of arc fon the ecliptic. The galactic equator is used by some siderealists to provide an "anchor" for the sidereal zodiac (see the Astrodienst site on ayanamsha, most commonly placed between 5° and 7° sidereal Sag/Gem, depending on the sidereal astrologer - a number place it quite close to the popular Krishnamurti ayanamsha, and to Babylon Kugler III). Back in 1977 (Harmonics in Astrology), John Addey, though a tropicalist, saw it as the best bet for a sidereal reference point, being a great circle and being more fixed than any individual "fixed" star.
To bring the VP (rather than the summer solstice) to a conjunction with the sidereal "Gemini end", I think you would be looking at c. 4000-3500BCE.

I think the galactic equator is a useful line of enquiry for siderealists, but that our tropical zodiac was likely to have developed from horizon-watching from solstice to solstice, e.g. in Egypt or maybe Mesopotamia, initially for calendrical reasons. I can warmly recommend this set of articles, particulary the introduction and the first one (available free from Academia):
https://www.academia.edu/644213/Revolut ... Calendrics
In fact that first article, "Re and the Calendars" by R.A. Wells, would seem to support speculations about the intersection Milky Way/ecliptic around 3500BCE, as founding or reflecting the myth of Nut, Egyptian sky goddess as the Milky Way, swallowing the Sun in sidereal Gemini at the spring equinox and then "rebirthing" it in her gentital region at the winter solstice nine months later. Part of the Milky Way, or its ecliptic projection, would thus represent the Duat, the "underworld" (or more likely overworld) through which the Sun/Osiris had to travel to be reborn. I wasn't quite convinced about using the polar projection of Deneb onto the ecliptic to represent the rebirth, and found the stuff about horizon-watching, solstice to solstice, more convincing. But it's interesting, and along the same lines as you are suggesting.
Thanks for the link.
Graham