11542 B.C.E.
* Heliacal rising of Sirius is observed on Thursday the 29th of April
  from the Gulf island of Zylos (11542)
  [Jules Oppert]
* The seasons and the flow of the Nile with its consequent harvests
  coincide with the positions of the separate figures and the characters
  assigned to the constellations of the zodiac
  [C.F. Dupuis]
* Fall of Abhijit: Vega becomes too far removed from Celestial North
  to be considered the North Star as it was when the Age of Virgo began
  (with the sun in Virgo during the harvest of 'her' wheat in Egypt
  where it is known as Maat in the constellation of The Vulture)
  having been already 4.5 degrees away at its closest approach ~12400
  [Sakadvipi-siddhanta. (J.F. Hewitt)]

* The Sphinx is built to herald the transition from the Age of Virgo
  to the Age of Leo
  [Robert Schoch, Ph.D. Geology & Geophysics, Yale University]
* Celestial North makes closest approach to iota Herculis
  9900 B.C.E.

* Megalithic temple to Cygnus built at Goebekli Tepe out of limestone
  [Dr Klaus Schmidt, Archaeologie, Uni Heidelberg]
* Great Pyramids of Egypt & China built at the closing of the Age of Leo
  "The Persians and the great mass of Magi relate that
   the inhabitants of the West, when they were warned by their sages,
   constructed buildings of the King and the Giza Pyramids. The traces of
   the water of the Deluge and the effects of the waves are still visible
   on these pyramids halfway up, above which the water did not rise."
  [Nubian Museum, Nagadan egg; Al-Biruni, Vestiges of Past Generations.] 

  8700 B.C.E.
* Age of Cancer begins
* Great Flood caused by a comet that had split up before striking the
  earth in Shoemaker-Levy fashion
  [Drs Alexander & Edith Tollmann, University of Vienna; thereby
   substantiating a hypothesis of Edmond Halley (vindictively censured by
   the Royal Society, yet nonetheless affirmed in John Martin's painting
  'The Eve of the Deluge'--featuring a comet as being responsible)]
* Manu Swayambhu builds a wooden ark & boards it with seven sophoi, called
  the Rishis; after the Deluge, he becomes the first king in India, and the
  Rishis become the seven stars of the Big Dipper  
  [Mahabharata.]

* Celestial North makes closest approach to tau Herculis
  7500 B.C.E.