Excellent, excellent!
Did you ever come across this?
http://agutie.homestead.com/files/world_news_map/inca_ancient_calendar_andes.html
On another website I came across this paragraph:
In temples such as the one Benfer uncovered, the Andeans constructed offering chambers, used them for ceremonies and then built new chambers above the old. Benfer said this protected the Buena Vista site from looters, who came within one inch of the musician statuary while searching for gold and silver in the ancient temple. The well-preserved offering chamber holds ancient pieces of cotton and burned twigs, and Benfer’s team used the twigs to radio-carbon-date the various components of the excavation site.
http://www.newswise.com/articles/view/520388/#imagetop
“The well-preserved offering chamber holds ancient pieces of cotton and burned twigs...”
That’s exactly what was found at Caral! Methinks they were quipu - not ‘offerings’ but hidden for safekeeping.