Antiquity of coca-leaf chewing in the south central Andes: a 3,000 year archaeological record of coca-leaf chewing from northern Chile.

Carbon-14 (14C) dating from mummies of the Alto Ramirez culture confirms that coca leaf chewing was an incipient practice among members of a population that peopled the valleys and coastal areas of Northern Chile by 3,000 years before the present (yr.B.P.). Out of eleven bodies from the burial site of Pisagua-7 (PSG-7, S 19 degrees 35', W 70 degrees 13') that were analyzed, two samples tested positive. Mummy 725-A C2 (dated 3,090 to 2,850 two sigma calibrated 14C years before the present) was shown to have a cocaine value of 13.3 nanograms/10 milligrams of sample (ng/10mg), and mummy 741 (2,890 to 2,760 two sigma cal yr B.P.), a 5.6 ng/10mg value.