91色情片

A prominent geoscientist has won a battle to restore his reputation. Ronald
Dorn of Arizona State University in Tempe developed a technique to study ancient
rock art and stone artefacts by radiocarbon dating traces of organic material
embedded in rock surfaces. Some archaeologists questioned Dorn鈥檚 dating methods
after samples he sent to other groups were found to contain carbon grains of widely different ages
(New Scientist, 22 March 1997, p 10). But the US
National Science Foundation has now concurred with an Arizona State University
investigation that concluded Dorn did not tamper with his samples. 鈥淭he evidence
did not support allegations that Dorn added coal or charcoal to rock varnish
samples,鈥� the university report stated.