Meteorites delivered Earth's gold

Young Earth was sprinkled with precious metals
physicsworld.com, Sept. 7, 2011‎
http://physicsworld.com/cws/article/news/47116

Where does all the gold come from? University of 
Bristol, ‎Sept 7, 2011‎
http://www.bristol.ac.uk/news/2011/7885.html

Meteorites delivered Earth's gold, by Leila Battison
BBC News, Sept 8, 2011‎
http://www.bbc.co.uk/news/science-environment-14827624

The paper is:

Willbold, M., T. Elliott, and S. Moorbath, 2011, The 
tungsten isotopic composition of the Earth’s mantle 
before the terminal bombardment. Nature. vol. 477,
no. 7363, pp. 195-198. DOI: 10.1038/nature10399
http://www.nature.com/nature/journal/v477/n7363/full/nature10399.html

A related paper is:

Marty, B., and A. Meibom, 2007, Noble gas signature 
of the Late Heavy  Bombardment in the Earth’s
atmosphere. eEarth. vol. 2, pp. 43–49.

PDF file at:
http://hal.archives-ouvertes.fr/docs/00/33/07/83/PDF/ee-2-43-2007.pdf

Yours,

Paul H.