Is "Little Foot" (StW 573) only 2.2 Myr-old?

[Daryl Habel]

All,

http://www.eurekalert.org/pub_releases/2006-12/uol-aar120706.php

According to this press release, scientists from the University of Leeds and Liverpool University have used "uranium lead chronology" dating techniques on stalagmites located above and below  the "Little Foot" skeleton, from which they have arrived at an age estimate of 2.2 Ma, a controversial result, since other methods of dating at Sterkfontein have suggested the age is closer to 3.5-4.0 Ma.

The paper is published in the journal Science, presumably today, but I have not yet caught up with it, so I can't  presently add much to this.

Dar

[Daryl Habel]

I've caught up with the Little Foot paper in  Science

Science 8 December 2006:
Vol. 314. no. 5805, pp. 1592 - 1594
DOI: 10.1126/science.1132916

Reports
U-Pb Isotopic Age of the StW 573 Hominid from Sterkfontein, South Africa
Joanne Walker,1 Robert A. Cliff,1* Alfred G. Latham2
Sterkfontein cave, South Africa, has yielded an australopith skeleton, StW 573, whose completeness has excited great interest in paleoanthropology. StW 573, or "Little Foot," was found 25 meters below the surface in the Silberberg Grotto. 238U-206Pb measurements on speleothems immediately above and below the fossil remains, corrected for initial 234U disequilibrium, yield ages of 2.17 ± 0.17 million years ago (Ma) and  Ma, respectively, indicating an age for StW 573 of close to 2.2 Ma. This age is in contrast to an age of 3.3 Ma suggested by magnetochronology and ages of 4 Ma based on 10Be and 26Al, but it is compatible with a faunal age range of 4 to 2 Ma.

1 School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK.
2 School of Archaeology, Classics, and Egyptology, University of Liverpool, Liverpool L69 3GS, UK.
* To whom correspondence should be addressed. E-mail: bob@earth.leeds.ac.uk

Available to Science subscribers HERE.

And I've even read it a couple of times.  But my understanding of the U-Pb dating technique is less than zero, so I cannot offer any meaningful comment on the findings.

Dar


 

[lagarvelho]

Dar:

What Science has is interesting, but there doesn't seem to be much more of it than there is on EurekAlert.
Anne G

P.S., I haven't read the article.  Yet.