[meteorite-list] Younger Dryas Impact Hypothesis Discussion Heats Up Again

[Paul H.]

The discussion about the Younger Dryas Impact has 
heated up again with a flurry of comments in the 
Proceedings of the National Academy of Sciences of 
the United States of America concerning the paper:

Israde-Alcántara, I., J. L. Bischoff, G. Domínguez-Vázquezc,
H.-C. Li, P. S. DeCarli, T. E. Bunch, J. H. Wittkef, J. C. Weaver,
R. B. Firestone, A. West, J. P. Kennett, C. Mercer, S. Xie,
E. K. Richman, C. R. Kinzie, and w. S. Wolbach, 2012,
Evidence from central Mexico supporting the Younger 
Dryas extraterrestrial impact hypothesis. Proceedings 
of the National Academy of Sciences of the United States 
of America. vol. 109, no. 13, pp. E738-E747
http://www.pnas.org/content/109/13/E738.abstract

The replies, which can be found at
http://www.pnas.org/content/early/recent , are

1. Blaauw, M., V. T. Holliday, J. L. Gill, and K. Nicoll, 2012, 
Age models and the Younger Dryas Impact Hypothesis.
PNAS 2012 ; published ahead of print July 24, 2012.

2. Boslough, M., 2012, Inconsistent impact hypotheses 
for the Younger Dryas. PNAS 2012 ; published ahead of 
print July 24, 2012.

3. Daulton, T. L., 2012, Suspect cubic diamond “impact” 
proxy and a suspect lonsdaleite identification. PNAS 2012 ; 
published ahead of print July 24, 2012.

4. Gill, J. L. J. L. Blois, S. Goring, J. R. Marlon, P. J. Bartlein, 
K. Nicoll, A. C. Scott, and C. Whitlock, 2012, Paleoecological 
changes at Lake Cuitzeo were not consistent with an 
extraterrestrial impact. PNAS 2012 ; published ahead of 
print July 24, 2012.

and 5. Hardiman, M., A. C. Scott, M. E. Collinson, and R. S.
Anderson, 2012, Inconsistent redefining of the carbon 
spherule “impact” proxy. PNAS 2012 ; published ahead 
of print July 24, 2012.

The reply to the above comments, which is also at
http://www.pnas.org/content/early/recent , is:

Israde-Alcantara, I., J. L. Bischoff, P. S. DeCarli, G. 
Domínguez-Vázquez, T. E. Bunch, R. B. Firestone,
J. P. Kennett, and A. West, 2012, Reply to Blaauw et al., 
Boslough, Daulton, Gill et al., and Hardiman et al.: 
Younger Dryas impact proxies in Lake Cuitzeo,
Mexico. PNAS 2012 ; published ahead of print July 
24, 2012.

A related paper is:

van Hoesel, A., W. Z. Hoek, F. Braadbaart, J. van der Plicht, G. M. 
Pennocka, andM. R. Drurya, 2012, Nanodiamonds and wildfire 
evidence in the Usselo horizon postdate the Allerød-Younger 
Dryas boundary. Proceedings of the National Academy of 
Sciences of the United States of America. vol. 109, no. 20, 
pp. 7648-7653.
http://www.pnas.org/content/109/20/7648.abstract

Best wishes,

Paul H.