Response to Comments on "A Vestige of Earth's Oldest Ophiolite"

Comment on "A vestige of Earth's oldest ophiolite".

The claim by Furnes et al. (Reports, 23 March 2007, p. 1704) that Greenland metavolcanic rocks require Paleoarchean sea-floor spreading is incompatible with their own data. The purported sheeted dikes have the composition of pyroxenitic komatiite and could not have fed the adjacent ferroandesitic pillow lavas. Neither type has ophiolitic analogs, and both are likely ensialic.

Comment on "A Vestige of Earth's Oldest Ophiolite"

Furnes et al. (1) reported that a sheeted-dike complex they identified within the ~3.8billion-year-old Isua supracrustal belt (ISB) in Greenland provides the oldest evidence of oceanic crustal accretion by spreading. However, they did not alert readers that the ISB contains supracrustal rocks and mafic dikes of different ages (2, 3). They also failed to demonstrate that the proposed components ...

Response to Pearl's comments on principal stratification.

Dr. Pearl invites researchers to justify their use of principal stratification. This comment explains how the use of principal stratification simplified a complex mediational problem encountered when evaluating a smoking cessation intervention's effect on reducing smoking withdrawal symptoms.

Response to Reviewers ’ Comments

Response to Reviewer’s Comments

#2. It is unclear why the authors only consider dust: the same problem should exist for other sources of iron as well, or probably even worse, especially finer particles from combustion? Why not consider those? You could presumably do this rather easily, just assuming BC has Fe, and including the size distribution of BC? There are recent reviews of the size of combustion iron particles (e.g. Wa...