Counterattack

Ifyou start to take Vienna—take Vienna. Napoleon Bonaparte

Th e first to offer a detailed attack on the Alvarez theory were not paleontologists, as might have been expected since they were apparently the most offended, but a geophysicist from Dartmouth College, Charles Officer (Figure 10), and his colleague, geologist Charles Drake. Officer had had a distinguished career as a seismologist in industry; Drake was one of the most respected American geologists, having been president of the American Geophysical Union from 1984 to 1986, at the height of the controversy, and also president of the Geological Society of America. They began their rebuttal with two papers in Science,' which together comprised a three-part plan of attack:

I . Falsify the impact theory by showing (a) that the K-T event took place at different times around the world (and therefore could not have been the result of an instantaneous global catastrophe), and (b) that the transition from Cretaceous to Tertiary fossil species was too gradual to be consistent with an instantaneous extinction. (I will call these arguments 1 a and lb, respectively.)

2. Show that the evidence of iridium anomalies, shocked minerals, and spherules was far from diagnostic of impact and often was not even consistent with it (argument 2).

3. Substitute for impact another process that explains the evidence at least as well and that does not rely on a nonuniformitarian deus ex machina (argument 3).

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