Geoscience Reference
In-Depth Information
20 individual scientific papers.
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None of Keller's critics contributed
an article; half of the chapters are authored or co-authored by prom-
inent critics of the Alvarez theory—Keller, MacLeod, Stinnesbeck. In
the topic, MacLeod and Keller sum up the foram evidence by
repeating their claim that two-thirds of the species went extinct
before the K-T boundary and the other one-third survived it. This
hearkens back to the original argument of Officer and Drake that
the change from the Cretaceous to the Tertiary was not instanta-
neous, but took place over an interval of time.
Most of the "Cretaceous" foram fossils that Huber studied from
ODP Site 738 he found to persist above the K-T boundary. Did
these species survive into the Tertiary or were they reworked? That
is the question. If large numbers made it through the K-T event to
live on in the Tertiary, they were not killed by a meteorite impact at
K-T time but died later from other causes, falsifying prediction 2 for
the forams. Thus the key question is whether the "Cretaceous" foram
species found above the K-T boundary had already died out and
were reworked into the Tertiary, or whether they actually survived
the boundary event to die thousands of years later. Keller and
MacLeod have addressed this question in a series of papers based on
studies of K-T sections from around the world, testing for survivor-
ship using techniques from paleontology, biogeography, and geo-
chemistry. ODP Site 738 was among their most thoroughly studied
cases. They concluded that there is no causal link between mass
extinction event and direct effects of K-T boundary impact.
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As a youngster growing up on a farm in northern Ohio, Brian
Huber could never have imagined himself on a research vessel in a
spot so remote as to be called Desolation Island. Better known as Ker-
guelen, this tiny dot just off Antarctica, deep in the southern Indian
Ocean, was long an important stop for whalers and seal hunters. (For
a superb fictional account, read Patrick O'Brian's
Desolation Island.
46
)
Huber was there as a paleontologist on Leg 119 of the Ocean Drilling
Program, which sailed from Mauritius in December 1987. During
Leg 119, hole 738 was drilled in the seafloor off Kerguelen, giving
Huber an enduring interest in this site. When the voyage began, like
most paleontologists, he was dubious about the Alvarez theory. As he
tells it, however, when the section of the core that traversed the K-T
boundary was drawn to the surface and laid out on the deck, his
doubts vanished. There, as at Gubbio, was the dramatic color contrast
between the white, foram-rich sediment below and the fossil-poor,
reddish section above. You could lay a knife blade right on the bound-
ary, exactly where an iridium spike of 18,000 ppt, one of the high-
est ever measured, was later found. The boundary clay displays fine
