Geoscience Reference
In-Depth Information
Hildebrand and Boynton that the Yucatan peninsula location identi-
fied by Penfield and Camargo was the more likely candidate. Soon
after Hildebrand and Boynton announced in an article in
Natural
History^
1
that it was indeed the K-T crater and claimed partial cre-
dit for the discovery: "In 1990, we, together with geophysicist Glen
Penfield and other coworkers, identified a second candidate for
the crater. It lies on the northern coast of Mexico's Yucatan Penin-
sula, north of the town of Merida. The structure, which we named
Chicxulub [pronounced Cheech-zhoo-loob] for the small village at
its center, is buried by a half mile of sediments."*
In a letter to
Natural History
a few months later, reflecting
the scientist's vital interest in priority, Penfield took exception to
Hildebrand's claim, noting that
he
had "identified" the structure in
1978, and reminding readers of the words with which he and
Camargo had closed their 1981 presentation: "We would like to
note the proximity of this feature in time to the hypothetical
Cretaceous-Tertiary boundary event responsible for the emplace-
ment of iridium-enriched clays on a global scale and invite investiga-
tion of this feature in the light of the meteorite impact-climatic
alteration hypothesis for the late Cretaceous extinctions."
1
2
Whew! In 1981, only months after the Alvarez theory appeared,
and in public at a scientific meeting, a prime candidate for the K-T
crater had been identified, but no one had noticed. The Yucatan
structure thus had to be rediscovered a decade later, after hundreds
of person-years had been spent in the search. Poor timing may be a
partial explanation: The meeting at which Penfield and Camargo
presented their paper took place in the same week as the Snowbird
I conference, to which the pro-impactors naturally were drawn. It
turned out that the circular nature of the Chicxulub structure had
been discovered in the 1950s by Petroleos Mexicanos (PEMEX)
through the use of geophysical techniques. In the 1960s and 1970s,
probing for possible oil-bearing structures, PEMEX drilled the struc-
ture and extracted rock cores. According to the account of Gerrit
Verschuur, Penfield wrote to Walter Alvarez in 1980, right after
he read the original Alvarez paper, to tell him that the crater might
be located in the Yucatan, but he never heard back.
1
3
(At that time,
"Ever since the crater was named, uncertainty has prevailed over the proper trans-
lation of the Mayan word,
Chicxulub.
According to Mayan specialist George Bey of
Millsaps College in Jackson, Mississippi, there are two acceptable meanings: "the
place of the cuckold" and "the red devil." Since "red devil" is so evocative of the
actual event, it seems the better choice.
