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Australasian tektite age paradox - Part 2 of 2

TAYLOR S.R. (1999) The Australasian tektite age paradox (MAPS 34-3,
1999, From the Editors, page 311):

A number of workers familiar with the Australian localities continued to
insist on a recent fall (e.g., Lovering et al., 1972) relegating the
awkward deep-sea microtektite data to a separate event. Their position
was reinforced by fieldwork by Izokh (1993) in Vietnam, clearly part of
the same strewnfield, where he claimed a 10 000 year age for the fall.
However work from Vietnam, reported by Fiske et al. (1996), has shown
that "the tektite-bearing horizon represents a paleo-erosional surface"
and "because the tektites are not presently in a chronostratigraphic
horizon, their stratigraphic age is uncertain" (p. 40). Studies in this
area are aided by the exposures in the myriad bomb craters resulting
from the Vietnam war. This information is possibly the sole beneficial
result of that expensive and ultimately futile bombardment.
Robert Fudali (1993) had previously drawn attention to the fact that
most australites showed signs of weathering and transport and that
perfect specimens constituted only a very small fraction of collections.
He noted that at the Port Campbell, Victoria locality, the australites
appeared to be coming from a deeper sandy horizon rather than the
present surface, all this suggesting that the young age was in error.
At this stage, GENE SHOEMAKER, long familiar with the tektite problem,
entered the scene. In conjunction with Ralph Uhlherr and assisted in the
field by his indefatigable wife, CAROLYN, he began mapping the Port
Campbell area. Gene was a superb field geologist whereas Ralph, who had
been collecting tektites in the area for many years, has an intimate
knowledge of the local geology. Their combined work (Shoemaker and
Uhlherr, 1999) has pinned down the precise horizon, the Hanson Plain
Sand, from which the tektites found in younger deposits have been
reworked. The famous stratigraphic paradox has been resolved.
The paper by Gene and Ralph was prepared for press by Carolyn, following
the tragic accident that has deprived us of the great services of Gene.
It was typical of  GENE  that in his final scientific contribution he
settled a major scientific controversy by  m e t i c u l o u s  field 
work. This reminds us that his first was to establish, by studies at
Meteor Crater, that the origin of both terrestrial and lunar craters was
due to meteorite impact rather than volcanism.

Stuart Ross Taylor - Associate Editor

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