Travel Reference
In-Depth Information
to die-hard critics of this particular terrane drift—two men who do not ac-
cept the validity of the Baja British Columbia hypothesis.
Inclination shallowing is a phenomenon wherein compaction of sed-
iment, caused hy the slow but inexorable accumulation of sedimentary
beds one atop another, eventually flattens underlying sediment to the
point where the magnetic signal "shallows," or gives evidence of a lower
latitude than was originally present in a bed. For example, some sedimen-
tary bed might have been deposited in latitude 45 north. However, the
gradual squashing of this sediment over time may slightly flatten out the
small magnetite grains such that the paleomagnetic signal measured might
be 34 or 35 degrees. These two reviewers had dismissed every Mesozoic pa-
leomagnetic of tropical latitudes in now-northerly localities as either due
to inclination shallowing or coming from studies where the original hori-
zontal attitude of the rocks could not be ascertained. Our paper was re-
jected.
If I was ctestfallen, Joe was outraged. Our study was
not
contaminated by
compaction shallowing, he announced to me over the phone soon after our
rejection, for a simple reason: The ammonites, so abundant in the sediments
from Hornby and Texada, were not compressed. If compaction shallowing
were taking place, it would affect not only the magnetite hut the fossils as
well: The fossils would he flattened. Clearly they were not, so inclination
shallowing could not have taken place.
We communicated this to the editors in an appeal, and after more re-
views the paper was accepted. Published on September 12, 1997, it pte-
sented a data set that gave more credibility to those who maintain that the
"suspect terrane" known as Baja British Columbia is less suspect than most.
Who—or what—was watching, so many millions of years ago, when
the entire block of what is now British Columbia crashed into North
America to be welded in place? Magnetometers ate the time machines that
have revealed to us this surprising event in earth history, when ancient Mex-
ico cast off its moorings and sailed north. Canada is a far richer place as a re-
sult. But will the Mexican government, so keen on repatriation, demand its
territory hack?
