Travel Reference
In-Depth Information
National Science Foundation to bring these plans to fruition. On the Cana-
dian expedition, it was Joe's turn to fly.
Baja British Columbia
We arrived on Hornby Island in early summer of 1995: Joe Kirschvink, Jose
Hurtado (a student assistant from Cal Tech), and me. We walked the beach
at the lowest of tides, the sun glancing off an occasional ammonite shell still
held tightly in the sediment. The ammonites, it turned out, gave us our best
hope of finally getting a real paleomagnetic position of these ancient sedi-
ments. The shells and the shapes of the fossils were our clue. Temperature is
the key to paleomagnetic analyses; if the sediments were heated too much,
they lost their magnetic signal. But our ammonite shells also reacted to high
temperature: Their pearly shells retained luster only in the absence of heat.
Any regional heating would recrystallize these shells to a dull tan or even
black. Because of the pristine nature of the ammonites from Hornby and
from a few other islands of the Vancouver Island region, we were confident
that a reliable paleomagnetic signal could be found. The key to success this
time on Hornby would be avoiding rocks that appeared to be oxidized in any
way or did not have a fresh surface. Joe's solution was to excavate all surface
rock deeply away before drilling, to ensure fresh rock.
For several days the three of us worked in exquisite weather, camping
nearby and sampling island cuisine after work. With more than 60 cores ob-
tained, we moved north to one of the largest and most obscure of the islands
in this region, a place called Texada Island. Here too we sampled the strata,
this time with much more difficulty, for the timber companies had devas-
tated this island. Whereas on Hornby the fossiliferous rock is exposed on a
seacoast, on Texada the sampling locality was an overgrown creek that years
ago had been clear-cut. The timber company that did the cutting on this
creek never cleaned up the snags, and the creek was an overgrown mass of
felled dead wood and colonizing brambles. Our prime locality could be
reached only by crawling half a mile over the snags carrying our heavy gear,
and it was relief when we finally finished this work without anyone breaking
