Travel Reference
In-Depth Information
but had lived in the Mesozoic Era. How many years ago was
that,
I asked.
Hundreds of millions, he somewhat uncertainly replied. "But how do you
know? Have these rocks ever been put in some machine that tells theit age?"
Gone now was his confidence, and 1 knew he was on shaky scientific ground.
He lost patience with me, and my father and I soon left.
1 had discovered many small truths that day and one much larger one:
Divining the age of a rock can be very difficult. Years later, I would be asked
the same question innumerable times and, like the rockhound of my youth,
would never be able to give a short, satisfactory explanation. There is no
short explanation. There is no magic box that, when placed over some dusty
relict of our planet's tumultuous and seemingly ageless past, displays some
shining number. It is not that we do not have machines that give ages. It is
just that such machines work only on a very small suite of rock types—and
even then only on an smaller subset of those rocks that have lain relatively
undisturbed for great swaths of time. And tranquility is a very tare thing on
this planet's everywhere-disturbed surface.
Chance and time
Childhood fossils are usually left behind on yellowing shelves. For some of
us, however, they are never left behind. I could never put them away. They
were transfigured from curio to curiosity.
In 1971 I became a graduate student in paleontology. I wanted to study
fossil whales, but a chance event soon steered me toward a much older past,
the Mesozoic-aged life and times of ancient Sucia Island. Much of my school
work in that first year involved the study of stratigraphy (the geological dis-
cipline concerned with ancient time) and anatomy. But I learned as much
from constant scuba diving as I did from classes at the university. I learned
about the communities of organisms living in Puget Sound, who ate whom,
and how these communities of invertebrates are distributed in space and
time. I watched as sedimentary beds formed under the sea. I witnessed the
slow burial of dead shells and bones, whose long journey toward fossildom
was just beginning. Every dive was a new exploration, and with every dive I
