Travel Reference
In-Depth Information
published its first description of these fossils, a massive tome describing 260
species all new to science. Not a single one of these species was known from
anywhere to the east, including Europe! The Cretaceous System (the large-
scale time unit defined by Sedgewick and others) could be recognized, hut
the Cretaceous stages (the smaller-scale units of d'Orbigny and others), all
based on ammonites from Europe, could not. These findings put an end to
D'Orbigny's dream that his stages would be recognizable and useful all over
the world. The Californian work of Gabb showed that only the most ap-
proximate sort of correlation could he found. More than a century later, this
situation had improved only slightly. Using tiny fossil skeletons of
fofaminiferans, a type of free-floating amoeba with a shell, one could roughly
recognize the European stages on the Pacific Coast. Many uncertainties re-
mained when a new generation of paleontologists re-examined the rocks and
fossils of California, Washington state, and western British Columbia in the
middle of the twentieth century.
Time after time
The pioneering European geologists had made two great discoveries that are
still useful today: (1) The most accurate way to understand the geometry of
various rock bodies on the earth's surface is to make a map of them, and
(2) the best way to disentangle the relative ages of various sedimentary rock
units is to collect and study their enclosed fossils. The scientific study of the
Sucia Island region required both.
The collections of fossils made by many paleontologists over almost a
century had yielded a good idea about Sucia Island's cast of ammonites and
their stratigraphic positions on the island. But the Sucia strata are but one
slice of the much thicker stratal layercake found in the Vancouver Island re-
gion. Where
(stratigraphically
, not geographically) in this 15,000-foot-thick
pile of sandstone, shale, and conglomerate does Sucia sit? How does its age
compate with that of the sedimentary rocks found on nearby islands, such as
Orcas and Waldron? How does Sucia compare in age with these and to with
the more distant islands sprinkled around it? Sedimentary rock made up the
