The Heretic’s Flood - The Rocks Don't Lie - page 169

are now all catastrophists.” 2 It took a changing of the generational guard for geologists to
accept the heretic's flood.
In the summer of 1976, just before his ninety-fourth birthday, NASA scientists invoked
Bretz's careful fieldwork on understanding features diagnostic of catastrophic flooding to
explain streamlined hillslopes and giant channels in images returned by the Viking space-
craft orbiting Mars. Half a century after government scientists gathered to denounce his
radical theory of erosion by catastrophic flooding, NASA was hailing his studies of the
channeled scablands as the key to understanding enigmatic Martian landforms.
In 1979, the Geological Society of America awarded Bretz its highest honor, the Penrose
Medal. He was ninety-seven years old and is reported to have jokingly complained to his
son, “All my enemies are dead, I have no one to gloat over.” In hindsight, he described
his work as a struggle against the dominance of uniformitarian thinking that prejudiced his
colleagues against the idea of a great flood:
Was not this debacle that had been deduced from the Channeled Scabland simply a return, a retreat to catastroph-
ism, to the dark ages of geology? It could not, it must not be tolerated… . They demanded, in effect, a return to
sanity and Uniformitarianism. 3
Later fieldwork by others revealed evidence for many floods, each of which left a single
thin layer in thick stacks of backwater sediments. The ice dam had failed over and over
again. When an advancing glacier dams a river, it can prove stable until the water backs up
deep enough to float the ice, catastrophically undermining the dam. Once the lake drains,
the ice can readvance, repeating the whole process again and again until the glacier finally
retreats. The ice dam blocking Lake Missoula's only outlet had become a virtual flood ma-
chine.
Calculations accounting for the estimated rate of flow into the lake indicated that it took
three to seven decades to fill, the same time interval between lake-draining floods revealed
by the number of annual sediment layers in the lake bottom sediments. Downstream, care-
ful stratigraphic analyses showed that each layer of flood-deposited sediment represented
a separate event with velocities exceeding twenty feet per second. Radiocarbon dating of
organic matter deposited in the flood sediments revealed there were as many as 100 separ-