Page 41 - The Restless Earth Fossils

40 Fossils

Then, some process of uplift pushed the rocks to a vertical posi-
tion. We know today that mountains rise roughly at the same
speed that fingernails grow. Erosion must have created the jum-
bled rocks between the two-layered sequences. That, too, took a
lot of time. Then, the sea either advanced or the land sank (sub-
sided) and the long process of creating many new layers began.
The sea retreated again (or the land rose) and more erosion took
place to form the soils of Washington.
Before Hutton’s time, the history of our planet consisted of
“a short tale of uninterrupted erosion,” in the words of the late
paleontologist Stephen Jay Gould. Hutton realized that angular
unconformities showed clearly that Earth’s history involved long
periods of alternating episodes of deposition, uplift, and erosion.
The uplift part of the process implied that powerful regenerative
forces created mountains from old seafloors that, in turn, eroded
away to form new, layered deposits on some fresh ocean basin.
Hutton thought this process to be never-ending. He saw “no
vestige of a beginning—no prospect of an end.” Later scientists
would find this phrase a bit imprecise, but Hutton had produced
a major geological insight from a striking image of Earth’s forces
frozen in time.

the present as the Key to the past:

uniForMitarianisM
Charles Lyell (1797–1875) was born the year Hutton died, but
geologists usually link his name and Hutton’s because he wrote
an influential book, The Principles of Geology (published in three
volumes from 1830 to 1833), promoting the essence of Hutton’s
ideas. Lyell emphasized the concept that forces in the past must
have acted essentially as they do today. This concept acquired
the name Uniformitarianism. Lyell denied the existence of
biblical-style floods like those proposed by Cuvier, yet the fossil
record does show that entire ecologies changed abruptly on rare
occasions. Geologists have since learned that Earth has endured
volcanic eruptions, weather changes, ocean currents, and even
hits by space rocks (meteorites) far more severe than anything

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