James Hutton, 1785: The Theory of the EarthAn Earth “with no vestige of a beginning and no

prospect for an end…”

1) Earth History is Cyclical2) Earth Processes are Gradual3) The Earth is Infinitely Old4) The Interior of the Earth is Hot – the Earth is a

Fiery Machine5) Most Rocks are Igneous6) Basalt is an Igneous Rock

William Smith and George Cuvier - 1790’s

Smith: British Mining Engineer, Economic geologist.

Cuvier – Europe’s greatest anatomist (Swiss), studied functional morphology and extinction.

1) Once a species disappears it never again reappears.

2) No two species are identical.

These observations led to the following two principles:

1) The Law of faunal Succession – In the geologic record, fossil faunas succeed on another in an orderly and determinable fashion. Therefore, rocks of different ages have different fossil faunas.

2) The Principle of Fossil Correlation – Similar assemblages of fossils are similar ages, and thus the rocks that contain them are of similar ages.

Napoleon’sprofile

FOSSIL SUCCESSION

Fossil Correlation

Smith’s Geologic Map Modern Geologic Map

Based on studies of fossil elephants & giant sloths, Cuvier recognized that organisms have become extinct. This was highly controversial!

MassExtinctions

Cuvier noted that Earth upheavals (like mountain building events) were often accompanied by mass extinctions. Thus, the extinction of millions of organisms by violent Earth changes became known as Catastrophism. It was based on direct observation of the fossil record.

•Earth history was beset by violent upheavals that periodically wiped out nearly all organisms.•God then created a new fauna to replace the extinct one.•All this happened within Buffon’s age of 75,000 years. Buffon claimed, “ A year is to God as a thousand years is to man”.

The History of Life

In the 1820’s London begins to replace Paris as the center of geological research. The response to Catastrophism came from another gentleman Scotsman named Charles Lyell

Lyell was an Oxford student of a famous geologist/clergyman, the Reverend William Buckland (1784-1856), Dean of Westminster

William Buckland “The gentleman geologist”

Evidence for Buckland’s Diluvial Theory:1) Fossils of extinct species of hyenas are preserved

in ancient cave deposits. A product of flooded hyenadens in caves.

2) Earth’s last convulsion and extinction wasUniversal and caused by Noah’s Flood.

These deposits are generally confined to the northern parts Of the northern hemisphere. What caused them?

MolluscBorings

Temple of Serapis, near Naples, Italy

Lyell’s Uniformity: An idealized cross section of the Earth showing ancient and modern rocks being formed by the same processes.

Lyell’s Uniformitarianism

A) Methodological - Basis of Science1) Uniformity of Law2) Uniformity of Process – Actualism

B) Substantiative – Testable by Observation3) Uniformity of Rate (Gradualism)4) Uniformity of Condition (non Progressionism)

Professor Ichthyosaurus, at some future time after his triumphant return, lecturing to his students on the fossil skull of a peculiar Quaternary mammal.By Henry de la Beche, from Buckland, 1890.

"huge Iguanodon might reappear in the woods, and the ichthyosaurs in the sea,while pterodactyle might flit again through umbrageous groves of tree ferns.“

Charles Lyell, 1833

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Lyell Subdivided a major GeologicPeriod based on mollusc faunas

Succession of Rocks and faunasdemonstrated antiquity of Earth