Geologic Time

  • William W. Hay


In the seventeenth century the age of the Earth, based on biblical sources, was estimated to be 6,000 years. Looking at the rock record on the coast, Scottish geologist James Hutton realized that the Earth was very much older; there was literally an abyss of time. The geologic record in the Paris Basin suggested that there had been not one, but a series of ‘Creations’ each ended by a catastrophe. In the early nineteenth century Charles Lyell realized that the same geologic processes operating today had been at work in the past, and that geologic change was imperceptibly slow. This concept became known as ‘Uniformitarianism.’ The sequence of rocks and a relative geologic time scale based on superposition was worked out during the nineteenth century. Two major discoveries indicated that conditions in the past had been very different from those of today: the Ice Age and warm Polar Regions. Americans championed the idea of permanence of continents and ocean basins; Europeans suggested the Earth’s crust was mobile, and even that the continents had drifted apart with time. It was recognized that life on the planet had experienced a number of extinction events.


Ocean Basin Planktonic Foraminifera Geologic Time Scale Dense Rock Jura Mountain 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  1. 1.University of Colorado at BoulderEstes ParkUSA

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