From Cultures of Natural History edited by Jardine, Secord and Spary
From Cultures of Natural History edited by Jardine, Secord and Spary |
Enormously influential, Abraham Gottlob Werner left both a good and bad legacy to the science of geology. On the down side, he promoted the "Neptunian" view of the earth, claiming that all rocks had been deposited in a primordial ocean. This view, which had been in existence before Werner promoted it, was accepted almost without question and prevailed until overturned by James Hutton near the close of the 18th century. To his credit, however, Werner developed techniques for identifying minerals using human senses, drawing on a background in mining. Werner's practical classification system appealed to a broad audience interested in learning more about geology.
Werner also proposed new ways of thinking about geologic formations. Despite a keen understanding of rock minerology, Werner redefined "formation" to refer not to the chemical makeup of a rock, but to the timing of its development. He defined formations as bodies of rock formed in the same period, giving scientists a way of thinking about the rocks' histories.
In the 18th century, rocks were explained in terms of the biblical flood, and were classified into three categories that most people associated with the biblical flood: "primary" for ancient rocks without fossils (believed to precede the flood), "secondary" for rocks containing fossils (often attributed to the flood itself) and "tertiary" for sediments believed to have been deposited after the flood. Werner didn't overturn the commonly held belief in the biblical flood, but he did recognize a different group of rocks that didn't fit this classification: rocks with a few fossils that were younger than primary rocks but older than secondary rocks. He called these "transition" rocks. Geologists of succeeding generations classified these rocks into the geologic periods still accepted today.
For more information:
The Practical Geologist by Dougal Dixon
Cultures of Natural History edited by Jardine, Secord and Spary
Bursting the Limits of Time by Martin J.S. Rudwick
The Meaning of Fossils by Martin J.S. Rudwick
Charles Darwin, Geologist by Sandra Herbert
Fossil Revolution by Douglas Palmer
Narrative text and graphic design © by Michon Scott - Updated January 28, 2006