The World Underfoot

The archives of the Academy of Natural Sciences of Drexel University hold one million items including as manuscripts, maps, letters, field journals, films and photographs. All of these items remain stored away and protected until pulled from a shelf by a researcher for study.

Or, until one celebrates an anniversary.

A map created by geologist William Smith in 1815 was recently pulled from its dark storage place and put on display in honor of its 200th birthday. It was the world’s first nationwide geological map, and it helped develop stratigraphy and biostratigraphy as we know it today.

What does that mean, exactly?

As Smith created his map, scientists were still debating the origin and structure of the earth. Smith’s brilliance came with a deeper understanding of the continuity of strata (stratigraphy) and the use of fossils within those layers to help with correlation (biostratigraphy). Both of these are foundational ideas in unraveling the history of the planet.

The map shows the distribution of the strata of England (from where Smith hailed), Wales and part of Scotland, and it was quite large — about five feet wide and nearly 10 feet high, a necessary size in order to meet Smith’s specification of five miles to the inch. Smith’s map wasn’t the first geological map, but it was the first to cover such a large area.

William Smith's map of England, Wales and part of Scotland, ca. 1815.

Six years earlier, American geologist William Maclure published the first geological map of part of the United States. In 1817, recognizing the importance of Smith’s map, Maclure, who is known as the “father of American geology,” purchased a copy of the map. In 1817, he donated it to the Academy of Natural Sciences, which was the same year he became its president (he held the post for the next 22 years).

Smith’s expertise came from years as a land surveyor and canal builder, mapping coal formations and assessing values for landowners, said Ted Daeschler, who is associate curator of vertebrate biology and vice president for systematic biology and the library at the Academy.

“Smith began to put evidence together about the geological formations that were encountered in coal mines and as they surveyed or dug canals,” said Daeschler. “He began to realize that geology was predictable; that you can map it and understand that a sequence in one area is often repeated in another area. That was all somewhat revolutionary to begin to understand the nature of the surface rocks.”

This was economically critical information, too, as one might imagine — if a sequence of strata that contained coal is also found elsewhere, there may very well be coal there, too, Daeschler says.

Today, the map’s value is in its history.

“This was the first detailed geological map, and maps like these are the foundation for doing earth science,” Daeschler explained. “To be able to express on a map the geology underfoot in a sensible and usable way was a huge step. Smith deserves credit as the guy who first got it right.”

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