“Bench, basalt, and bridge.”

The Great Basalt Debate

In the late 18th century, basalt was at the center of one of the most fierce scientific disputes in the history of geology: the battle between Neptunism and Vulcanism (also known as Plutonism).

• The Neptunist Theory: Led by German mineralogist Abraham Gottlob Werner, Neptunists believed that all rocks on Earth—including basalt—crystallized and precipitated out of a massive, primordial global ocean. They essentially categorized basalt as a sedimentary rock.
• The Vulcanist Theory: Opposing them were early geologists like James Hutton and Nicolas Desmarest, who correctly argued that basalt was formed from the cooling of magma or lava (an igneous rock).
  The Turning Point
  The debate was intensely fueled by the scientific study of spectacular columnar basalt formations, such as the Giant’s Causeway in Ireland and ancient flows in the Auvergne region of France.
  In the 1760s and 1770s, Nicolas Desmarest extensively mapped the basalt flows in France directly back to ancient, extinct volcanic craters. His physical evidence eventually proved the Vulcanists right, dispelling the ocean-precipitation theory and cementing basalt’s factual status as a volcanic rock.

WE&P by: EZorrillaMc&Co