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The EarthWord: The Mother Lode

Definition:

• The Mother Lode is a principal vein of a valuable mineral commodity, particularly gold or silver.

Etymology:

• Lode is the Middle English spelling for the word "load."

Use/Significance in the Earth Science Community:

• It's also the name given to a region of the western Sierra Nevada in California. Its extensive gold deposits, and their accessibility, led to the Gold Rush of 1849.

USGS Use:

• In a survey of the region's mining activity in 1929 by USGS scientist Adolph Knopf, he noted that the name was misattributed. Folks mistakenly believed "that a quartz vein extends continuously from one end of the belt to the other—the Mother Lode." The vein isn't actually continuous, but the name stuck.
• According to Knopf, the total output of the Mother Lode in 1924 was $240 million. (That's over $3.3 billion today, adjusted for inflation)

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