A Little Big History of Iberian Gold

We present a “little big history” of the gold that either was mined in the Iberian Peninsula, or was brought there from deposits located elsewhere, by trade or by conquest.  During Roman times, gold was extracted from the Peninsula itself.  In the Middle Ages, gold was brought across the Sahara from very rich near-surface occurrences in West Africa.  After the discovery of the New World, Colombia was the most important source of gold entering the Peninsula.  Each of these gold-bearing regions has had a different geological history, and in each one, gold was concentrated by a variety of geological processes.  The West African gold dates back to fairly early in Earth history, about 2 billion years ago, and resulted from closure of an ancient ocean basin.  The Iberian gold is related to the continental collision that produced the Appalachians and their Variscan continuation in Europe, while assembling the Pangea supercontinent.  The Colombian gold is associated with the subduction under South America of the Pacific Ocean crust that has produced the Andes.  For each of the three regions we present a database of historical and active gold mining areas, and we summarize this information in maps.  The ways in which Earth concentrates gold are the subject of much geological research, and we give a brief introduction to this remarkable topic, hoping that big historians will go beyond Carl Sagan’s statement that “We’re made of star-stuff,” and will recognize that “We’re made of star-stuff, concentrated by Earth.”