Spanish Conquest May Have Altered Peru's Shoreline

Spanish Conquest May Have Altered Peru's Shoreline
19 May 2014 3:00 pm

In 1532, Francisco Pizarro led an expedition of battle-hardened Spanish soldiers on a fateful journey, from the desert coast of northern Peru to the highland Inca city of Cajamarca. A civil war had just ended in the Inca Empire, and Pizarro and a party of fewer than 200 men marched eastward to capitalize on the turmoil.

The ensuing Spanish conquest of the Inca had a profound effect on the region’s indigenous people, but a new paper published today in the Proceedings of the National Academy of Sciences reveals that it also had an unexpected impact on the land itself. Before the Spaniards arrived, inhabitants of the arid northern Peruvian coast clad massive sand dune–like ridges with an accidental form of “armor”: millions of discarded mollusk shells, which protected the ridges from erosion for nearly 4700 years and produced a vast corrugated landscape that “is visible from space,” says archaeologist Dan Sandweiss of the University of Maine, Orono, one of the paper’s authors.

This incidental landscape protection came to a swift end, however, after diseases brought by Spanish colonists decimated the local population and after colonial officials resettled the survivors inland. “There were very few [indigenous] people living along the coast then,” says lead author and geologist Daniel Belknap of the University of Maine, and without humans to create the protective covering, newly formed beach ridges simply eroded and vanished.

Belknap and Sandweiss began examining the surviving ridges in 1997, selecting a set of nine that extend 21 kilometers in length northwest of the mouth of the Chira River. A previous researcher, archaeologist James Richardson III of the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania, had noted an abundance of shells, pottery sherds, and fire pits covering these beach ridges, so the University of Maine researchers decided to study the sand formations and their origins.

More:
http://news.sciencemag.org/archaeology/2014/05/spanish-conquest-may-have-altered-perus-shoreline