GEOSITE
Phoenix Boulder (Bloque Fénix)
What is an erratic boulder? Who placed this massive rock here, and where did it come from?
The Phoenix Boulder is located approximately 17 kilometers south of the city of Chile Chico. As you approach this unique rock, you’ll notice that it’s far too large to have been carried by the river—and it’s also the only one in the area with its particular mineral composition.
These large boulders, found lying on plains with no obvious connection to nearby rock formations, were named “erratic blocks” by 19th-century geologists.
To better understand their origin: erratics are formed when a glacier or ice sheet moves across the landscape, eroding the underlying bedrock. The ice carries rocks, transports them over distances, and eventually deposits them when the glacier recedes. In this way, the Fénix Boulder tells the story of an ancient glacier that once existed in this area.
