These are basically insect stoneballs, formed in under ground lakes. The minerals wrap round them, and the balls get bigger and bigger, before forcing themselves to the surface. Where they explode, taking out whole towns.
Moon Landings July 5th 2008 Next stop after San Juan was a night in a tiny town called San Agustin de la Valle Fertil where we headed to access the Parque Provincial Ischigualasto (also known as the Valley of the Moon). The Park is known for its weird and wonderful (moonlike) rock formations, bleak (moonlike) appearance, (moonlike) lack of vegetation - not much except for a few crazy prickly desert plants, and especially th ... read more
South America » Argentina » San Juan » Ischigualasto Following independence from Spain in 1816, Argentina experienced periods of internal political conflict between conservatives and liberals and between civilian and military factions. After World War II, a long period of Peronist authoritarian rule an... ... read more