Have you ever heard of sand tufa or tufa towers? These unique erosion formations stand like giant cauliflower stalks on a lake bed. They are commonly found in the states of California, Arizona and Nevada.
Tufas are a fantastic example of what nature can do with a few basic elements. They grow exclusively underwater, and some grow to heights of over 30 feet. They become visible only when the water levels recede or when water bodies dry out over many years.
Tufa towers are columns of limestone which form in carbonate-rich saltwater lakes. When calcium-bearing freshwater springs meet the alkaline lake water, calcium and carbonate salts react to form the insoluble calcium carbonate (limestone).
Over centuries these deposits gradually grow into towering columns and strange cauliflower-shaped mounds. You could be forgiven for thinking that the images of these weird rock formations come from another planet.
[Image Source: @flickr]