From a Watery Origin by Wayne Pinkston Via Flickr: Website, Instagram, Facebook Tufas arising from their watery origins. These tufas are composed of calcium carbonate which precipitates out of the water from springs lying along the lake bed over millennia. Some are seen arising from the lake while others are now exposed on land after the shoreline has receded. Stacked image for the sky, long exposure for the foreground (3 minutes at ISO 1600).