Collie and Black Diamond Lake
The Pinnacles are located in a desert of the Nambung national park. These amazing limestone structures were formed approximately 30,000 years ago after the sea receded and left deposits of sea shells. Over time, coastal winds removed the surrounding sand, leaving the pillars exposed to the elements. The Pinnacles range in height and dimension – some stand as high as 3.5mare a major natural attraction for the south west and have a mysterious air about them, as if they were once living, and somehow frozen in time.
There is an air of mystery that cannot be denied when visiting this unique and eerie landscape. How they came into existence is widely debated; there are three main theories:
The first states they were formed from remains of Tamala Limestone deposits after extesive weathering, forming solution pipes which progressively enlarged over time. Some became more errorded than others, while some aremore solid in structure, filled with microbialites and sand.
The second theory states they were formed through the preservation of tree casts, whose roots became groundwater conduits, resulting in the creation of calcitrate. Erosion of the aeolianite then exposed the their skeletal calcrete pillars.
The third proposal suggests that plant life and shells were responsible for the creation of the Pinnacles, based on the mechanism that formed smaller “root casts” in other parts of the world. As water was drawn through the soil to the roots, excessive nutrients and other dissolved minerals flowed toward the root accumulating the rich nutrients at the surface of the root, causing large amounts of calcium (from marine shells) to the roots. The flow of water drove the excessive calcium deposits to the root surface.