Rhizoliths - Rootstone

Root casts (also called rhizoliths) are formed when roots, either alive or decaying, interact chemically with the soil around them. Technically they are trace fossils as they are the accretion of the soil surrounding the root, rather than preservation of the root material itself. A tiny hole in cross section is evidence of the location of the original root.          

What sets these Austin County root casts apart is the detail of the preservation, in many cases evidence of tiny rootlets or branching roots can be seen. Each piece is unique and is a record of the growth of the root either horizontally or vertically through the Pleistocene era soil.      

The calcareous cement make these typically fragile forms remarkably durable. Additionally, these roots were growing in a point bar environment so the beautiful crossbedding and layering of the original sand has been preserved and give the casts their appeal to collectors.