
1) Sedimentary rock
Found on
https://www.crosswordclues.com/clue/rhizolith

Rhizoliths are root systems that have been encased in mineral matter. Rhizoliths are created through processes of chemical weathering, decomposition, reprecipitation and cementation. Rhizoliths are formed through the transport of dissolved Ca2+ and HCO3- enhancing the CaCO3 precipitation in a diameter of up to several centimeters around the roots....
Found on
http://en.wikipedia.org/wiki/Rhizolith
No exact match found.