👉 Psammoliths are large, organic debris found in the crust of the Earth's outermost layer of rock. These rocks are composed primarily of calcium carbonate, and they can vary in size from millimeters to several meters. They form when the planet was young and were exposed to high temperatures and pressure during its formation process. The term "psammolithic" is a reference to this geological period of time, where the crust of the Earth was still very young and formed from the remnants of ancient
