Sedimentary materials

Usage examples of sandstones.

Most of the rocks glimpsed were apparently Jurassic and Comanchian sandstones and Permian and Triassic schists, with now and then a glossy black outcropping suggesting a hard and slaty coal.

But to geologists and palaeontologists this land of sandstones and shales, piled up into the tablelands the Afrikaners called koppies, was one of the Earth's greatest storehouses: a thousand-mile slab of sedimentary rock that was the best record on Earth of land-animal evolution.

It sweeps away any fine-grained material, including, in time, the solid rock of sandstones and mudstones, but it can’t move the bigger material, like chunks of bone.

They are, effectively, vast deep holes in the ground with sandstones at the bottom from which water bubbles out of perennial springs.

The pre-Cambrian granites and beacon sandstones thus obtained confirmed our belief that this plateau was homogeneous, with the great bulk of the continent to the west, but somewhat different from the parts lying eastward below South America - which we then thought to form a separate and smaller continent divided from the larger one by a frozen junction of Ross and Weddell Seas, though Byrd has since disproved the hypothesis.

Often, sandstones will have a lenslike cross-section, pinching out at the edges.

The one sort are the sandstones of Settignano and Montisci, which being made into millstones, by virtue thereof flour is made.

They looked like layers of sedimentary rocks on Earth, sandstones or shales, laid down by ancient oceans, the myriad deaths of sea creatures.