stratified rock

Geologists use radiometric dating of other elements with much longer half lives than Carbon-14 to estimate the ages of these stratified rock layers.

Carnegie’s steel, like almost all the steel ever produced in the world, was made with ore from Precambrian iron formations—stratified rock sequences, blood red and dull gray, that are typically mined in giant open pits.

Carnegie’s steel, like almost all the steel ever produced in the world, was made with ore from Precambrian iron formations—stratified rock sequences, blood red and dull gray, that are typically mined in giant open pits.

From there, the route hugged the shoreline, and I couldn’t help but imagine Mr. Muir as a boy, skipping over the acres of stratified rock to, as he wrote, “gaze and wonder at the shells and seaweeds, eels and crabs in the pools.”

At the upper edge of the hill was an outcrop of stratified rock.