Among the cliffs and glades of western Kentucky, a mile-long trail cuts across a patch of prairie. A sandstone arch called Mantle Rock looms in a nearby hollow, where thick carpets of moss soften the ...

The deep oceans are far from flat. They feature ridges, trenches, seamounts, and valleys, creating a diverse and dramatic ...

Data gleaned from analyzing the isotopes in igneous zircon suggested that younger magma flowed into the existing continental crust, causing mantle rock to melt and hot magma to pool at the crust ...