That’s a ripple mark left by water that used to sit on top of this before it was rock. This used to be sand and other sediment - that's why it is called sandstone - which is a type of ...

and especially in the manner of origin of diverse rock-types from a common stock or from a limited number of primitive ‘magmas’. The speculations of Be Beaumont, Bunsen, Durocher, and others ...

Rocks can experience squeezing, stretching, or pushing in different directions in response to stress. This response depends on the type of stress, the rate at which it is applied, the ...

They are nodule-like rocks typically found in volcanic regions, and specifically, those with rhyolite lavas. They look a bit ...