For most organisms on Earth, rocks are objects, not food. But for one oddball microbe, desert limestone seems to have been on ...

Gravel, on the other hand, is like a melting pot of a lot of different rock pieces, including limestone, basalt, and sandstone. Put simply, limestone is a type of rock that is formed by organisms ...

Chalk, limestone, shale ... some of the minerals in the sediment harden and form a kind of cement which sticks the grains of the rock together. Look through the slideshow to find out more about ...

Unusually small burrows, i.e., tiny tubes that run through the rock in a parallel arrangement from top to bottom, were discovered in marble and limestone ... of this kind in the Namibian desert ...

Unusually small burrows, i.e., tiny tubes that run through the rock in a parallel arrangement from top to bottom, were discovered in marble and limestone ... of this kind in the Namibian desert ...

The aqua blue waters lap the rock formations, and in some cases, blast water through crevices in the Anastasia limestone, which gave the preserve its name. My son regularly climbs barefoot on the ...

Mysterious micro-burrows in desert marble and limestone were probably made by microbes that lived millions of years ago. Exactly what kind of microbes bored into the rock remains unknown ...