CONNOR: Good thinking! I read a bit about limestone on the bus journey. Limestone is a sedimentary rock created by layers of skeletons and shells of sea creatures found in ancient, warm ...

Limestone, made from calcium carbonate, takes millions of years to form. These sedimentary rocks are born from the decay and fossilization of marine organisms — think coral and clams.

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

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 these desert regions. In the desert ...