âº The coasts of the continents surrounding the Atlantic ocean could, if the continents were moved closer, fit together like a jigsaw puzzle. Reconstruction of previous position continents created with TimeTrek. âº Living animals in widely separated lands are similar.
The rock limestone is mostly made up of one of two types of mineral â either calcite or aragonite. Both of these are different crystal arrangements of the same chemical compound â calcium carbonate (CaCO 3).
Marble is made from limestone. At high temperatures and pressures, the crystals in the shells that formed limestone break down and. recrystallise. The rock that is produced is called marble. Marble. is much harder than limestone, and has a smooth even texture. Marble is a valuable rock for construction and decoration.