Numerical ages estimate the date of a geological event and can sometimes reveal quite precisely when a fossil species existed in time. Third, magnetism in rocks can be used to estimate the age of ...

Numerical ages estimate the date of a geological event and can sometimes reveal quite precisely when a fossil species existed in time. Third, magnetism in rocks can be used to estimate the age of ...

The characteristics of the rocks that hold fossils can be as informative as the fossils themselves. There are three main types of rock: igneous rock, metamorphic rock, and sedimentary rock. Almost all ...

There are over 5,000 known types of minerals. Just a few minerals make up most of the rocks we see, though: feldspars, amphiboles, quartz, olivine, garnet, micas, calcite, and pyroxenes.