There are three main types of rock: igneous rock, metamorphic rock, and sedimentary rock. Almost all fossils are preserved in sedimentary rock. Organisms that live in topographically low places (such ...

The basalt which makes up the Giant’s causeway is an igneous rock. Sedimentary rocks are formed by small rock pieces which are transported by rivers and laid down in layers. Chalk is a ...

I am a chemical sedimentologist: I study how and why chemical sediments form and lithify, with the goal of better understanding how chemical sedimentary rocks (e.g., carbonates, chert, iron formations ...

The weight of each new layer helped compress the ones below, eventually forming sedimentary rock over millions of years. Some 65 million years ago, molten rock from deep beneath the earth’s ...

What Was Happening on Earth at This Time The Precambrian is the earliest of the geologic ages, which are marked by different layers of sedimentary rock. Laid down over millions of years ...