Introduction: Understanding Igneous and Metamorphic Rocks

Igneous and metamorphic rocks are two major types of rocks found on Earth’s surface. Igneous rocks are formed by the cooling and solidification of molten magma or lava, while metamorphic rocks are formed by the alteration of existing rocks due to heat, pressure, and chemical reactions. These two types of rocks play a significant role in the geological history of the Earth and provide valuable information about the processes that have shaped our planet. One notable difference between igneous/metamorphic rocks and sedimentary rocks is the absence of fossils in the former. In this article, we will explore the reasons why fossils are not found in igneous and metamorphic rocks.

Fossil Formation and Preservation Processes

Before understanding why fossils are not found in igneous and metamorphic rocks, it is essential to understand how fossils are formed and preserved. Fossils are the remains or traces of ancient organisms that have been preserved in the Earth’s crust. The fossilization process involves the rapid burial of an organism in sediment, which can protect the remains from decay, scavengers, and other destructive forces. Over time, the sediment hardens and turns into sedimentary rock, preserving the fossil within its layers. Fossils can also be preserved in other ways, such as petrification, where minerals replace the organic material of the organism, or by being trapped in amber or tar.