FOSSILS

FOSSILS The word ‘fossils’ comes from a latin word fossus which means ‘dug up’. Fossils are the remains or mars of plants and animals that lived a very long time ago. They are usually found in rocks and stone. Generally, fossils are made from the hard parts of plants and animals, such as bark, seed cases, bones and teeth. The totality of fossils, both discovered and undiscovered, and their placement in fossiliferous (fossil-containing) rock formations and sedimentary layers (strata) is known as the fossil record. Uses of fossils Serving science and industry To geologists fossils help solve problems about origins, age and relationships of sedimentary rock layers. To paleontologists they are a history of life, showing what previous organisms looked like and how they functioned and evolved. To geochemists, fossils are time capsules. Some fossils provide stable isotopes of oxygen, carbon and strontium, which provide insights into what past climates and environments were like, and how extinctions occur. Some rocks such as limestone are almost entirely made up of fossils. Limestone is a biogenic rock – it has formed from the skeletal remains of once-living creatures. Limestone is used to make cement, for building (such as Ōamaru stone), and is also crushed and applied to farmland as fertiliser. Fossil fuels Fossil fuels are natural resources such as coal, oil and natural gases containing hydrocarbons. These fuels are formed in the Earth over millions of years and produce carbon dioxide when burnt. Coal is used as a fossil fuel by providing worldwide electricity and heating. Oil is used as a fossil fuel to help create motor gasoline and diesel fuel. It is also used to make crayons, dish washing detergent, heating homes, fueling cars e.t.c. Natural gas is used as a fossil fuel to create medicine, propane paint fertilizers photo films, antifreeze e.t.c Underground exploration for oil, gas, coal or water makes use of microfossils. As they provide information on the age, origins and relationships of rock layers they provide geologists with clues as to where coal, oil or gas is likely to be found – usually porous rocks that were once coastal sands.