The degree of contamination affects the magnitude of the inaccuracy in the carbon 14 dating results.In general, infinite-age contamination can make a sample considerably older while modern contamination can make the sample significantly younger than its true age.

When roots of plants penetrate wood, charcoal, soil, or bones, modern carbon is already introduced to them.

This occurrence can make the samples seem younger than their true age.

For example, bone samples can be contaminated by the presence of limestone or organic acids in the soil (like humic or fulvic acids) where the bones were found.

Another example of a natural contaminant is plant root penetration on wood, charcoal, or soil.

Animals and plants naturally incorporate both the C-12 and C-14 during their lifetimes.

When a creature dies, it ceases to consume more radiocarbon while the C-14 already in its body continues to decay back into nitrogen.The specific effect of the contaminant on radiocarbon dating results depends on the type of contaminant, the degree of contamination, and the relative ages of the sample and the contaminant.Limestone is of geological origin and would be much older than any archaeological sample; hence, inclusion of limestone during the carbon 14 dating would make the sample older than its true age.Learn more Materials such as sediments and soils typically undergo acid washes (no alkali) before radiocarbon dating.Learn More Materials such as shells and other materials where a date on the inorganic carbon (carbonate) is to be done typically undergo acid etching before pretreatment.Radio carbon dating is a technique of finding out the age of organic matters like fossils, wood, leather etc.