Reliability of radiocarbon dating
It is assumed that we are dealing with a closed system—no loss of either parent or daughter elements has occurred since the study material formed.No scientist can guarantee that any sample can be considered a closed system unless it was isolated from its environment when it was formed.Specimens would then look much older than they actually are.d) Even if the rate of decay is constant, without knowledge of the exact ratio of carbon-12 to carbon-14in the initial sample, the dating technique is subject to question.You can help Amazing Discoveries reduce costs by upgrading or replacing your internet browser with one of the options below.We thank you in advance for partnering with us in this small but significant way. All methods of radioactive dating rely on three assumptions that may not necessarily be true: It is assumed that the rate of decay has remained constant over time.This assumption is backed by numerous scientific studies and is relatively sound.
Grenda, Jeffrey Homburg, Manuel Palacios-Fest, Steven Shelley, Angela Keller and Davis Maxwell Spatial and Temporal Distributions of Archaeological Heated-Rock Cooking Structures in the Transverse Mountain Ranges: Proposed Markers of Land-Use Shifts since the Early Holocene [SCA Proceedings - PDF].
Some scientists argue that the magnetic field of the earth has declined over time.
c) Atmospheric carbon forms just 0.0005% of the current carbon reservoir—99.66% of the earth's carbon exists in limestone, 0.31% in oil and gas, and 0.02% in coal.
Many examples from literature show that the zero-reset assumption is not always valid.
Volcanic ejecta of Mount Rangitoto (Auckland, New Zealand) was found to have a potassium-40 age of 485,000 years, yet trees buried within the volcanic material were dated with the carbon-14 method to be less than 300 years old.