Accurate carbon dating
New discoveries have filled in the gaps, and shown us in unimaginable detail the shape of the great ‘tree of life’.Darwin and his contemporaries could never have imagined the improvements in resolution of stratigraphy that have come since 1859, nor guessed what fossils were to be found in the southern continents, nor predicted the huge increase in the number of amateur and professional paleontologists worldwide.Many events can affect the levels of carbon-14 in the atmosphere, such as the burning of fossil fuel or the detonation of an atom bomb.In the new study using samples taken from Xingkai Lake near the Sino-Russian border in Heilongjiang province, the scientists used both radiocarbon dating and another method known as optically stimulated luminescence.For over 50 years, scientists and researchers have relied on carbon dating to find the exact age of organic matter.Prior to that, they had to depend on more rudimentary and imprecise methods, such as counting the number of rings on a cross-section of tree trunk..action_button.action_button:active.action_button:hover.action_button:focus.action_button:hover.action_button:focus .count.action_button:hover .count.action_button:focus .count:before.action_button:hover .count:before.u-margin-left--sm.u-flex.u-flex-auto.u-flex-none.bullet.
By measuring the remaining amount of carbon-14 in a sample, scientists could estimate the time of death up to 60,000 years ago.
"Many alternative methods to date objects are now available, but carbon dating is still the most popular because we have used it for a long time with such ease and comfort," said Liu, who was not involved in the study.
"But the method should be limited to young samples, and more efforts should be made to improve its accuracy," he added.
All these labors have not led to a single unexpected finding such as a human fossil from the time of the dinosaurs, or a Jurassic dinosaur in the same rocks as Silurian trilobites.
Paleontologists now apply sophisticated mathematical techniques to assess the relative quality of particular fossil successions, as well as the entire fossil record.