Direct dating of fossils
Absolute dating is the process of determining an age on a specified chronology in archaeology and geology.
(2011) claim to provide the first successful direct dating of fossil bones and to establish the presence of Paleocene dinosaurs. ignore previously published work that directly questions their stratigraphic interpretations (Lucas et al., 2009), and fail to provide sufficient descriptions of instrumental, geochronological, and statistical treatments of the data to allow evaluation of the potentially complex diagenetic and recrystallization history of bone.
Every so often, a curious thing happens to the Earth’s magnetic field.
We don’t really know why it happens, or even when it is likely to happen next, but every several hundred thousand years or so, the Earth’s magnetic field reverses. We know this, because when rocks are formed, they are indelibly marked with the normal or reverse polarity of their birth time, or chron.
Vertebrate fossils have been important for relative dating of terrestrial rocks for decades, but direct dating of these fossils has heretofore been unsuccessful.
In this study we employ recent advances in laser ablation in situ U-Pb dating techniques to directly date two dinosaur fossils from the San Juan Basin of northwestern New Mexico and southwestern Colorado, United States.