Search results
Results From The WOW.Com Content Network
When a date is quoted, the reader should be aware that if it is an uncalibrated date (a term used for dates given in radiocarbon years) it may differ substantially from the best estimate of the actual calendar date, both because it uses the wrong value for the half-life of 14
The calculation of radiocarbon dates determines the age of an object containing organic material by using the properties of radiocarbon (also known as carbon-14), a radioactive isotope of carbon. Radiocarbon dating methods produce data based on the ratios of different carbon isotopes in a sample that must then be further manipulated in order to ...
Two different trends can be seen in the tree ring series. First, there is a long-term oscillation with a period of about 9,000 years, which causes radiocarbon dates to be older than true dates for the last 2,000 years and too young before that.
Radiocarbon dating is also simply called carbon-14 dating. ... For dates up to a few million years micas, tektites (glass fragments from volcanic eruptions), ...
Uncalibrated dates may be stated as "radiocarbon years ago", abbreviated " 14 C ya". [3] The term Before Present (BP) is established for reporting dates derived from radiocarbon analysis, where "present" is 1950. Uncalibrated dates are stated as "uncal BP", [4] and calibrated (corrected) dates as "cal BP". Used alone, the term BP is ambiguous.
Soil contains organic material, but because of contamination by humic acid of more recent origin, it is very difficult to get satisfactory radiocarbon dates. It is preferable to sieve the soil for fragments of organic origin, and date the fragments with methods that are tolerant of small sample sizes. [3]
The BP scale is sometimes used for dates established by means other than radiocarbon dating, such as stratigraphy. [5] [6] This usage differs from the recommendation by van der Plicht & Hogg, [7] followed by the Quaternary Science Reviews, [8] [9] both of which requested that publications should use the unit "a" (for "annum", Latin for "year") and reserve the term "BP" for radiocarbon estimations.
"The Effects of Possible Contamination on the Radiocarbon Dating of the Dead Sea Scrolls", Radiocarbon 43, 1 (2001) 127–132. Carmi, I., "Are the (super 14) C dates of the Dead Sea Scrolls affected by castor oil contamination?", Radiocarbon 44, 1 (2002) 213–216 (Response to Rasmussen et al. 2001.)