Radiocarbon measurements, comparison

Trumbore, S. E. (1993). Comparison of carbon dynamics in tropical and temperate soils using radiocarbon measurements. Global Biogeochem. Cycles 7(2), 275-290. 

Unlike some dating techniques (such as uranium-series dating on speleothems or corals), radiocarbon is not an absolute dating technique, but relies on the comparison of radiocarbon measurements on samples to those made on samples of known age (a process called calibration). In order to understand the limitations and... 

The Holocene spans the past 11,500 years. Much of the Holocene time scale is obtained from Greenland and Antarctic ice-core data, from stratigraphic pollen records, and other records of floral, faunal, and landscape changes. Records younger then 45,000 years are also within the range of radiocarbon dating. The recent Holocene is the historic period when some written records are available and finally the past century or so, the contemporary period, where directly measured climatic data are available for comparison. 

Net production has been measured directly by radiocarbon incubation experiments, whereby water samples are spiked with radiocarbon-labeled bicarbonate, and the net rate of transfer of the radioisotope into organic matter phases determined by comparison of light versus dark incubations. Global maps of net productivity have been constructed on the basis of such measurements, and current... 

Fig. 7.1 Comparison between empirical evidence and theoretical models for the spread of agriculture in Europe [137]. The points are the data already analyzed in [13], distances being measured as great circle routes from Jericho (the presumed center of diffusion). Dates are conventiontil radiocarbon ages in years Before Present (B.P.). The full line is the regression by Ammerman tmd CavaUi-Sfotza (correlation coefficient 0.89) [13], The other three lines are least-square fits with slopes calculated from the classictil wave-of-advtmce model with D a /T dashed-dotted line), D dashed line) given by (7.5), and from the RT model with D as in (7.5) dotted line). Here T = 25 yr, r = 0.03 yr, and a /T = 1700 km /generation. Reprinted with permission from [137], Copyright 1999 by the American Physical Society...

Third International Radiocarbon Intercomparison (TIRI) standard wood samples (5,6,8) and four different archaeological charcoal samples (2,3J8) for comparison with dates previously determined at other laboratories using standard combustion methods. These measurements were utilized to demonstrate the viability of the plasma extraction technique for dating rock paintings from around the world with charcoal and inorganic pigments. 

This model estimate is supported by a comparison of radiocarbon monoxide ( CO) in low-latitude clean Southern Hemispheric air with that over the northern Indian Ocean, as measured from samples taken from the RW Brown. The clean air samples south of the ITCZ contained on average 55 parts per billion by volume (ppbv) of CO and 6.2 molecules of CO/cm whereas north of the ITCZ, this was 155 ppbv and 9.7 molecules/cm [26]. The CO difference between these air masses must be of biogenic origin, i.e., mainly biomass burning, because fossil fuels are radiocarbon-depleted. Previous analysis has shown that biomass burning adds 0.038 molecules of " CO/cm per ppbv of CO [26]. If we assume further that... 

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