geochron

geochron

[′jē·ə‚krän]
(geochemistry)
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The material was also dated for the purpose of the present investigation; the skeleton number 717-MN-RJ provided a 19th century chronology of 140 [+ or -] 30 BP (BETA-291714-AMS, [C.sub.13] corrected), and the skeleton number 718-MN-RJ provided an 18th century chronology of 210 [+ or -] 40 BP (GEOCHRON MA GX31824-AMS, C13 corrected).
Fortea undertook a first radiocarbon dating programme in 1993, sampling parietal black pigments from several figures for AMS [sup.14]C measurements in the LSCE -Gif-sur-Yvette, France--and after in 2001 for Geochron (Fortea, 2000/2001, 2002) (Fig.
Carbon-14 dating (C-13 corrected, Geochron Laboratories) was performed on two sediment samples (sample 9: reference GX-21287; sample 15: reference GX-21288) with abundant remains of shells, mainly Ostreidae.
The pointedly uncluttered installation featured eight works (all 2012) in video, sculpture, drawing, and sound, as well as a bit of sly architectural intervention, and it contained certain individual moments of interest: Untitled (Dog), a faithfully rendered Great Dane inflated to humorously Brobdingnagian proportions; Untitled (Sun), a modified geochron in which all political borders and points have been erased, leaving the day to pass its transit across a great undifferentiated terrestrial mass; an untitled, easily overlooked cut made into one of the gallery walls whose bottom edge was incongruously finished with a pale marble ledge.
Testing of Dicarb results from an archaeological site in north Alaska with cross-check samples analysed at other laboratories (Beta Analytic, Geochron, NSF-Arizona AMS) demonstrated that the Dicarb dates were significantly more recent than those produced at other laboratories with differences ranging from 350 to 1440 years.
Kemp's (2008) results included 11 stable isotope analyses on jackrabbit collagen by Geochron Labs in Cambridge.
The cultural origin of this finding was established based on ceramics, the morphology of the tombs, and dwellings by archaeologists from the ICANH and further tests on isotopes [[delta].sup.13]C, [[delta].sup.15]C, and [[delta].sup.15]N were made at Geochron Laboratories in Cambridge, Massachusetts.
A large Geochron clock hangs on the major wall, representing the movement of time in the world.
The radiocarbon specimens were processed at Geochron Laboratories in Cambridge, Massachusetts.
The data from a given suite are compared to the known values of potential mantle reservoir and crustal rocks, and to the "geochron", which is a line where all data from modern suites plot if their Pb isotopic compositions are unaffected by secondary processes.