Speaker
Description
$ICP-MS$ method has been used for analyses [1] of the elemental and isotope composition (64 elements) of bones of dinosaurs, South mammoths, prehistoric bear and archanthropus as well as the samples of surrounding soils; everything collected in different parts of Uzbekistan. A high concentration of uranium we detected in the bones of dinosaurs (122mg/kg), South mammoth (220mg/kg), prehistoric bear (24mg/kg) and archanthropus (1.5mg/kg) compared to surrounding soils (3.7-7.8 mg/kg) and standard bones (<0.01mg/kg) was established. The standart ratio $^{235}U/^{238}U = 0.007$ was detected for all samples. It was also observed that the $^{234}U/^{238}U$ ratio (Table) differ from $^{234}U/^{238}U = 5.4\times 10^{-5}$ secular equilibrium value. In this report the various mechanisms responsible for this difference are discussed.
Table. Data on uranium isotope ratios, detected by $ICP-MS$ with $1-SD$ errors in prehistoric bones, standard bone, and soils collected around these bones.
Sample $\hspace{0.5cm}$ $^{234}U/^{238}U\times 10^{-5}$ $\hspace{1cm}$ $^{235}U/^{238}U\times 10^{-3}$
MB1 $\hspace{1.4cm}$ 16.0±0.6 $\hspace{3cm}$ 7.4±0.2
SMB1 $\hspace{1.4cm}$ 11±1 $\hspace{3.4cm}$ 7.5±0.2
MB2 $\hspace{1.5cm}$ 9.5±0.2 $\hspace{3.1cm}$ 7.5±0.2
SMB2 $\hspace{1.3cm}$ 8.4±0.4 $\hspace{3.1cm}$ 7.6±0.2
BA $\hspace{1.8cm}$ 8.1±0.2 $\hspace{3cm}$ 7.2±0.2
BB $\hspace{1.8cm}$ 7.7±0.3 $\hspace{3cm}$ 7.4±0.2
DB $\hspace{1.8cm}$ 7.1±0.4 $\hspace{3cm}$ 7.2±0.2
SDB $\hspace{1.6cm}$ 7.2±0.3 $\hspace{3.1cm}$ 7.5±0.2
STB $\hspace{1.6cm}$ 7.2±0.5 $\hspace{3.1cm}$ 7.5±0.2
SSTB $\hspace{1.4cm}$ 10.6±0.3 $\hspace{3cm}$ 7.4±0.2
MB1& & SMB1 – South mammoth bone found in Angren and soil collected near this bone respectively; MB2& SMB2 - South mammoth bone found in Kashkadari and soil collected near this bone respectively; BA-arhantrope bone; BB – bone of bear from Selungur cave; DB& SDB – Dinosaur bone and soil collected near this bone respectively; STB & SSTB – standard bone and soil collected near the standard bone. The natural abundance ratio of the isotopes $^{235}U/^{238}U$ is $0.007257$, secular equilibrium ratio $^{234}U/^{238}U$ is $5.4\times 10^{-5}$ .
[1] I.N. Izosimov, et al., Czech Chemical Society Symposium Series, 20, 116(2022).
