Reinvestigation of the decay of the long-lived odd-odd 176Lu nucleus

Geochemical test for branching decay of 176Lu

“…Summary of published values of 176 Lu determined during last 25 yr using ␥-counting (black diamonds), and age comparison against U-Pb on meteorites (gray squares) and on terrestrial rocks (white circles). The sources of data: ␥-counting- Sguigna et al (1982); Sato et al (1983); Gehrke et al (1990); Dalmasso et al (1992), Nir-el and Lavi (1998), Grinyer et al (2003), Nir-El and Haquin (2003); meteorite age comparisons- Patchett and Tatsumoto (1980), BlichertToft et al (2002), Bizzarro et al (2003)a; terrestrial rock age comparisons- Scherer et al (2001); Söderlund et al (2004). Since various isochron regression methods were used in the age comparison 176 Lu determinations, we have recalculated all Lu-Hf isochrons using Isoplot Ex 2.49 (Ludwig, 2001) program to assure compatibility of results.…”

γ-ray irradiation in the early Solar System and the conundrum of the 176Lu decay constant

“…The half-life of the decay of 176 Lu to 176 Hf (Norman, 1980;Sguigna et al, 1982;Sato et al, 1983;Gehrke et al, 1990;Dalmasso et al, 1992;NirEl and Lavi, 1998;Grinyer et al, 2003), as is true for other nuclides decaying by b-emission, such as 87 Rb and 187 Re, is notoriously difficult to measure directly using standard counting techniques. Typically, physical measurements provide precise but inconsistent values (Fig.…”

Hf–Nd isotope evidence for a transient dynamic regime in the early terrestrial mantle

“…The relatively small fraction of surface terrestrial heat¯ow accounted for by the heat production of radioactive elements in the crust and the upper mantle requires that substantial amounts of U, Th and K be 10 . In light of recent work 33,34 , the decay constant of 176 Lu has been revised and we now use a value of 1.876 10 -11 yr -1 throughout. An age of 3.80 6 0.05 Gyr is assumed for the Isua samples.…”