The Occurrence of Asphaltite and Thucholite in the Precambrian Bedrock of Sweden

The alteration of organic matter in response to ionising irradiation: Chemical trends and implications for extraterrestrial sample analysis

“…Boliden. Radioactive bitumen occurs in andalusite rock of the Palaeoproterozoic, in the Boliden Au-Cu-As deposit, Sweden (Welin, 1966; and references therein). Reported radioelement concentrations (% wt.)…”

“…Those values are comparable to those obtained here, with the exception of bitumen from Boliden. The carbon isotopic ratio of bitumen from Boliden was previously measured to be À29.2& (Welin, 1966). This was a single analysis of material apparently unrelated to that studied here.…”

Raman spectroscopy of irradiated organic matter

“…Radioactive bitumen occurs in andalusite rock of the Palaeoproterozoic, in the Boliden gold-copper-arsenic deposit, Sweden (Welin, 1966, and references therein). Reported radioelement concentrations are: 5.8% uranium and 0.82% thorium (averages of five samples, Aminoff, 1943); 10.2% uranium and 0.16% thorium (Grip and Ö dman, 1944) and 9.67% uranium (Eakin, 1989).…”

Reflected-light microscopy of uraniferous bitumens

“…Similarly, the absence of uraninite not associated with bitumen does not support the suggestion that pre-existing uraninite was the source of the uranium. Where uraniferous bitumens have formed by the dissolution/precipitation mechanism, free uraninite or pitchblende are found elsewhere in the deposits (Miller and Taylor, 1966;Welin, 1966).…”

“…T n E intimate association of uranium with organic matter has been known since the last century (see Dons, 1956, andWelin, 1966, for reviews). The close association arises both from the ability of mobile hydrocarbons to replace pre-existing uranium minerals (Dubinchuk et al, 1977) and the oxygen-bearing ligands in organic matter to form soluble U 6+ complexes (Nash et al, 1981).…”