Early-diagenetic REE-phosphate minerals are widespread, although minor (<0.005-0.14wt percent), constituents of Archaean to Cretaceous sandstones from Australian sedimentary basins.Authi enic florencite ((REE)A13 (Po4) (OH) 6), crandallite (CaAL) (PO4)2 ( 8 H)6), and gorceixite (BaA13 (P04)2 (OH) 6) occur as clusters of minute crystals (<0.1-10 (mm in width) within pockets of clay matrix lining detrital quartz surfaces and less common1 within altered mica and feldspar grains.Rare florencite crystals Form along the surface of detrital monazite grains, and in one locality, crandallite and gorceixite crystals line cavities left after grain dissolution.The aluminophosphate minerals commonly display corn ositional zoning, with P major cation interchange between REE, Sr2+, Ca +, and Ba2+, and minor anion interchange between PO:, SO:, and CO;.Xenotime (YP04), which contains minor amounts of Th, U, and REE, forms pyramidal, dentate overgrowths (< 1-20 (mm) on detrital zircon grains and locally part1 surrounds detrital quartz surfaces.Authigenic apatite is generally f ess abundant than diagenetic aluminophosphate and occurs as Birger Rasmussen-Early-diagenetic REE-phosphate minerals ably considerably greater than previous estimates and, for the oceanic P cycle to remain in a steady state, implies a decrease in the output of other sinks or an increase in the P input.A higher output of reactive P will also reduce estimates of the oceanic residence time of P (from this study, between 11-2Oka).As P iscrucial for sustaining marine life, such changes in the P budget of the oceans may affect estimates of the biomass of marine organisms, the biotic fixation of Cog, and therefore predictions of global climatic change.
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Birger Rasmussen (1996) studied this question.