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I'm not a geologist; did I misunderstand the Wikipedia entry I linked? It says - "Because of their high density, monazite minerals concentrate in alluvial sand
by perihelions 2y ago
I'm not a geologist; did I misunderstand the Wikipedia entry I linked? It says
- "Because of their high density, monazite minerals concentrate in alluvial sands when released by the weathering of pegmatites. These so-called placer deposits are often beach or fossil beach sands..."
And I found two specific examples of notably radioactive monazite beaches—an 800 km stretch of Brazil's coast [0], and 55 km stretch of India's coast [1].
[0] https://en.wikipedia.org/wiki/Guarapari#Radioactivity https://en.wikipedia.org/wiki/Guarapari#Radioactivity
[1] https://www.thehindu.com/sci-tech/No-major-birth-defects-found-in-high-level-natural-radiation-areas-of-Kerala/article12543736.ece https://www.thehindu.com/sci-tech/No-major-birth-defects-fou...
- welder 2y agoDepends on the beach. Brasil has more than others. https://www.youtube.com/watch?v=vdHHUGwFoJE https://www.youtube.com/watch?v=vdHHUGwFoJE
- snakeyjake 2y agoThose locations, with their high concentrations ("high" being "greater than 0.01%-ish") of heavy metals, of which mazanite is but one of many, are the rare exception. The IAEA report on Guarapari specifically says "it's weirdly high, brah": >The exposure level due to monazite sand radiation in Areia Preta beach, Guarapari, is high. The activity concentration of 232Th in Areia Preta is higher than others beaches in world studied. The values of the absorbed dose rate in air and outdoor annual effective dose rate in Areia Preta beach are higher than the world averages due the content of 232Th. Areia Preta is also has higher background found in beaches in world. https://inis.iaea.org/collection/NCLCollectionStore/_Public/43/046/43046452.pdf https://inis.iaea.org/collection/NCLCollectionStore/_Public/...