Comments on Atoll Phosphate Rock
Fosberg, F. Raymond (1994). "Comments on Atoll Phosphate Rock". Atoll Research Bulletin. 396: 1–4. doi:10.5479/si.00775630.396.1. ISSN 0077-5630.
- Has attachment: File:C3AVNTEL.pdf
Abstract: Fosberg discusses previous research by Dr. K. A. Rodgers, who has documented the presence of terrestrial phosphate rock and phosphatic soil in the Tuvalu Archipelago. This area is characterized by low-lying oceanic atolls with no historical connection to continental land masses.
Fosberg expands on Rodgers’ work by describing his observations of phosphate rocks on coral islands, which he terms “atoll phosphate rock” or the Jemo Soil Series. He attributes the formation of these rocks to a unique ecological context involving dense stands of the tree Pisonia grandis and colonies of sea-birds. Bird droppings, known as guano, contribute to phosphate deposits as they are washed into the porous, acidic humus under Pisonia forests.
Through various examples from different coral islands, Fosberg argues that the presence of atoll phosphate rock can indicate previous Pisonia forests, even in locations where such forests no longer exist due to human disturbance. He also considers other potential sources of similar phosphate deposits, such as the tree Neea choriophylla on Belizean atolls, suggesting alternative ecological dynamics may produce analogous formations.
Fosberg critiques prior studies for not fully acknowledging the role of acidity in phosphatizing processes, and maintains that the distinctive brown color of the phosphate cemented rock is crucially associated with the acidic humus produced by Pisonia forests. He concludes that these phosphate formations are indicative of once-thriving ecosystems consisting of Pisonia forests and roosting sea-birds, prevalent before human alteration.
Extra details:
MAG: 2019278773 OpenAlex: W2019278773 CorpusID: 129082972
