On the origin of phosphorites from Christmas Island in the Indian Ocean

Autor: E. A. Zhegallo, G. N. Baturin, E. L. Shkol’nik
Rok vydání: 2008
Předmět:
Zdroj: Oceanology. 48:94-104
ISSN: 1531-8508
0001-4370
DOI: 10.1134/s0001437008010116
Popis: A detailed investigation of microstructures of the phosphorites from Christmas Island under a scanning electron microscope coupled with an analysis of their chemical composition revealed that both their structure and composition are quite similar to those of the granular and microgranular phosphorites on present-day continents, as well as those of the phosphorites on some of the Pacific guyots. Their composition, together with their geological position and interrelationships with the surrounding rocks, proves that the ornitogenic hypothesis based on the presumed guano accumulation followed by its transformation into phosphatic rock is not compatible with the field observations. Meanwhile, the problem of the source of the Fe and Mn impregnation in the phosphorites remains unresolved and needs further investigations.
Databáze: OpenAIRE