Home – Home – Jornals – Russian Geology and Geophysics 2004 number 5

Different hypotheses of phosphorite formation are based on the supposed existence of hypogene sources of phosphorus whose intensity is responsible for the rhythmicity of accumulation of large subsynchronous deposits of phosphorites. Comparison of volcanic and exhalation activities with epochs of phosphorite accumulation, considered to be of global importance, is not safe and is even false in some aspects. The formation of large deposits of rich phosphorites shows a poor correlation with the supposed intense supply of phosphorus from depth. It has been shown that a set of paleogeographical conditions rather than phosphorus concentration in oceanic waters by endogenetic processes is of critical importance. The intensity of an uncertain phosphorus source feeding the sea waters is not crucial for formation of large deposits of phosphorites. The critical factors are the way of mineralization of phosphates and mechanism of their accumulation to form a deposit.