REE Biological Metallogeny —A Preliminary Study

Five species of bacteria have been found in granite-weathering profiles of Ore District 701.They tend to decrease in varieties and quantities from the upper part down-ward, and no bacterium has been brought up below the depth of 10 m.The simulating experiments done by using humic acid of small molecular weight ,and decanedioic acid extracted from the samples and the bacteria mentioned above have shown that:(1)The dissolving rates of REEs from humic acid+original rock or decanedioic acid +original rock are lower than those from humic acid +bacteria +original rock or decanedioic acid +bacteria+original rock.The presence of bacteria may accelerate the formation of REE-organic complexes and make the complexes increase in quantity.Aminoacids in the bacteria are involved in coordination balance.The concentrations of the complexes tend to increase as a result of the formation of the complexes,i.e., the dissolution, complexation, migration and accumulation of REEs from the original rocks will be accelerated.(2)The metabolism of microorganisms has contributed a lot to keeping a pH environment in the weathering crust.

Five species of bacteria have been found in granite-weathering profiles of Ore District 701. They tend to decrease in varieties and quantities from the upper part downward, and no bacterium has been brought up below the depth of 10 m. The simulating experiments done by using humic acid of small molecular weight, and decanedioic acid extracted from the samples and the bacteria mentioned above have shown that: (1) The dissolving rates of REEs from humic acid + original rock or decanedioic acid + original rock are lower than those from humic acid + bacteria + original rock or decanedioic acid + bacteria + original rock The presence of bacteria may accelerate the formation of REE-organic complexes and make the complexes increase in quantity. Aminoacids in the bacteria are involved in coordination balance The concentrations of the complexes tend to increase as a result of the development and growth of bacteria. So the balance shifts in the direction toward the formation of the complexes, i e., the dissolution, complexation, migration and accumulation of REEs from the original rocks will be accelerated. (2) The metabolism of microorganisms has contributed a lot to keeping a pH environment in the weathering crust