RHYTHMICALLY BANDED QUARTZ-ADULAR GOLD-SILVER VEINS IN DUKAT DEPOSIT (OKHOTSK-CHUKOTSKY VOLCANIC BELT) - AS A RESULT OF SELF ORGANIZATION

摘要

The object of the study was a sample from rhythmically banded quartz-adular-argentite vein containing the berthierine zone. Detected: therein metasomatic zonality corresponds in the whole to an acidic type but contains some zones with redeposited Al and Fe also. There are two kinds of rhythmical banding: quartz-adular and berthierine-adular. The former is close to the host rock, and the last one is emplaced nearer to vein. Adular shows monoclinic features and corresponds to a poor-in-K variety. Berthierine has the high content of iron and sometime contains an admixture of chlorite. Both berthierine and adular represent the metastable phases deposited within an extremely unequillbrium environment. The studied rhythmically banded structure appears to be a result of dissipation in hydrothermal solution. Proposed mechanism of such a dissipative structure origin is based on the system of equations characterizing a complex set of homogeneous and heterogeneous reactions, with a particular role of oxidation-reduction reactions. The last ones are the trigger to start up oscillations of the solution composition.