Super-Enrichment of Dispersed Elements and Associated Ore Deposits

TheeightelementsGe ,Ga ,In ,Tl,Re,Cd ,Se ,andTeareusuallyreferredtoasdispersedelements.Therehasbeennostrictdefinitionpertainingtodispersedelements,andthedispersedele mentsrefertothoseelementswhichhavealoweraverageabundanceinthecrust (usuallyontheor derof 10 -6-10 -9) ,sosomescholarsholdthatthosedispersedelementscouldnotformindepen dentoredeposits.TheGrandEncyclopedia (thevolumeofgeology ,1993 ) presentssuchadescrip tionas:“Dispersedelementscannotformindependentoredepositsandtheyarepresent…

Super-enrichment of dispersed elements and associated ore deposits

Dispersed elements do not always occur as associated elements in the ore deposits of other elements. Instead, they can constitute independent ore deposits. The focus of this paper is placed on the mechanism of super-enrichment of the four dispersed elements TI, Ge, Se, and Te under favorable geological conditions, where their enrichment coefficients are so high that their abundances can reach n×103-n×104, sometimes even up to n×106 times (e. g. Te) those of the crust. As a result, they can form their independent ore deposits. Studies have shown that such independent ore deposits are mostly distributed in the southwestern part of China, most of which belong to low-temperature ore deposits, ranging in age from Yanshanian to Himalayan(Cretaceous to Cenozoic), with a significant time gap with the host strata. Moreover, this paper also deals with the existing forms (as independent minerals, occurring isomorphously and being adsorbed) of the dispersed elements in those independent ore deposits. The discovery of independent ore deposits of dispersed elements is a great breakthrough in the study of dispersed element metallogenesis.