Gold in lower Paleozoic conodont elements of Baltoscandia

Native gold has been found in the coquina-type phosphorites of the Kingisepp deposit. However, the author cannot rule out the presence of terrigenous gold particles in the sample, because the floatation concentrate of phosphorite ore was studied. The possible contamination of the heavy fraction with clastogenic gold is evident from the occurrence of some rounded grains and an element composition of gold similar to that of native gold from deposits in the Baltic Shield. The Au content in brachiopod shells and conodont elements from Lower Paleozoic sections of Baltoscandia amounts to tens of g/g. Such Au enrichment is typical of biogenic apatites extracted by acidic maceration from both terrigenous and carbonate rocks. Accumulation of Au by Early Paleozoic biogenic apatites is a relatively well-substantiated fact, although its occurrence form is unknown so far. Presented are data on the element composition and morphology of gold particles extracted from Lower Paleozoic conodont elements with elevated Au concentrations.