Notes on a pyritic zone in upper Ancylus sediments from the Bothnian Sea

Abstract

Branchlike aggregates, several millimeters in length, of microscopic pyrite spherules are abundant in a narrow zone in upper Ancylus clay deposited approximately 7 500 yrs B.P. in the southeastern part of the Bothnian Sea. The aggregates in general, and often also the individual pyrite spherules, have crusts of marcasite exhibiting a radial growth pattern.