Submarine metalliferous carbonate mounds in the Cambrian of the Baltoscandian Basin induced by vent networks and water column stratification.

Two massive precipitation events of polymetallic ore deposits, encrusted by a mixture of authigenic carbonates, are documented from the Cambrian of the semi-enclosed Baltoscandian Basin. δS (‒9.33 to ‒2.

Glendonite occurrences in the Tremadocian of Baltica: first Early Palaeozoic evidence of massive ikaite precipitation at temperate latitudes.

The Tremadocian (Early Ordovician) is currently considered a time span of greenhouse conditions with tropical water surface temperature estimates, interpolated from oxygen isotopes, approaching 40 °C. In the mid-latitude Baltoscandian Basin, conodonts displaying low δO values, which suggest high temperatures (>40 °C) in the water column, are in contrast with the discovery of contemporaneous glendonite clusters, a pseudomorph of ikaite (CaCO·6HO) traditionally considered as indicator of near-freezing bottom-water conditions. The massive precipitation of this temperature sensitive mineral is associated with transgressive conditions and high organic productivity.