Hydrohematyt pod Ciechocinkiem oraz uwagi tektoniczne

Abstract

HYDROHEMATITE NEAR CIECHOCINEK AND TECTONIC AL REMARKS Summary When examining the bog-ore deposit at Pokrzywno, near Ciechocinek, attention was paid to the presence of earthy iron ore, hydrohematite, cherry-red in colour. A similar sediment is being laid down, at present, around the site of brine outflow at Stawki, near Aleksandrów Kujawski. Chemical analyses of both sediments have shown an analogous association of metals, and a great percentage of chlorides. These suggest the hydrothermal genesis of the deposits. Analysing the geochemical conditions, which existed during the formation of these deposits, and considering the geological structure of the adjacent area, it may be assumed that under the Ciechocinek area a 12 km long dislocation line exists, stretching in a WE direction. Along this line (active still at the Holocene time and probably also at present) a displacement of the Pomeranian anticlinorium may distinctly be seen in relation to the Kujavian anticlinorium. A possibility of hydrothermal genesis of iron ore deposits in the Dogger formations of Middle Poland has also been taken into account. Stages of ore mineralization would depend upon stages of dislocations.