50-lecie odkrycia złoża węgla brunatnego w Złoczewie

At the beginning of1962, a brown coal deposit has been discovered by the Złoczew IG-1 borehole drilled in the centre of a local negative gravity anomaly in Central Poland by the Polish Geological Institute. Thorough exploration of the deposit has established its brown coal reserves for about half a billion tons. Additionally, the discovery provedfor the first time that negative gravity anomalies could also be caused by brown coal concentrations, and not only by salt diapirs.