Photoluminescence and Raman Spectroscopy of Jurassic Fe-Mn Oxide Rocks Forming Chimney Systems, Hungary

摘要

Three ore samples were collected from an inferred hydrothermal vent site at the Urkut-Csardahegy open pit mine. The samples are black with a brown rind, blocky or moundlike with stromatolitic texture, cryptocrystalline, and often with vugs infilled by spherulites. Fe-Mn-oxide stromatolitic mounds grew at the sediment/water interface burying preexisting chimneys containing fluid-flow microchannels. The occurrence of amorphous carbon phases in the samples is variable and their distribution is inhomogeneous, and suggests a possible microbial origin. The occurrence of gypsum may reflect a Fe-S precursor phase. These results provide additional evidence for the existence of a local vent system at Csardahegy.