Metasomatism and cyclic skarn growth along lithological contacts: Physical and geochemical evidence from a distal Pb Zn skarn

Distal skarns form by the metasomatic reactions of a host rock induced far-traveled hydrothermal fluids. Physical and structural characteristics geochemical patterns distal PbZn skarn bodies were studied at Petrovitsa deposit in southern Bulgaria. Skarn formed from interaction fluids with reactive lithologies (marble gneiss). These transported along sub-vertical feeder structures lithological contacts. Epidote developed gneiss protolith, pyroxene (johannsenite) marble. Detailed geological mapping, complimented measurements internal structure body using growth versors, quantifies propagation direction body: 1) away major local fluid conduit (feeder structure), 2) contacts between aluminosilicate Such suggests that flow was generally orthogonal to front skarn. Textural, mineralogical data samples reveal multiple generations calc-silicates epidote pyroxene. The is characterized limited spatial distribution fine-grained epidote/clinozoisite associated massive replacement sulfide mineralization. consists acicular clinopyroxene crystals which spheroidal aggregates discrete banding. bands are physical representation cyclic pulses resulted rhythmic marked In situ analyses early Al-rich overprinted Fe-rich higher Mn Sr contents irregular compositional Clinopyroxene (Jo60–95) shows general increase Na, Al, Mn, REE + Y distance lithologic elements correlate traveled site skarnification, we define proxy based on Al content crystals. This reflects an increasing degree “contamination” rocks functions as for transport distance. trace-elements outcrop scale indicative resulting precipitation increasingly tortuous pathway front, both macro- micro-scale chemical textural variability body.