engleski

Stop 3: Glauconitic sandstones of the Vučji Jarek

Mineralogical and sedimentological characteristics of the Lower Miocene glauconitic sandstones of Vučji Jarek member of Macelj formation are described. The fossil association and glauconite grains documents a shallow marine environment while the planar and trough cross-bedding suggest deposition by traction. The composition and thickness of glauconitic sandstones indicate a strong terrestrial influence and tidal deposition during a long period. Glauconitic material separated from the Vučji Jarek member, deposited within a marine, nearshore environment under tidal influence, and the overlaying Čemernica Mb., formed in the offshore-transition zone between shoreface and offshore, were compared. X-ray powder diffraction, infrared and Mössbauer spectroscopy, as well as chemical methods indicate that glauconitic materials from the Vučji Jarek Mb. are evolved while those from the younger Čemernica Mb. are slightly-evolved to evolved.

glauconite, sandstone, clay minerals, Hrvatsko zagorje, Vučji Jarek member, Čemernica member, Macelj formation

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