01-P-10 - Heulandite group zeolites from the Paleogene fresh water lake Blateshnitza Graben, Southwest Bulgaria

Publisher Summary This chapter discusses Heulandite group zeolites from the Paleogene flesh water lake Blateshnitza Graben, Southwest Bulgaria. The Blateshnitza Graben is a continental fresh water lake basin filled with polymictic conglomerates, breccia-conglomerates, and strongly subordinated sandstones. In the lowest volcaniclastic bed, found in the upper part of the Zemen bore core, heulandite group zeolites, and probably ferrierite are identified by optical microscopy, scanning electron microscope (SEM), X-ray diffraction (XRD), and differential thermal analysis (DTA). Judging from the thermal stability, the main zeolite is heulandite, but the chemical data suggest that it should be considered as clinoptilolite. The features of the geological position and the environment of deposition suggest a zeolite genesis in an open hydrologic system.