Sedymentacja i geochemia najstarszej soli kamiennej w rejonie Zatoki Puckiej

Abstract

SEDIMENTATION AND GEOCHEMISTRY OF THE OLDEST ROCK SALT IN THE PUCK EMBAYMENT AREA Summary Sedimentological and geochemical studies on the oldest rock salt in the Puck Embayment area made it possible to solve several questions connected with origin and conditions of sedimentation of the salt packets. The salt formation as a whole represents the type of primary salts, formed in a basin with diversified bathymetry and dynamic conditions and corresponding to modern sebkha and salina environments. Differences between dynamic conditions in deep and shallow parts of the basin resulted in origin of specific structural-textural sequences. The oldest rock-salt sequences have originated in 2 sedimentary megacycles, developed in a regressive sequence. The cycles are characterized by predominance of chlorine facies in deep parts of the basin, where accumulation has been compensated by subsidence and, therefore, water depth relatively stable. In iones of sea-floor elevations, precipitation of chlorines was accompanied by that of sulfates. The second megacycle reflects supply of clastic and detrital material from land. This resulted in origin of salt series contaminated with that material in areas of sea-floor elevations. Such „polluted" sediments were previously interpreted as secondary, i.e. so-called descendant salts, whereas they actually represent a facies variety of original, „pure" salts.