Soczewka soli Klęczki z olistostromowych utworów Wieliczki

Andrzej Ślączka, Krystyna Kolasa



Within the upper part (salt breccia - Zuber) of the Wieliczka salt deposits (middle Miocene) there are lenses built up of conglomerates and laminated salt (Figs. 1-4). Hitherto it was belived that these lenses represent tectonic schuppen derived from stratified salt which underlies the breccia. Recent studies conducted in the Wieliczka salt mine shown that the breccia deposit is a series of olisthostromes (3) and laminated salt is an integral part of them.
The latter represents the uppermost part of the sequence deposited by a single sediment gravity flow. There is a continuous transition from olisthostroma via conglomerates into parallel and cross-laminated salt (ryc. 5, 8-14). In whole sequence there are randomly dispersed outsized blocks of Miocene claystones. The clastic material of conglomerates and laminated salt consists almost exclusively of salt pebbles, salt grains and broken salt crystals. In small quantities occur clasts of Miocene mudstones, quartz grains and Miocene foraminiferas (ryc. 6, 7, 9). The gravity flow started as cohesive debris flow which involved into surging high-density turbidity current. Fluctuations in the rate of suspended-load fallout resulted in sedimentation from traction carpet, traction and suspension (ryc. 16).
The complete sequence in the Wieliczka breccia deposit is remarkably rare, usually these deposits are represented by thick beds of sediments deposited by cohesive debris flows only or by debris flow associated with gravelly division of high-density turbidity current (pebbly mudstone + graded or inverted graded conglomerates).
The above mentioned mechanism of transport could been modified by influence of high density of salt water in which sedimentation took place.

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