Evaporites

elective courses

The lecture concerns the genesis of evaporite rocks (sediments built of easily soluble salts precipitated from natural solutions, as a result of or with the participation of evaporation) and focuses on sedimentological, petrological and geochemical problems, primarily on modern environments and sedimentation processes of these deposits.

Definition of evaporites. Evaporation. Salt minerals and their features. Classifications of evaporites. Occurrence of ancient evaporites on Earth and their age. The largest saline giants. Evaporite basins and their fundamental models. Precipitation of salt minerals. Factors determining the formation of evaporite basins and evaporite deposits (climatic, morphological and tectonic factors). Paleogeographic significance of evaporites. Water of evaporite basins - its hydrographic structure. Heliothermal lakes. Salinity of evaporite basins water. Characteristics of brines. The chemical composition of sea water and its evaporation. Marine saltwork pans, their functioning and production of sea salt. Organic world in brines. Recent microbial mats and microbialite deposits (microbialites) associated with brines. Microbialites and stromatolites associated with fossil evaporites. Shallow-water sedimentation in marine saltwork pans - gypsum microbialites and selenite deposits (selenite), halite deposits. Deepwater sedimentation of gypsum and halite in the Dead Sea. Changes in the chemistry of seawater during its evaporation and precipitation of salt minerals. Sequence of crystallization of marine potassium-magnesium salts. Ideal and real crystallization sequences. Potassium-magnesium salts and the chemical evolution of the ocean. Precambrian evaporites. Evaporites crystallizing from freezing brines. Salt lakes of Antarctica, cold and polar zones. Modern environments of evaporite sedimentation and their division. Salt lagoons. Marine salinas. Marine and continental sabkha. Salt lakes and their chemistry. Chemical evolution of salt lakes. Environment of salt lakes - permanent and periodic lakes. Evaporites of the weathering zone. Ancient evaporative basins and their development. Badenian Forecarpathian Basin. Messinian evaporites of the Mediterranean. The Zechstein Basin. Diagenesis of evaporites. Salt tectonics and salt diapirism. Salt glaciers. Exhumation of evaporites and their weathering. Salt karst.

The lecture teaches understanding of geological processes leading to the formation of various types of evaporitic rocks (mainly gypsum, anhydrite, rock salt), understanding the genesis of sedimentary and diagenetic structures occurring in them, as well as understanding the processes leading to the creation of large-scale geological structures such as diapirs and "salt glaciers". The lecture teaches the basics of chemical sedimentology, helps to understand the origin of chemical deposits associated with evaporites. The lecture also teaches some issues related to regional geology of Poland and of the world. The lecture teaches the Polish and the English-language scientific terminology.

The final test checking the level of knowledge acquired during the lecture.

In the case of conducting classes remotely (On-line), assessment may be based on the assessment of self-prepared written works on a given topic.

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