The original Russian edition of the monograph Paleozoic salt forma- tions ofthe world was published by Nedra, Moscow, in 1974. The description of salt basins was given as of 1970-1971 and based on the literature available at that time. Additional evidence was pre- sented in History of Paleozoic salt accumulation (Nauka, Novosibirsk 1978), with abrief account of new basins of Paleozoic salt accumula- tion. These two books complement each other and have one common list of references, the former providing the material which in the latter is the basis for the major trends in the history of evaporite sedimenta- tion in the Paleozoic. History ofPaleozoic salt accumulation was the first ofthe two books to be published in English (Springer, Berlin, Heidelberg, New York 1981). The present book is the first synthesis dealing with specific Paleozoic salt formations and some salt basins. However, since the first edition was published 10 years ago, new data since then allow more accurate and detailed description of composition, structure, and dis- tribution patterns of salt deposits within Paleozoic evaporite basins. New basins have also been found in some regions of the Earth. The author has attempted to give more complete characterization of Paleo- zoic salt basins using the data available as of 1981.

The principal aim of the present work is to understand the evolution of halogenesis in the Paleozoic. To succeed in the study it was neces- sary to make a general and systematic synthesis of data available on world-wide Paleozoic halogenic deposits and describe all known eva- porite basins. This study succeeds the monograph Paleozoic Salt For- mations of the World (Zharkov 1974a). The history of Paleozoic salt accumulation is based chiefly on evidence presented in the above monograph; this work should be considered as its direct continutation. The present work mainly aims at: (1) establishment of the num- ber of both salt and sulfate basins and salt and sulfate sequences formed therein in the Paleozoic; (2) determination of the stratigraphic position of salt and sulfate sequences in separate regions, their distant correlation and recognition of stages of evaporite sedimentation during the Paleozoic; (3) determination of the volume and areas of distribution of halite, potash, and sulfate sedimentation within basins and on continents through periods, epochs, and ages of the Paleozoic to single out epochs of the most intense evaporite sedimentation; (4) reconstruction of paleogeography of continents to recognize stages of evaporite accumulation and paleoclimatic zones of halogenic sedi- mentation in the Paleozoic; (5) understanding the evolution of eva- porite sedimentation in the Paleozoic. The nomenclature used in the book should be explained.