Comparative Research On The Features Of Potash Formation Of Saskatchewan Basin And The North Shanxi Basin

With rich potash resources, Saskatchewan of Canada has a long history of salt mining. The exploration and development there is mature, so it is one of the most sophisticated potash deposits in the world. The north Shaanxi basin is representative in the marine potash deposits that have been discovered in China. Based on the previous studies, this paper, by discussing the regional and deposit geological characteristics of Saskatchewan basin and combining the resource development and investment environment of the potash resource of Saskatchewan, explores the source of minerals, salt layers, ore-controlling conditions and other related geological problems. In addition, this paper has conducted a comparative research on the features of potash formation of Saskatchewan basin and the north Shaanxi basin so that we have deepened our understanding in the law of potash formation. The conclusions are:(1Saskatchewan is shallow-marine shelf basin. The basin, located in the most distant lake chain, has a poor communication with the open sea so as to form a multi-level sub-basin. With the water progressively concentrated, the climate persistent drought and seawater evaporated strongly, three evaporation salt layers have formed, becoming the world’s largest potash deposits.(2)North American phanerozoic would drift from the southern hemisphere to the northern hemisphere with counterclockwise along with left-handed. The equator was in the northern end of the continent in Cambrian, moved to northern North America in Silurian-Devonian, in the southern United States in Permian, and started position away from the North America in Jurassic, making Saskatchewan basin located with favorable climatic conditions.(3)Affected by late formation and biogenic reef, Great Basin of Saskatchewan was divided into three sub-basins, with Saskatchewan potash basin located in the lowest sub-basin in the southeast corner of the Great Basin. Basin in northern Shaanxi developed from west to east four depressions, and trend in a north-east direction.(4)Elk Point research area of Saskatchewan basin has gone through four large transgressive-regressive cycles, forming four regional evaporite rhythms. Majiagou salt strata of Ordovician in northern Shaanxi basin, mainly formed by evaporation and carbonate rocks interbedded alternatively is typical marine chemical salt deposits.Based on the macro-geological conditions, such as tectonic setting, the ancient latitude, paleoclimate, basin tectonic, basin scale and mineralization age, etc., the paper summarizes the metallogenic conditions of Saskatchewan basin and northern Shaanxi basin; micro-geological conditions contain:whether it has reached potash deposit stage, in which layer the potash forms, at what (ancient) tectonic position the potassium forms, at which (new) construction site to find potash, as well as material sources and basin shape. Through the comparison of macro-and micro-geological conditions, the paper takes Saskatchewan as a typical example to provide a reference work for the potash finding in the northern Shaanxi basin.