New Understanding of Boundary Fault Control of Potassium Sag Formation in the Majiagou Period of the Ordovician in the Eastern Margin of the Ordos Basin
New Understanding of Boundary Fault Control of Potassium Sag Formation in the Majiagou Period of the Ordovician in the Eastern Margin of the Ordos Basin
The Ordovician Majiagou Formation in the northern Shaanxi salt basin has good potential for potassium mineral formation,but only thin potassium beds and thick beds of potassium mineralization,rather than large-scale potash,have been found.As a result of performing a structure analysis of seismic profiles in the eastern margin of the Ordos Basin,we believe that there was a boudary normal fault in the period of deposition of the sixth submember of the Majiagou Formation in the Jinxi flexure fold belt.The boudary normal fault formed a syndepositional depression,and a large amount of brine rich in potassium accumulated within the sag.With continuing drought,strong evaporation,and continuous enrichment,a brine potassium window appeared,and large-scale sylvine separated out,forming a monoblock of high-quality,marine,solid potassium salt deposits.During the Mesozoic Era,compressional stress caused the potassium sag to rise,forming a pattern of ancient depression and subsequent uplift.The potassium salt beds were uplifted to the shallow part of the basin,which is convenient for economic exploitation by the water solution method.
关键词
鄂尔多斯盆地东缘/晋西挠褶带/奥陶系马家沟组/海相钾盐/构造成钾/古凹今隆
Key words
eastern margin of Ordos Basin/Jinxi flexure fold belt/Ordovician Majiagou Formation/marine potash/structural forming of potassium/depression in ancient and upheaval in present
维普
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