Among rare earth elements (REEs) deposits of sedimentary type is a phosphorite deposit containing REEs, which are distributed in DPR Korea, China, Algeria, Tunisia, Pakistan, Israel, Syria, Morocco, Canada, etc.
The phosphorites of the lower Cambrian strata are relatively widely distributed in Yunnan Province, Guizhou Province, Jiangxi Province, Zhejiang Province and Jiangsu Province of China, in which the geochemical characteristics of P2O5 and REEs have been studied in detail. Most of the studies have been focused on elemental geochemistry and sedimentary environment. However, they have only dealt with the characteristics of distribution and variation of REEs in the basal phosphorite of lower Cambrian but not with overlying strata.
Kim Kwang Chol, a section head at the Faculty of Earth Science and Technology, has investigated the REE content and its distribution characteristics of the phosphorous siltstone developing in the middle part of the lower Cambrian strata.
He studied the characteristics of mineral composition and REE composition of sedimentary rocks of the lower Cambrian strata of Hwangju-Yonthan area in the DPR Korea by microscopy observation, chemical analysis, ICP-MS analysis, XRD analysis and infrared ray (IR) spectroscopy, etc. The result has shown that the phosphorous siltstone in the middle layer contains appreciable amounts (generally from 340.0 to 1 105.6ppm) of REEs. This phosphorous siltstone layer is more than 15-21 meters thick, over several hundred meters long in the strike extension, and has high HREE content (HREE/ΣREE ratio is generally from 0.232 9 to 0.394 7).
This result seems to have valuable applicability, especially in the search for and evaluation of HREE deposits in all areas where the low Cambrian strata develop.
© 2021 KumChaek University of Technology