Quantification of mass transfer during fluid-rock interaction at the Jahaz uranium deposit, North Delhi Fold Belt, India

The Jahaz area belongs to the Mesoproterozoic metamorphic rocks of the North Delhi Fold Belt, India, and is composed of garnetiferous quartz biotite schist (GQBS), amphibolite, graphite schist, and quartzite (Jain et al., 2016). It lies within the well-known Na-metasomatic uranium deposits along the “albitite line” of the Khetri Belt, Rajasthan (Ray, 1987). This work involves the whole-rock geochemical analysis of major, trace, and rare-earth elements in less to moderately altered (LTMA) and albitized host rocks, using XRF and ICP-MS. The alteration box plot and isocon analyses were attempted to quantify the exchange of chemical components during fluid-rock interaction. The alteration box plot corroborated the intensity of alterations such as albitization, chloritization, calcitization, actinolitization, sericitization, and linked to the Na-K-Ca-Mg metasomatism, which was responsible for the formation of various altered minerals in the metasomatic rocks (Mishra et al., 2022). The correlation coefficient plots indicated that elements such as Zr, Nb, Hf, and Tiwere less mobile during fluid-rock interaction. Isocon analysis supports the enrichment a positive correlation exists between U and Na, Mo, Cu, Th, Zr, LOI, and LREEs in the zones of intense rock alteration (Grant, 2005). The low Th/U ratio of albitized GQBS indicates that the albitized rocks are significantly enriched in uranium. Therefore, uranium enrichment is positively correlated with Na, Mo, Cu, Th, Zr, LOI, and light rare-earth elements in albitized GQBS, as well as amphibolite, in the Jahaz U-deposit. These enrichment and depletion trends match with the Kirovograd and Novoukrainka (Ukraine), Lagoa Real (Brazil), Valhalla (Australia), Longshoushan (China), Aricheng (Guyana), and Coles Hill (USA) Na-metasomatic Uranium-deposits. The outcome of the present work can be useful to exploration agencies in targeting Na-metasomatic U-deposits more precisely in other areas.