GEOCHEMICAL AND MINERALOGICAL CHARACTERISTICS OF IRON ORES FROM PARTS OF RAJASTHAN

Abstract

The iron ore at Morija, Jaipur occur as massive type between quartzite and schist, iron ore at Taonda, Sikar and Jhunjhunu occurs as lenticular iron ore bodies of the Precambrian Delhi super group. The megascopic and microscopic study of samples shows that the major minerals present in these iron ore deposits are hematite and magnetite, and quartz. Hand specimen and textural study revealed that iron ore has been enriched from banded iron formation of Precambrian age, which is massive nature due to high degree of deformation and metamorphism. The source of iron input originally from the banded iron formation and it should be volcanic. From the geochemical study it has been inferred that the origin of iron ore is volcano-sedimentary. A remarkable variation of geochemical properties has been found in both study areas through X-Ray Fluorescence (XRF) analysis. Major mineralogy of ore sample from both the areas constitutes (Fe203) IotaI and silica (SiO2) constitutes nearly 97 to 99 % of the total iron formations. Major chemical composition of both study areas illustrates that iron ore deposition is similar to Lake Superior and Odissa type banded iron formations. The triangular plot of A1203-Fe2O3-SiO2 shows that the iron formation is belonging to the Precambrian iron formation. The low concentration of P205 (.09) and absence of sulphur (s) indicates that the iron ore is of high grade. Lower concentration of A1203, CaO, MnO, Na20 and K20 values prove that the iron formation is of sedimentary/ volcano-sedimentary origin and their source of sediment supply should not continental derived. The trace element distribution patterns of Morija and Taonda iron formation are essentially similar to Lake Superior type banded iron formation. Concentration patterns of various trace elements shows that the origin of these iron formations supports sedimentary deposition iron formation.