Petrogenetic and Distribution of Trace and Rare-Earth Elements in the Marble from Igarra Area, Southwest Nigeria.

Abstract

A multivariate statistical and upper background methods were used to interpret geochemical data of the trace and rare earth elements in the marble from Igarra in order to determine the provenance and elemental mineralized anomalies. Correlation matrix showed that Th correlates positively with both the light and heavy rare earth elements as well as Pb. The presence of Th and Pb in the marble reflects their mutual association as light ion lithophile elements (LILE) that show radioactive mineralization . Most of the calculated trace elements concentrations are within the background values except elements Ba, Sr and Zr whose contents in some samples exceed the upper background thresholds (UBT) of 68.77ppm, 1702ppm and 14.13ppm respectively. The rare earth elements (REEs) that exceed the UBT are La, Ce and Y. The viability of these anomalous elements is doubtful. The geochemical data reveal a depleted concentration of the heavy rare earth elements, (HREE) Eu ( 0.04-0.17ppm),Tb (0.01-0.2ppm), Er ( 0.09-0.7ppm) and Lu ( 0.03-0.1ppm) and an enriched light rare earth elements, (LREE), La(0.8-10ppm), Ce(1.4-11.6ppm), Pr(0.15-1.27ppm) and Na(0.5-4.3ppm). The marble contains measureable amounts of volatile materials represented by very high contents of loss on ignition (LOI). Enriched light rare earth elements (LREEs), incompatible elements Ba(24-122ppm), Sr(1076-2790) and Rb(1.95-7ppm) with  high contents of volatile materials and depleted concentration of HREEs are characteristics suggestive of mantle-  materials derived from metasedimentary rocks.

Keywords; Provenance, mantle material, multivariante and factor analysis.