Trace and Rare Earth Elements Geochemistry of the Mudstone Rocks from the Injana Formation: Implications for Provenance and Paleoclimate

Abstract

Late Miocene-Pliocene mudstones of the Injana Formation were examined to provide insight into the nature of the source rocks and paleoclimate. For these purposes, 23 mudstone samples from three locations Mirawa and Degala in the Erbil, northern Iraq and Najaf from southern Iraq. These samples were analyzed by ICP-MS to measure the concentrations of the trace and rare-earth elements (REE). The chondrite-normalized REE of all samples are similar and shows slight enrichment with LREE relative to the HREE with negligible negative Eu anomaly. The discriminant plots of the trace elements and the enrichment factors suggest that the source was intermediate-mafic rocks, and the climate was warm and humid during the deposition of the mudstone of the Injana Formation.