ASSESSMENT OF PROVENANCE SIGNATURES, MATURITY, WEATHERING AND THE TECTONIC SETTINGS OF STREAM SEDIMENTS FROM SHEET 202 SHARE (SW) NORTH CENTRAL NIGERIA.

Abstract

Geochemical study on the Sheet 202 Share SW stream sediments was carried out to infer their provenance, maturity, classification, tectonic setting and source-area weathering. The discriminant functions of the major oxides were plotted and revealed a mixed felsic/basic intermediate igneous provenance. The source characteristics of sediments are constrained with the Sr vs. Ba plot in which the Share SW sediments plots within the field of mature sediments. The chemical maturity of these sediments are also confirmed with the moderate Zr–Hf content since Hf and Zr are closely associated in sediments and are both concentrated in zircon. The Share Sheet 202 SW stream sediments display high La (383–1300 ppm) contents reflecting felsic input. Therefore, the La-Th-Sc ternary plot was used to determine the source of contamination of the Share SW sediments which fall within the field of granitic gneiss sources. Similarly, the discrimination diagrams of tectonic were used to evaluate the tectonic setting of the Share SW stream sediment samples with samples cluster at the passive margin. The Share SW sediments tectonic  setting  is of  the  passive continental  margin, while  the provenance  is the  intermediate igneous  sediments  of mature continental provenance,  associated  with  a continental  passive  margin, in a recycled  orogenic province.