MATURITY AND PROVENANCE OF THE ALBIAN BIMA SANDSTONE IN WURO-DOLE AND ENVIRONS, YOLA ARM, NIGERIA.

Bima Sandstone at Wuro-Dole and environs was studied for its level of maturity and source area (provenance). In evaluating its textual maturity and provenance, field mapping was carried out and representative samples were subjected to physico-chemical and mineralogical analyses. The sandstone consists of some primary sedimentary structures:cross-beddings and ripple marks. Strike measurements of these primary structures plotted on current rose diagrams indicated SSE-NNW and NE-SW/NW-SE directions. The Bima Sandstone is averagely made up of medium grained, poorly-sorted, fine skewed and very leptokurtic, angular sandy sediments. Petrographic study revealed about 57.3% quartz, 18.8% feldspar, 3.5% mica, 10.5% rock fragment, 5.1% cement, 2.4% heavy minerals, and 2.5% matrix. On the basis of framework composition of quartz, feldspar and mica + rock fragment, the sandstones of Wuro-Dole were grouped as lithic subarkose with a few of lithic arkose variety. They are generally immature. Concentrations of major oxides include SiO2 (75.9%), Al2O3 (14.2%), Fe2O3 (4.6%), Cao (0.6%), MgO (0.16%), Na2O (1.2%), MnO (0.12%), TiO2 (0.14%), and K2O (2.6%). These geochemical results further validate that of mineralogical analysis in that the sandstone consists mainly of SiO2, Al2O3, Na2O and K2O which is reflection of the presence of quartz and feldspar. Heavy mineral separation showed that the Bima Sandstone is made up of rutile, zircon, tourmaline, sphene, staurolite, sillimanite, and apatite; these heavy mineral assemblages are indicative of mainly felsic igneous and high grade metamorphic rocks. Granite and gneiss suites of both Southeastern and North Central Basement Complexes of Nigeria have been suggested as the probable source areas of the Bima Sandstone