Chemostratigraphy of the Cretaceous Yolde Formation in Yola Sub-Basin, Northern Benue Trough, Ne Nigeria

Abstract

This research aims to determine the chemostratigraphy of the Yolde Formation. The formation has been inadequately studied  systematically in the light of chemostratigraphy. The existing works on the formation either lack representativeness in terms of the  proxies used or are subjective during their division procedures. From the field studies, five (5) samples of sandstone and shale units of  the Yolde Formation were collected. The samples were analyzed for both major and trace elements using an X-ray fluorescence machine.  The following geochemical parameters were studied; Al₂O₃, Al₂O₃/Fe₂O₃, KO₂/Al₂O₃, TiO₂/Al₂O₃, CaO, Cr, Rb/Sc, and Zr. From the studies,  six (6) chemozones were identified in the Yolde Formation. Transgressive and regressive depositional sequences were observed  with a significant sequence boundary of maximum flooding surface which is a time-significant feature. The chemostratigraphic scheme  could not only be comparable to the regional sequence stratigraphic scheme but also more objective and higher resolution. This research  gives a systematic chemostratigraphic analysis of Yolde Formation, which testifies to the feasibility and potential of the usage of  chemostratigraphy for stratigraphic development.