Article http://dx.doi.org/10.1007/s12303-017-0066-9 pISSN 1226-4806 eISSN 1598-7477 Geosciences Journal GJ Provenance of shales and sandstones from the Devonian Accraian Group, southern Ghana Chris Y. Anani*, Daniel Kwayisi, Naa A. Agra, and Daniel K. Asiedu Department of Earth Science, University of Ghana, P.O. Box LG 58, Legon-Accra, Ghana ABSTRACT: Petrographic and whole rock geochemical studies were carried out on sandstones and shales of the Devonian Accraian Group of southern Ghana to constrain their provenance and tectonic setting. Modal petrographic analysis on the sand- stones show that the framework grains are sub-angular to rounded in shape. Upper continental crust normalized multi-element plots, as well as trace element ratios, suggests that the sandstones and shales were mainly derived from felsic and recycled sources. Modal mineralogy of the sandstones, and major and trace element geochemistry of sandstones and shales further suggest that they are of recycled orogenic provenance. Discriminant function based major-element diagram suggests that the Accraian sandstones and shales were deposited in a Passive margin setting. Weathering indices suggest high degree of source area weathering. It is of the view that the Accraian sandstones and shales, most probably, received sediment input mostly from the Paleoproterozoic Birimian metased- imentary rocks and their associated granitoids and/or the Neoproterozoic sedimentary rocks from the Volta Basin which are both positioned northwest and north, respectively, of the Accraian sedimentary rocks. Key words: geochemistry, provenance, Pan-African, Accraian, Ghana Manuscript received February 13, 2017; Manuscript accepted October 2, 2017 1. INTRODUCTION Provenance studies would assist in elucidating the lithospheric history of the Earth. In sedimentary petrology, according to Weltje and Eynatten (2004), provenance includes all factors related to the production of sediment, with specific reference to the composition of the parent rocks as well as the landform and paleo-climate of the source area from which sediment is derived. The understanding of the source and tectonic setting of siliciclastic rocks has evolved over the years by studying their texture and composition. Standard petrographic approach to the identification of source rock of sandstones have been investigated by the use of polycrystalline and undulose nature of quartz grains (Basu et al., 1975), types of feldspar present (Pittman, 1970) and rock fragments (Pettijohn et al., 1987). However, petrographic examination of clay particles could be quite useless and less informative due to the diagenetic alteration of clay minerals, the main constituent of shales. Thus, more recent studies have focused on the chemical composition of shales for their provenance and paleo-environment investigation (Cullers and Podkovyrov, 2000; Bhat and Ghosh, 2001; Lee, 2002; Hofmann et al., 2003). It must be noted that the long transport distances characteristic of muds favour mixing of particles from different sources. Because of this long transport with potential for mixing, the mineralogy and chemistry of marine mudstones averages provenances from large areas and over extended periods of time compared to sandstones, which tend to reflect more immediate sources. This contrast provides the potential to obtain two somewhat different kinds of provenance information from study of a terrigenous section. REEs, Th, Sc, and the high field strength elements have very short residence times in the water column, and thus are transferred almost quantitatively into the sedimentary record hence are useful elements for assisting in identifying source-area composition (Taylor and McLennan, 1981, 1985). The sedimentary rocks which are so well exposed on the coast of Accra, Ghana, are the deposits of a shallow ancient sea which existed in the Devonian period approximately 360 million years *Corresponding author: Chris Y. Anani Department of Earth Science, University of Ghana, P.O. Box LG 58, Legon-Accra, Ghana Tel: +233-205694800, E-mail: cyanani@ug.edu.gh; agbekoen@yahoo.com The Association of Korean Geoscience Societies and Springer 2018