Bilingual Publishing Group

  Keywords: Akure Nigeria Geochemical trends In-situ weathering profile Kaolinitic ABSTRACT Akure area in southwestern Nigeria falls within the basement complex  underlain by migmatite, quartzite granite and charnockite. Geochemical  features of these crystalline rocks and their overlying in-situ weathering  profiles are investigated and reported. Analytical result from ICP-MS  facility at the University of Malaya reveals average SiO2 content in  quartzite (91.1%), granite (73.8%), migmatite (67.4%) and charnockite  (58.6%) categorize the rocks as siliceous. SiO2 contents in the weathering  profiles above these rocks are 61.9%, 60.2%, 52.2% and 54.6%  respectively. Alumina contents in the weathering profiles overlying  quartzite (23.8%), granite (19.9%), migmatite (26.3%) and charnockite  (24.3%) are substantially higher than the precursor rocks. In the same  order, average alkali (Na2O+K2O) contents in the profiles are 3.38%, ...