The Oldest Rocks in West Africa: SHRIMP Zircon Age for Early Archean Migmatitic Orthogneiss at Kaduna, Northern Nigeria

TLDR: Zircons extracted from a migmatitic orthogneiss of granodioritic composition from Kabala, Kaduna area of northern Nigeria, yielded a SHRIMP 207Pb/206Pb zircon age of Ma, indicating that Early Archean crust is exposed in the Nigerian basement complex.

Abstract: Zircons extracted from a migmatitic orthogneiss of granodioritic composition from Kabala, Kaduna area of northern Nigeria, yielded a SHRIMP 207Pb/206Pb zircon age of \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $3571\pm 3$ \end{document} Ma, indicating that Early Archean crust is exposed in the Nigerian basement complex. The Kabala gneisses are the oldest rocks known so far from the West African shield, and indications for rocks of similar age have recently been reported from the Reguibat and Kenema‐Man shields in Wes...