Geochemistry of tertiary-quaternary lavas of Mt. Oku Northwest Cameroon

Authors

  • Njilah Konfor University of Yaounde I
  • Robert Temdjim University of Yaounde I
  • Charles Richard University of Yaounde I
  • Nzolang Ghogomu University of Yaounde I
  • Rose Tchuitchou University of Yaounde I
  • Humphery Ajonina Institute for Mining and Geological Research

Keywords:

Oku, stratovolcano, geochemistry, K-Ar ages, compositional gap

Abstract


The Oku massif occupies the central position amongst the continental sector volcanoes of the Cameroon Volcanic Line (CVL). Field observations, petrographic major, trace and REE geochemistry show that lavas are basanite/alkali basalt-trachyte/rhyolite suited with a distinct compositional gap within the benmoreite field. This gap, which cannot be explained by sampling bias, may therefore reflect density filtration within the magmatic plumbing system. However, accumulation and fractionation of major mineral phases: pyroxenes, olivines and plagioclases appear to have controlled magma evolution. Fractional crystallization has been shown to be the major differentiation process that gave rise to the spectrum of magmas of this stratovolcano though crustal contamination in high level magma chambers cannot be precluded in this intraplate continental setting. K-Ar age determinations show that the volcanic activity in Mt. Oku occurred in three distinctive episodes 25-22 Ma, 18-14 Ma and < 1 Ma. There is no evidence for volcanic activity between 14 and 1Ma. Less than 1 Ma BP, activity resumed creating abundant cones and craters.

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Author Biographies

Njilah Konfor, University of Yaounde I

Department of Earth Sciences, Faculty of Science

Robert Temdjim, University of Yaounde I

Department of Earth Sciences, Faculty of Science

Charles Richard, University of Yaounde I

Dept. of Plant Biology

Nzolang Ghogomu, University of Yaounde I

Dept. of Plant Biology

Rose Tchuitchou, University of Yaounde I

Dept. of Plant Biology

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Published

2014-07-31

How to Cite

Konfor, N., Temdjim, R., Richard, C., Ghogomu, N., Tchuitchou, R., & Ajonina, H. (2014). Geochemistry of tertiary-quaternary lavas of Mt. Oku Northwest Cameroon. Revista Facultad De Ingeniería Universidad De Antioquia, (40), 59–75. Retrieved from https://revistas.udea.edu.co/index.php/ingenieria/article/view/20149