International Journal of Geosciences, 2021, 12, 307-328
https://www.scirp.org/journal/ijg
ISSN Online: 2156-8367
ISSN Print: 2156-8359
DOI: 10.4236/ijg.2021.124017 Apr. 15, 2021 307 International Journal of Geosciences
Zircon Trace Element Geochemistry and
Ti-in-Zircon Thermometry of the Ngazi-Tina
Pan-African Post-Collisional Granitoids,
Adamawa Cameroon
Alexis Hamdja Ngoniri
1
, Habib Dadjo Djomo
2
, Timoleon Ngnotue
1*
, Patrick Ayonta Kenne
1
,
Ghislain Ngassam Mbianya
1
, Sylvestre Ganno
3*
, Jean Paul Nzenti
3
1
Department of Earth Sciences, University of Dschang, Dschang, Cameroon
2
Institute for Geological and Mining Researches (IGMR), Yaounde, Cameroon
3
Department of Earth Sciences, University of Yaoundé I, Yaounde, Cameroon
Abstract
In Cameroon, the Ngazi-Tina region belongs to the Adamawa-Yade domain
of the Pan-African Central African Fold Belt (CAFB). It is composed of two
petrographic types: quartz-monzonites (majority) and nepheline syenites.
Two morphological types, prismatic and pyramidal, were recognized in the
zircon grains samples. These zircon types display internal structures typical of
magmatic zircons. Zircons separated from the Ngazi-Tina samples contain
higher abundances of Hf (close to 8000 ppm) and moderate trace elements
(Y, Th, U, Nb, Ta) and REE contents, suggesting a variable degree of mag-
matic evolution. The chondrite-normalized REE patterns of zircons are cha-
racterized by LREE depletion relative to HREE with positive Ce and negative
Eu anomalies, typical of magmatic zircons. The high Hf content together with
high Ce/Ce*, Th/U, Zr/Hf ratios suggest magma crystallization under variable
oxidation and oxygen fugacity. The application of Ti-in-zircon thermometer
reveals crystallization temperatures ranging from 678˚C to 811˚C and 658˚C
to 768˚C for quartz monzonites and nepheline syenites respectively. These
features indicate probably a partial melting of continental crust as the source
of these zircons grains and emplacement in the magmatic-arc setting.
Keywords
Granitoids, Zircon Geochemistry, Ti-in-Zircon Thermometer, Continental
Crust, Ngazi-Tina, Adamawa-Yade Cameroun
How to cite this paper: Ngoniri, A.H.,
Djomo, H.D., Ngnotue, T., Kenne, P.A.,
Mbianya, G.N., Ganno, S. and Nzenti, J.P.
(2021) Zircon Trace Element Geochemistry
and Ti-in-Zircon Thermometry of the Nga-
zi-Tina Pan-African Post-Collisional Grani-
toids, Adamawa Cameroon. International
Journal of Geosciences, 12, 307-328.
https://doi.org/10.4236/ijg.2021.124017
Received: February 25, 2021
Accepted: April 12, 2021
Published: April 15, 2021
Copyright © 2021 by author(s) and
Scientific Research Publishing Inc.
This work is licensed under the Creative
Commons Attribution International
License (CC BY 4.0).
http://creativecommons.org/licenses/by/4.0/
Open Access