International Journal of Geosciences, 2021, 12, 739-762
https://www.scirp.org/journal/ijg
ISSN Online: 2156-8367
ISSN Print: 2156-8359
DOI: 10.4236/ijg.2021.129042 Sep. 1, 2021 739 International Journal of Geosciences
Geochemistry of Sedimentary Rocks from the
Nkapa Formation, North Western Part of the
Douala Basin, Cameroon: Implications for
Provenance, Tectonic Setting and
Paleoenvironmental Conditions
Florence Njinto Kwankam
1*
, Christopher Mbaringong Agyingi
2
, Josepha Foba-Tendo
3
,
Cheo Emmanuel Suh
2,4
1
Department of Petroleum Engineering, National Higher Polytechnic Institute (NAHPI), The University of Bamenda, Bambili,
North West Region, Cameroon
2
Department of Geology, Faculty of Science, The University of Bamenda, Bambili, North West Region, Cameroon
3
Department of Chemistry, University of Buea, Buea, South West Region, Cameroon
4
Department of Geology, University of Buea, Buea, South West Region, Cameroon
Abstract
The Douala sedimentary basin in Cameroon is the main gas prospective basin
in the country and has witnessed a number of investigations in this regard.
The Nkapa Formation is one of the basin’s principal rock units and here we
analyzed samples from sediments comprising this formation in order to con-
strain their provenance, tectonic setting and depositional environment using
geochemical traits. Major and trace elements were analyzed by inductively
coupled plasma mass spectrometry. Elemental ratios provide information on
geochemical signatures of Eu/Eu ratios of the sandstones and shales, suggest-
ing the provenance of the sediments was felsic from continental rock proto-
liths. Calculated K
2
O/Na
2
O ratios > 1 is reminiscent of quartz-rich sediments
deposited in passive margin (PM) environments with significant terrigenous
input. The elemental ratios La/Sc, La/Ca, Th/Sc, and Th/Co suggest that the
sediment sources are felsic and mafic in nature. The clastic sediments were
normalized using North American Shale Composite (NASC). The Ni/Co and
V/(V + Ni) ratios reveal that the sediments were deposited under variable
conditions including euxinic, dysoxic and anoxic. Overall, the evidence from
discrimination diagrams using major and trace elements suggest that the se-
diments were derived from mostly Passive margins (PM) and continental isl-
and arc (CIA) with minor Oceanic island arch (OIA) sources. Limestones
from the studied area at Kompina, rich in calcium carbonate above 98.5%
How to cite this paper: Kwankam, F.N.,
Agyingi, C.M., Foba-Tendo, J. and Suh,
C.E. (2021) Geochemistry of Sedimentary
Rocks from the Nkapa Formation, North
Western Part of the Douala Basin, Came-
roon: Implications for Provenance, Tec-
tonic Setting and Paleoenvironmental Con-
ditions. International Journal of Geosciences,
12, 739-762.
https://doi.org/10.4236/ijg.2021.129042
Received: July 7, 2021
Accepted: August 29, 2021
Published: September 1, 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