TITLE:
Structure of the Crust Beneath the South Western Cameroon, from Gravity Data Analysis
AUTHORS:
Marcel Jean, E. J. M. Abate, P. Njandjock Nouck, H. E. Ngatchou, V. Oyoa, C. T. Tabod, E. Manguelle-Dicoum
KEYWORDS:
South Western Cameroon, EGM2008, Bouguer Anomaly, Spectral Analysis, Moho Discontinuity
JOURNAL NAME:
International Journal of Geosciences,
Vol.7 No.8,
August
15,
2016
ABSTRACT: The study area is located in the south
western Cameroon and includes part of the Cameroon Volcanic Line (CVL).
Volcanic activity has been recorded in this area, precisely on the Mount
Cameroon which recently erupted in 2002. In addition, deadly carbonic gas was
emitted by crater lakes (Monoun and Nyos) in 1984 and 1986 respectively.
Potential field model EGM2008 has been used to investigate the structure of the
crust. A regional/residual separation is performed using upward continuation
and polynomial separation methods. The results from this operation show a
similarity between the regional anomalies resulting from both methods. The
regional anomaly maps present an increasing gradient trending ENE-WSW above and
below latitude 5?N. Moreover, six nearly parallel profiles were drawn on the
CVL in addition to two other profiles at the northern edge of Congo craton.
These profiles were used to estimate the depths of the Moho discontinuity and
some shallow sources by the means of the Bouguer and the residual anomalies
respectively. Theresultsshow that the Moho discontinuity
depths vary from 19 - 25 km (under Mount Cameroon) to 28 - 34 km (in Kumbo),
while the southern neighbouring zone presents a Moho discontinuity depth
ranging between 23 - 31 km (in Ngambe) and 22 - 32 km (in Eseka). These
findings agree with the previous seismic and gravity researches lead in the
area. EGM2008 is therefore a reliable tool to investigate the subsurface
structures.