TY - JOUR
T1 - Effective elastic thickness and crustal thickness variations in west central Africa inferred from gravity data
AU - Poudjom Djomani, Y. H.
AU - Nnange, J. M.
AU - Diament, M.
AU - Ebinger, C. J.
AU - Fairhead, J. D.
PY - 1995
Y1 - 1995
N2 - The west central African region is characterized by various geological features: Cretaceous rifts (Benue), Tertiary domal uplift (Adamawa volcanic uplift), Tertiary-Recent volcanoes (Cameroon Volcanic Line or CVL),Tertiary sedimentary basins (Chad basins), and cratonic region (Congolesecraton). In this study, we investigate the relationship between these tectonic features and the flexural rigidity of the lithosphere in Cameroon, in terms of effective elastic thickness (Te), by the use of the coherence function analysis. For that purpose, we use a new dataset of ∼32,000 gravity and topography points from Cameroon and the adjacent countries. The Te contour map deduced from this study shows a good relationship between the tectonic provinces and the rigidity of the lithosphere, the minima (14–20 km) are beneath the active rifted and volcanic areas (Benue, CVL, and Adamawa), and the maxima (∼40km) correspond to the Archean reworked unit in Congo. A spectral analysis of the gravity data is performed to determine the crust-mantle boundary in the setectonic provinces. The crustal thickness (Tc) contour maps hows a variation from 14 km to about 45 km, consistent with other geophysical data. The lower values (14–20 km) are obtained in central Cameroon on the Adamawa uplift, and the highest values are found in southern Cameroon (Archean reworked Congolese craton). Comparing Te and Tc values shows that there is generally a positive correlation between the two parameters, with an exception in Chad where this correlation is rather negative.
AB - The west central African region is characterized by various geological features: Cretaceous rifts (Benue), Tertiary domal uplift (Adamawa volcanic uplift), Tertiary-Recent volcanoes (Cameroon Volcanic Line or CVL),Tertiary sedimentary basins (Chad basins), and cratonic region (Congolesecraton). In this study, we investigate the relationship between these tectonic features and the flexural rigidity of the lithosphere in Cameroon, in terms of effective elastic thickness (Te), by the use of the coherence function analysis. For that purpose, we use a new dataset of ∼32,000 gravity and topography points from Cameroon and the adjacent countries. The Te contour map deduced from this study shows a good relationship between the tectonic provinces and the rigidity of the lithosphere, the minima (14–20 km) are beneath the active rifted and volcanic areas (Benue, CVL, and Adamawa), and the maxima (∼40km) correspond to the Archean reworked unit in Congo. A spectral analysis of the gravity data is performed to determine the crust-mantle boundary in the setectonic provinces. The crustal thickness (Tc) contour maps hows a variation from 14 km to about 45 km, consistent with other geophysical data. The lower values (14–20 km) are obtained in central Cameroon on the Adamawa uplift, and the highest values are found in southern Cameroon (Archean reworked Congolese craton). Comparing Te and Tc values shows that there is generally a positive correlation between the two parameters, with an exception in Chad where this correlation is rather negative.
UR - http://www.scopus.com/inward/record.url?scp=0029476547&partnerID=8YFLogxK
U2 - 10.1029/95JB01149
DO - 10.1029/95JB01149
M3 - Article
AN - SCOPUS:0029476547
SN - 0148-0227
VL - 100
SP - 22047
EP - 22070
JO - Journal of Geophysical Research
JF - Journal of Geophysical Research
IS - B11
ER -