Teleseismic events recorded by stations located in the Adamawa Plateau have been treated using the inversion method of receiver functions. These six stations are part of a network of 32 large strip seismic stations in...Teleseismic events recorded by stations located in the Adamawa Plateau have been treated using the inversion method of receiver functions. These six stations are part of a network of 32 large strip seismic stations installed in Cameroon between 2005 and 2007. This method allowed us to investigate the lithospheric mantle in that region. The results obtained from the velocity model have been compared to some existing results in this region. These results show the existence of a thick crust having an average thickness of about 35.2 km and a corresponding S wave velocity of 3.7 km/s. For an average S wave velocity of 4.4 km/s the lithospheric mantle appears to be thin in nature and has a thickness that varies from 39 km and 49.6 km. Beyond the lower lithospheric mantle, there exists a low velocity zone, whose thickness varies between 20 km and 43.9 km. The variation of the low velocity zone leads to variation of the lower boundary of the lithospheric mantle boundary at the depths ranging from 73.8 km and 85 km.展开更多
The quantitative interpretation of gravity anomalies due to shallow structures needs separation between long wavelength anomalies(regional anomalies) and short wavelength anomalies(residual anomalies).The regional-res...The quantitative interpretation of gravity anomalies due to shallow structures needs separation between long wavelength anomalies(regional anomalies) and short wavelength anomalies(residual anomalies).The regional-residual field separation can be carried out using the polynomial method.In this case, the so-called regional field of order n is treated as a polynomial of degree n.The present study shows that the degree n must vary between a smallest value n_(min) and a maximum value n_(max).This article presents a method to process gravity data that allows determination of n_(min) and n_(max) for a given study area.We apply the method to gravity data of the South-West Cameroon zone.In this chosen study area, we find that regional anomaly maps of orders ranging from 1 to 9 and residual anomaly maps of orders ranging from 1 to 8 can be used for suitable interpretation.The analyses show that one may need residual anomaly maps of several orders to perform satisfactory quantitative interpretation of the different intrusive bodies found in a given area.展开更多
文摘Teleseismic events recorded by stations located in the Adamawa Plateau have been treated using the inversion method of receiver functions. These six stations are part of a network of 32 large strip seismic stations installed in Cameroon between 2005 and 2007. This method allowed us to investigate the lithospheric mantle in that region. The results obtained from the velocity model have been compared to some existing results in this region. These results show the existence of a thick crust having an average thickness of about 35.2 km and a corresponding S wave velocity of 3.7 km/s. For an average S wave velocity of 4.4 km/s the lithospheric mantle appears to be thin in nature and has a thickness that varies from 39 km and 49.6 km. Beyond the lower lithospheric mantle, there exists a low velocity zone, whose thickness varies between 20 km and 43.9 km. The variation of the low velocity zone leads to variation of the lower boundary of the lithospheric mantle boundary at the depths ranging from 73.8 km and 85 km.
文摘The quantitative interpretation of gravity anomalies due to shallow structures needs separation between long wavelength anomalies(regional anomalies) and short wavelength anomalies(residual anomalies).The regional-residual field separation can be carried out using the polynomial method.In this case, the so-called regional field of order n is treated as a polynomial of degree n.The present study shows that the degree n must vary between a smallest value n_(min) and a maximum value n_(max).This article presents a method to process gravity data that allows determination of n_(min) and n_(max) for a given study area.We apply the method to gravity data of the South-West Cameroon zone.In this chosen study area, we find that regional anomaly maps of orders ranging from 1 to 9 and residual anomaly maps of orders ranging from 1 to 8 can be used for suitable interpretation.The analyses show that one may need residual anomaly maps of several orders to perform satisfactory quantitative interpretation of the different intrusive bodies found in a given area.
