학술논문

Joint inversion of surface wave and gravity data reveals subbasin architecture of the Congo Basin
Document Type
Academic Journal
Source
Geology (Boulder). 49(7):810-815
Subject
18|Geophysics - solid Earth (tectonophysics)
20|Geophysics - applied (geophysical surveys & methods)
Africa
African Plate
basins
body waves
Central Africa
Congo Basin
Congo Democratic Republic
continental crust
crust
elastic waves
geophysical methods
geophysical surveys
gravity methods
guided waves
inverse problem
plate tectonics
Rayleigh waves
S-waves
salt tectonics
sedimentary basins
seismic waves
seismograms
surface waves
surveys
tectonics
three-dimensional models
transpression
velocity structure
Language
English
ISSN
0091-7613
Abstract
We investigated the architecture of the greater Congo Basin, one of the largest and least-well-studied sedimentary basins on any continent. Seismograms from a large number of M > 4.5 earthquakes within and surrounding the African plate were used to make event-to-station Rayleigh wave group velocity measurements between periods of 5 and 100 s. Group velocities for discrete periods across the basin, obtained by inverting the event-station measurements, were jointly modeled with gravity data to obtain a three-dimensional S-wave and density model of the basin. The model corroborates the existence of two previously suggested subbasins, one to the north and one to the south, each ∼8 km deep and separated by an east-west structural high. Our results favor a salt tectonics origin for the structural high but cannot rule out uplifted basement rock. The northern subbasin is offset to the west from the southern subbasin, consistent with previous studies suggesting sinistral motion along basement faults during periods of transpressional tectonics in late Neoproterozoic-early Paleozoic times.