New Data on the Structure of Sedimentary Cover at the Cape Verde Seamount and the Cape Verde Basin (Central Atlantic) Based on Continuous Seismic Profiling Data

摘要

The transition zones between oceanic and continental lithospheres at Atlantic-type margins remain poorly studied. The data available indicate that these regions are distinguished by specific tectonic and igneous activity. The results of several expeditions conducted by the Geological Institute near the rise of the African continental slope south of Cape Verde Islands support this statement. The systems of transform fracture zones (TFZ) that extend to the south of the Fifteen Twenty TFZ pinch out in this area. The near-latitudinal linear ridges and troughs that serve as the eastern flanks of the Vema, Doldrums, Arkhangelsky, and Vernadsky TFZs of the MAR are cut off by the WNW-trending Cabo Verde Escarpment near the African continental slope. This escarpment probably lies at the extension of the Mercury TFZ. Therefore, continuous seismic profiling (CSP) was carried out during Cruise 16 of the R/V Akademik Ioffe (2004) along the 11°31.2′ N, 22°40.2′ W-10°7.8′ N, 24°4.2′ W profile in order to study the structure of sedimentary cover and its basement at the African continental slope south of the Cape Verde Islands, where the manifestation of tectonic activity was expected with certitude. The SW-ori-ented 220-km-long profile (Fig. 1) crosses the transition zone between the Cape Verde Seamount and the Cape Verde Basin divided by the Cabo Verde Escarpment.