https://doi.org/10.1306/5D25C55F-16C1-11D7-8645000102C1865D
The Magdalena River of Colombia is prograding its delta rapidly onto the slope that leads north into Colombian basin of the Caribbean. Results of this encroachment are intermittent slope failures that break the jetties at the river mouth and sever the cables on the sea floor outside. Another possible result of the delta encroachment was indicated from the work of a Scripps Institution expedition which led to the discovery of steep-sided domes rising as much as 200 m above the sea floor in water depths of 900-1,200 m. Subbottom profiling showed that these domes, about 1 km wide, have intrusive relations to the foreset beds and can be traced down to at least 700 m below the bottom. The profiles indicate that the domes generally are flanked with ring depressions, which are underlain by downbent strata, in contrast to the usual upbending of strata flanking salt domes. One explanation for these diapirs is that they are giant mudlumps somewhat akin to those off the passes of the Mississippi. Alternatively, they may be mud volcanoes such as are found on the adjacent lands.