The soil profiles of the City of Butembo show « stone-lines » in the open air and over large areas. The study of these « stone-lines » poses a problem of genesis given the often questionable interpretation of the particle size, mechanical and technical analyzes intended to prove the autochthony and the allochtony of the constituent materials.
Allochtony at close range is easily confused with autochtony with local reworking.
For a good study of the stone lines of the City of Butembo, we used macroscopic and particle size analyzes to assess the shape and size of the materials. The data collected are represented in the form of plates (figures) and graphs for better analysis.
The documentary technique has been restricted to works that fit the research theme.
As results, the stone lines of the City of Butembo are based on level II of the altered source rock. These « stone-lines » are heterometric with a predominance of pebbles and pebbles (28%), gravels (23%) and coarse sands (10%). Fine materials account for a total of 31%, synonymous with very intense erosion.
Some « stone-lines » are located between the A (black or bluish) and B (yellow or red) horizons. These stone-lines are mixed or holometric, and their thickness is reduced (less than 3m), but also their materials are joined or not. Only one “stone line” is double on steep slopes and all the « stone-lines » have undulations.