This work deals with the geochemistry of lava and pyroclastic rocks of the Lac Vert cone. We present the results of geochemicals analyzes of major and traces elements performed at the University of Naples. The results showed that these rocks are primarily nephelinite - ultrabasic very rich in iron and have calc-alkaline affinities. The geochemical compositions of lavas and pyroclastic rocks of cone of Lac Vert demonstrated a positive correlation with lavas from the 1977 and 2002 Nyiragongo eruption. The different graphs showed that these lavas and pyroclastic rocks are associated with divergent plate margins (basalt sea floor, OFB); they originated in the spreading seafloor zones specifically in alkaline basalts sclerosis on the island of the ocean. The petrogenetic model likely established through geochemical analysis shows that these rocks are from a calc-alkaline volcanism developed in an oceanic expansion and then they finally migrated to a framework of transitional continental rift before the eruption. Partial melting and fractional crystallization of mantle rich in Anorthite, olivine, clinopyroxene orthopyroxene, magnetite,... would have generated the magma. These geochemical and petrological characteristics of the lavas and pyroclastic rocks around the Lac Vert cone are the same as those of the Nyiragongo. This justifies the affiliation of the Lac Vert cone to Nyiragongo volcano.
This work describes the geochemical characteristics of rocks of the Bitungulu lava flow of the January 17, 2002 Nyiragongo volcano eruption. In addition to the description in situ, samples of these rocks were analyzed in the University of Lubumbashi laboratory. Results show a high concentration of silica and mineralization dominated by nepheline. These rocks are basalts but they are close to trachy-basalts.
This work is a contribution to the knowledge of the geotechnical characteristics of soils of Baraka and especially at port Mushimbakye. We present the results of tests of permeability in situ, of compaction, of granulometric analysis, of Atterberg limits and of direct shear tests. All these have helped to classify the soil of Baraka silty loam, moderately plastic and hard, bad qualities but good for compaction and construction. These soils are stable and of high permeabilities. Here permeability In situ varies according to the texture and soil moisture. We also present the studies of foundation at the port of Mushimbakye and MWAMBANGU. To these sites, allowable stresses are large and the insoles squares are the only that can withstand large loads. A Mushimbakye and Mwambangu the allowable stresses are respectively for square footings 218.1KN / m