Appraisal of Structures, Alteration And Deformational Phases of Rambi Gold Target, Western Kenya
Abstract:
Rambi gold prospect is located in southwest of Busia-Kakamega Greenstone Belt. The target lies at the inter section of latitude 0° 3′ 59.53″N longitude 40° 19′ 6.80″E and has been worked for gold since the 1930s. As promulgated by the colonialists, the mineralization model conforms to a quartz-vein-hosted gold system lying within a shear zone. Besides this compact historical information, Rambi as a target lacks sufficient geological information to advance mineral exploration. This study was set to appraise the gold prospectivity of Rambi as a target through an integrated modernized exploration approach. This approach was aided majorly by assess ing the Airborne magnetic and geochemical datasets. Through the investigation of magnetic data, geological structural pattern encompassing mineralization was realized through enhancement of the primary images. Geochemically, X-Ray Diffraction analysis of eight representative samples in this study were successfully carried out to investigate alteration minerals. Illite and kaolinite stand out as major clay alteration minerals over the sheared/altered potential zones. Petrographic analysis of altered rock samples elucidated the alter ation level of the rocks. Shear lineaments reveal two main deformation episodes in the area as supported by analysis from the fabric diagrams (Rose Diagram). Majorly, the lineaments are grouped into Deformation-1 (D1), Deformation-2 (D2) and Deformation-3 (D3) following the different deformational phases in relation to one another. Major finding are the two main internal shear structures of approximately 1Km strike length, located within the main shear. Similar comparative structures have been attributed to many of the world-class ore deposits, e.g. the Kundana Goldfield in Western, Australia.
