<![CDATA[Abstrak Pulau Bangka merupakan salah satu daerah dengan potensi timah dan mineral ikutan timah yang besar. Potensi timah danmineral ikutan timah dijumpai sebagai endapan primer dan endapan plaser. Endapan plaser di pulau Bangka dikelompokkan sebagai endapan undak sungai Purba dan Formasi Ranggam. Formasi Ranggam merupakan endapan sedimen sungai yang berumur Tersier. Formasi Ranggam tersusun atas 9 litofasies, yaitu Fasies Konglomerat Pasiran (SG), Batupasir Halus (FS),Batupasir Konglomeratan (GS), Batulanau Tufan (TSL), Batupasir Silang-siur Planar (S-p), Batupasir Konglomeratan Gradasi Terbalik (SG-i), Batulempung (CL), Batulempung – Batupasir (CLS), Batupasir Tufan (TS). Berdasarkan pada Elemenarsitekturnya Formasi Ranggam diendapkan dalam lingkungan sungai sebagai endapan channel fill, floodplain, natural levee,dan crevasse splay. Kata kunci: Bangka, Formasi Ranggam, Litofasies, Elemen Arsitektur Abstract Bangka Island is one of the areas with a large potential for tin and tin associated minerals. The potential for tin and lead associated minerals is found as primary deposits and plaser deposits. Plaser deposits on the island of Bangka are grouped as deposits of the ancient river steps and the Ranggam Formation. The Ranggam Formation is a Tertiary river sediment deposit. The Ranggam Formation is composed of 9 lithofacies, namely the Facies of the Pasiran Conglomerate (SG), Fine Sandstone (FS), Conglomerate Sandstone (GS), Tufan Silicate Sandstone (TSL), Planar Cross-sectional Sandstone (Sp), Reverse Gradation Conglomerate Sandstone (SG-i ), Claystone (CL), Claystone - Sandstone (CLS), Tuffan Sandstone (TS). Based on its architectural elements, the Ranggam Formation is deposited in a river environment as channel fill, floodplain, natural levee, and crevasse splay deposits. Keywords: Bangka, Ranggam Formation, Litofasies, Architectural Elements]]>
